Back when SMD was new we bought an expensive hot air rework station for removing and replacing large quad flat packs. We got trained by the manufacturer's rep, bought the correct nozzles, and programmed the temp/time/airflow settings.The first time we tried to repair a board, the nearby SMD resistors and capacitors went floating away like so many tiny boats. The boards we had trained on had a bigger gap between IC and passives.
***** Unfortunately to access the service menu for most TV's you need a remote, and Dave's TV doesn't have one. My suggestion is to buy a universal remote and try using the standard Samsung service menu code, it's the only thing I can think of to do.
Thank you pXnEmerica. I'm about to replace some caps on it tonight that were bad on the PS board, but if that doesn't take care of it, it'll be the next thing I try!
Yeah, I'm hoping he continues with it as well. These repair videos are my favorite. Repairing home electronics is something I enjoy doing, something I would like to be better at, and these videos really help teach how to go about narrowing down the problem.
***** That's true. Also I just checked the service manual for Dave's TV and he can apparently access the Service Menu with any brand universal remote by pressing Power Off -> Info -> Menu -> Mute -> Power On.
90% of the stuff you talk about usually is about stuff i don't understand, but still i can't stop watching the whole video. I'm convinced that in a few years i will be re-watching these, so be sure to keep them online! Great vid's, love them!
I have a similar hacky oven setup, with an Arduino running the PID stuff and controlling the heater element. I mounted a hobby servo on the base plate in front of the oven and connected it to the door handle, so when the controller gets to the cooldown stage it pulls the door partly open. That helps the temperature drop much more quickly
Dave, You can cut away the melted plastic enough to fit the connector back on. I would really like to see you fix this TV. And Dave, You are the one who inspires me to at least try to fix things because it's what I like to do. I like to tinker and fix stuff and if it cannot be fixed I scrap it for parts. I tore down an unfixable LCD TV and harvested a nice amp board which I've used to build a amp boombox. It had detachable speakers so I used those for a car stereo.
I've never heard of this, so this was the perfect way for me to learn about it. I learned it can ruin some things. I learn a LOT from failure and being shown and told about other people's failures.
The obvious thing to do would have been to check all the TMDS pairs from the processor board for good clean signal with your nice 1ghz scopes, next to replacing that t-con board, before ever considering to reflow anything. These TV's generate so little heat that its extremely unlikely that any soldering has become loose over time. Furthermore, I would have just ripped all the melted plastic off the board and made sure it still works before bothering to continue further desoldering and ordering new plugs, etc.
This model is from 2009 when we still wave soldered the through-hole components in Samsung, but in 2010 we started to mount all the through-hole components including the tuner by machine and soldered the board in the reflow owen.
You don't need any fancy connectors; get in there with some 37AWG and hardwire the ribbon cable to the board! It's not that hard; we do it every day where I work :D
This is why I use a hot air gun for reflowing. I put the heat on the components that can take it, but I avoid those that need to be protected, such as the plastic connectors.
Been there done that got the t shirt. Fortunately on something even less valuable than a TV mainboard. Through hole USB connectors really don't like reflow oven heat :)
Awesome video! Even though I feel for you melting those connectors, these are the type of videos I love on the EEVBlog channel! And please don't give up on the TV, this is like a good detective series with audience input.. Thumbs up!
Most through hole types of connectors are intended to survive either a solder wave or hand soldering. I've even had to build connectors that have stripped wire coming out the back to pull heat away from connector pins like a heat sink when hand soldering on ground plains. Source: I build PCBs for water testing equipment.
I'm an oldie more at home with CRT technology. I was given a Samsung TV very similar to the one you were working on and displaying very similar faults. As you might imagine, I didn't manage to fix it but I did learn something about how these things work, not least from watching your heroic videos. I wonder if this is a particular fault with this Samsung design. Normally LCD displays go on for ever without failure. One thought: it's not a good idea to use any liquid cleaners on the screen that might seep down into the electronics below.
I was wondering if the heating element is at the back of the oven. I'd guess that would make it quit a bit hotter across the back. It might be hotter at the back anyway as the glass probably lets quite a bit of heat out. I guess that's the end of the repair job though, shame that was an interesting bug.
I have made that mistake myself on my first run of the reflow oven and I was thinking exactly that while watching your last video where you reflowed the board. However I've never had a proper SMD connector designed for reflow, melt in my cheap reflow oven, so I wouldn't blame the oven in your case. Those connectors just weren't designed for reflow. That Samsung board first gets populated with the SMD parts, goes through reflow, then gets populated with through hole parts and goes through the wave soldering process.
Dave, you crack me up. All you needed to do was get a second hand t-con board. 99% sure that was your problem. if it was not the problem you could have sent it back and all it would have cost you is a few bucks on postage. Duuuugghh. Still a good lesson learned.
As a general rule? We run through hole connectors through our reflow oven and selective solder or wave solder others, depends on the plastic, not through hole specifically. Test first.
Dave. I did couple of reflows on Dell and HP Laptops, I’ve used: heat gun, temp sensor and chronometer to follow the heat/cool curve & timings. Shielded the target area from the rest of the board with aluminium plates and foil. Dell died after 6 month. HP is still running after 2 years.
Melted connectors to close to the radiative surface and edges. Also have hot air convection going through the small gap between the board and the wall.
That's what I like about your stuff Dave ... Bugger ups do happen! Find out why, learn, explain, sort it ... Don't try to hide it ... Great, it's called engineering 😂
Twin row headers might work to test, if the spacing is right when they are still upright. If it work, replace with the right part, if not, desolder and lose nothing.
A great video. Thank you, but I feel I should point out the following. I know you used a generic datasheet (in this case the HiRose DF13 series connector) but @ 6:02 the note stating "60 sec max" is ONLY related to the temperature of the solder when at liquidus, in other words, when it starts soldering (217°C - 221°C for lead free) and is only there to ensure a good reliable solder joint. Any longer than 60 seconds AT LIQUIDUS would NOT melt the part, but could increase the risk of a poor solder joint and could jeopardise its electrical contact, especially if the Printed Circuit Board undergoes thermal cycling during its operation. The '10sec max' reference on the graph is the optimal limit when at PEAK temperature, in this case (250°C). Peak temp is normally much higher than soldering temp to ensure the WHOLE PCB has heated sufficiently. If the PCB has areas that are heavily populated with components the PCB may not heat up evenly. 'Lead-free' components (including connectors) are designed to easily withstand temperatures of up to 260°C, but for optimal performance the temperature should be kept below the stated 'Peak' value. Additionally, just as a side note, the "Max 230°C" shown on the graph is related to the time at liquidus. The 'preheating' shown on the graph is there to ensure the flux with the solder has sufficient time to remove any oxides on the component leads before the solder becomes liquidus. This should guarantee a clean joint. Generally the flux will become 'active' and begin to remove oxides at approx 150°C. I look forward to seeing your other videos. I especially like the "Worlds worst tablet". Truly shocking.
If I remember correctly, re-flowing doesn't take all that long, so what if you wrapped some al foil over the connectors to reflect the heat? I know that that woild basically be making a small oven around it eventually but I think it'd reflect the heat to begin with, and considering the short exposure time, I think it might work.
Darren Jacobson Depends, sometimes a reflector can trap heat inside the system. It's in part a timing differential. However, clamping aerogel mats to the surface can work.
Darren Jacobson You want to look at the thermal transfer vectors. Mylar is good for reflecting radiative heat, as in from IR. An oven like that will have a lot of convective heat though, and as an aluminized plastic, mylar will likely melt. That's one issue with foil, aluminum itself is thermally conductive. That's one reason it's a prime heatsink material. Aerogel however is an air-pocket insulator, usually ceramic or silica based. You'd want to be using an insulator like that to block the convective vector. It can be surface aluminized as well to block the radiative vector too.
Same thing for me - multiple times I've been reballing my old graphic card - worked pretty well untill some day I didn't wrapped it very well, so my plastic connectors melted too. Also the capacitors too need to bee wrapped - they don't like high temperature.
The element on an oven will typically get very hot and may exceed what the thermostat believes it to be. This is why if you don't preheat your oven, you can burn your pizza. Especially radiative heat might exceed what you are expecting Dynamic temperature profiles on an oven like this is always going to be tricky. Might be better to preheat it and then just throw the whole board in for a short amount of time to approximate the cuve.
Nice video Dave .. but i still think it might be T-con or those chips on flexible ribon cables..you should check if they are not broken..also static discharge could kill it...who knows..
I've wondered on air circulation for toaster ovens if you couldn't put a metal fan blade on a long shaft into there, powered by an external motor going through the side of the toaster oven, that'd mix the air well during the heating cycle, I'd think?
I've heard of people reflow soldering with heat guns, what are your opinions on that particularly since it would be very difficult to control the heat? I suppose you also risk the possibility of physically moving the solder or smaller components with the force of the air. (many PlayStation 3 yellow light remedies use this method)
I have seen those diy ovens having a fan for the cool-down stage. Won't save your connectors of course, and the danger is that you loose heat trough the hole you have to cut for your fan. Could it work if you put a bit of heat resistant tape on the connectors? This will only help to protect from radiant heat off course.
Thanks again for sharing this head-smacking moment, Dave. Always something to learn. As others have said, please don't give up on this TV repair. I'm eager to see the outcome. One thing, is the problem present on all the other inputs/connectors?
maybe in a Thermal Oven because if u are experienced, most of the failures are caused by cold joints not transmitting well the electrons after u have used the multimeter and nothing looks wrong.
So, is it safe to assume that the melted right-angle connectors were the only things damaged by the oven, or could there be other components damaged by the heat in less obvious ways?
Dave My guess is that its a JST board-to-wire type. Measure your pin pitch and it's a quick lookup of about 5 to 10 types. If it is a JST then just go and request two samples and as long as you're patient, bob's your uncle. Kevin
Its messed up but Ive been looking forward to watching him fix this board since he got it and cant wait for another Samsung tv repair video hope he finishes the project.
I will always cover all plastic connectors with aluminum tape the best I can. You never know... A small fan blowing cold air with an Arduino adjusting the PWM to not let it cool off too quick or slow is also not that difficult for the DIYer
Could wrapping in aluminum foil be enough to protect such connectors from damage? That's how some people protect components while reflowing just one, like some huge BGA of, say, PC graphics card. Or is that method only suitable for IR lamp?
Couldn´t you use bluetack to insulate components from heat while reflowing? Maybe some type of clay? I guess there could be a risk of warping the board, but if the area is small enough, just a couple of connectors, that should be fine though right?
Was the plastic used for the melted connectors different than the ones that didn't melt?🤔 I thought of taking a toaster oven & using it for a m/b pre-heater, but for a whole reflow. Thanks
Hello. Please check if the Tcon equips with a AS15-F IC. It's a very problematic voltage buffer on Tcon boards and it's relatively cheap on ebay. And keep up the good work with the eevblog.
Recently I had to replace some SMD components on a board, right next to the 40-pin 1" header.... I used hear gun for SMDs.... and pin header just melted down ;) I realized that too late.
Would using the convection function (if it has one) on the toaster, er, 'reflow,' oven help with hot spots? That's what I've been doing, but with no real proof it actually helps. Just sounded good in my head.
I really hope you can get this TV to work again. I love repair videos, but it's unfortunate that you always have bad luck with either to difficult or too easy problems. Maybe this time :) don't give up!
How come reflow soldering does not damage components that on their datasheet specify absolute maximum temperatures waaaay lower than what is used during reflow? I can understand soldering with a soldering iron, because it's done very quickly, but reflowing takes a very long time in comparison.
I wouldn't count on *all* SMD components to be re-flow resistant. For example some SMD 20mm fuse holders are made to be soldered on by using a sharp tip iron on the side. The worst thing is that even then they begin to melt around the pads. Terrible trap... especially when the board is designed to be used bare and thus the ugliness is visible.
Not sure whether that does the trick. The GND will get hot and the pin to it will melt the plastic. Same for other pins. The foil only helps against the IR radiation.
I allways reflow with flux and hot air surface mount or not, and last i clean the board with an ultrasonic cleaner. Allways works for me. Interesting video though ;-)
It did seem heavy handed to melt the entire board, particularly dual sided. Hot air if you must but I wouldn't do that without having located the problem. And yes it is rather ridiculous how low temperature plastic they use for connectors. They melt with any process you use, it's so stupid.
EEVblog cool ass video Dave! As you say Murphy gets us all. You talk about it, but it wasn't 100% clear to me. Had you thought about it before hand what methods could you have employed to protected these thru-hole connectors allowing you to reflow the board? For example perhaps the use of foil, facing the board forward towards the door where your previous video (based on memory) showed some cool spots, etc. Interesting stuff. Thanks.
It's just you who made 2 possible mistakes : you either set the temperature too high, or you just left the board inside for too long. I've succesfully used the oven technique on a graphics card, but the 3rd time i did it i was doing some other stuff too i left it inside for a bit longer and the plastic from the dvi connectors melt a bit, still had no trouble using the card. I haven't been able to repair the issues with the card though, i bought it new and basically crashed most of the time, gave me artifacts and stuff, and even after putting it into the oven, it just shown the same issues. Definitely a chip problem somewhere, not necessarily a solder issue.
Back when SMD was new we bought an expensive hot air rework station for removing and replacing large quad flat packs. We got trained by the manufacturer's rep, bought the correct nozzles, and programmed the temp/time/airflow settings.The first time we tried to repair a board, the nearby SMD resistors and capacitors went floating away like so many tiny boats. The boards we had trained on had a bigger gap between IC and passives.
Please don't give up on this TV! Really want to see it fixed, as I'm working on one with the same issue!
Protonus Problem is that Dave don't know what he is doing.
***** Unfortunately to access the service menu for most TV's you need a remote, and Dave's TV doesn't have one. My suggestion is to buy a universal remote and try using the standard Samsung service menu code, it's the only thing I can think of to do.
Thank you pXnEmerica. I'm about to replace some caps on it tonight that were bad on the PS board, but if that doesn't take care of it, it'll be the next thing I try!
Yeah, I'm hoping he continues with it as well. These repair videos are my favorite. Repairing home electronics is something I enjoy doing, something I would like to be better at, and these videos really help teach how to go about narrowing down the problem.
***** That's true. Also I just checked the service manual for Dave's TV and he can apparently access the Service Menu with any brand universal remote by pressing Power Off -> Info -> Menu -> Mute -> Power On.
90% of the stuff you talk about usually is about stuff i don't understand, but still i can't stop watching the whole video. I'm convinced that in a few years i will be re-watching these, so be sure to keep them online! Great vid's, love them!
I have a similar hacky oven setup, with an Arduino running the PID stuff and controlling the heater element. I mounted a hobby servo on the base plate in front of the oven and connected it to the door handle, so when the controller gets to the cooldown stage it pulls the door partly open. That helps the temperature drop much more quickly
Great video Dave! We all learn from our own mistakes, but a lot of us will learn from yours. Your modesty is admirable sir!
At 10:15, check the solder joints on that 36 pin IC. It looks like some of the pins are floating above the pads.
dwDragon88 That's the audio output IC. Unlikely to cause video problems. ;)
envisionelec So if Dave is trying to repair the TV, he's not going to want audio? ...
dwDragon88 Precisely.
dwDragon88 the entire thing belongs in the bin.
+dwDragon88 Who uses the builtin audio capabilities of huge TVs? They sound like ass.
Great information Dave, thanks for sharing.
wow... a trap for old players, i guess. ;)
hahaha
not afraid to show everyone a mistake.
you will be forever young!!! awesome thanks Dave!!
Dave subconsciously did this as he no longer wants to work on this tv.
11:00 seriously!! the first pin of the IC next to C2102 is not connected
:-)
Dave, You can cut away the melted plastic enough to fit the connector back on. I would really like to see you fix this TV.
And Dave, You are the one who inspires me to at least try to fix things because it's what I like to do. I like to tinker and fix stuff and if it cannot be fixed I scrap it for parts. I tore down an unfixable LCD TV and harvested a nice amp board which I've used to build a amp boombox. It had detachable speakers so I used those for a car stereo.
Interesting, this is gonna be the first thing that Dave didn't give up on repairing on video so far!
What's with the peanut butter on your connectors :-)?
Nothing reeks more than the smell of melting plastic.
I've never heard of this, so this was the perfect way for me to learn about it. I learned it can ruin some things. I learn a LOT from failure and being shown and told about other people's failures.
The obvious thing to do would have been to check all the TMDS pairs from the processor board for good clean signal with your nice 1ghz scopes, next to replacing that t-con board, before ever considering to reflow anything. These TV's generate so little heat that its extremely unlikely that any soldering has become loose over time. Furthermore, I would have just ripped all the melted plastic off the board and made sure it still works before bothering to continue further desoldering and ordering new plugs, etc.
This model is from 2009 when we still wave soldered the through-hole components in Samsung, but in 2010 we started to mount all the through-hole components including the tuner by machine and soldered the board in the reflow owen.
This is why I watch your channel.
You don't need any fancy connectors; get in there with some 37AWG and hardwire the ribbon cable to the board!
It's not that hard; we do it every day where I work :D
This is why I use a hot air gun for reflowing. I put the heat on the components that can take it, but I avoid those that need to be protected, such as the plastic connectors.
Steve Packard That is a good solution. Use a reflow oven when initially populating boards, use hot air for rework. At least IMO.
Been there done that got the t shirt. Fortunately on something even less valuable than a TV mainboard. Through hole USB connectors really don't like reflow oven heat :)
Thru hole headers are installed after surface mount components are installed at the factory.
Melted like cheese on a Big Mac, cheezy!
***** I've never seen a big mac with melted cheese before! You must have fancy mcdonalds where you live.
***** mcdonalds products contain actual cheese? No way
503technics you need to reflow your big mac. the cheese is within spec.
Awesome video! Even though I feel for you melting those connectors, these are the type of videos I love on the EEVBlog channel! And please don't give up on the TV, this is like a good detective series with audience input.. Thumbs up!
I reflowed a toasted cheese sandwich the other day. It all went according to plan and it was delicious.
Most through hole types of connectors are intended to survive either a solder wave or hand soldering. I've even had to build connectors that have stripped wire coming out the back to pull heat away from connector pins like a heat sink when hand soldering on ground plains.
Source: I build PCBs for water testing equipment.
I am feeling better about my self, I thought I was the only one capable of doing something like that. Thanks Dave, shit happens. Great videos!!
I'm an oldie more at home with CRT technology. I was given a Samsung TV very similar to the one you were working on and displaying very similar faults. As you might imagine, I didn't manage to fix it but I did learn something about how these things work, not least from watching your heroic videos. I wonder if this is a particular fault with this Samsung design. Normally LCD displays go on for ever without failure.
One thought: it's not a good idea to use any liquid cleaners on the screen that might seep down into the electronics below.
Nice to be open, thank you
I was wondering if the heating element is at the back of the oven. I'd guess that would make it quit a bit hotter across the back. It might be hotter at the back anyway as the glass probably lets quite a bit of heat out. I guess that's the end of the repair job though, shame that was an interesting bug.
Wobblycogs Workshop If it's an IR oven, the glass wouldn't make much difference.
There are two heating elements in the top and two at the bottom.
I have made that mistake myself on my first run of the reflow oven and I was thinking exactly that while watching your last video where you reflowed the board. However I've never had a proper SMD connector designed for reflow, melt in my cheap reflow oven, so I wouldn't blame the oven in your case. Those connectors just weren't designed for reflow. That Samsung board first gets populated with the SMD parts, goes through reflow, then gets populated with through hole parts and goes through the wave soldering process.
Discussing this sort of problem today when reflowing using hot air, kilsl the connectors but the good ol vapour phase oven avoids all that.
Dave, you crack me up. All you needed to do was get a second hand t-con board. 99% sure that was your problem. if it was not the problem you could have sent it back and all it would have cost you is a few bucks on postage. Duuuugghh. Still a good lesson learned.
cymro47 Really? And what's the fun in that?
cymro47 You know he makes a living creating content for youtube, right? This TV has given him 3 vids or so, so far.
As a general rule? We run through hole connectors through our reflow oven and selective solder or wave solder others, depends on the plastic, not through hole specifically.
Test first.
Dave. I did couple of reflows on Dell and HP Laptops, I’ve used: heat gun, temp sensor and chronometer to follow the heat/cool curve & timings. Shielded the target area from the rest of the board with aluminium plates and foil. Dell died after 6 month. HP is still running after 2 years.
Melted connectors to close to the radiative surface and edges. Also have hot air convection going through the small gap between the board and the wall.
Man, I *like* your camera! That's *SUPER* sharp!
that's why SMD component assembling is done before through hole mounting in industry
That's what I like about your stuff Dave ... Bugger ups do happen! Find out why, learn, explain, sort it ... Don't try to hide it ... Great, it's called engineering 😂
Twin row headers might work to test, if the spacing is right when they are still upright. If it work, replace with the right part, if not, desolder and lose nothing.
A great video. Thank you, but I feel I should point out the following. I know you used a generic datasheet (in this case the HiRose DF13 series connector) but @ 6:02 the note stating "60 sec max" is ONLY related to the temperature of the solder when at liquidus, in other words, when it starts soldering (217°C - 221°C for lead free) and is only there to ensure a good reliable solder joint. Any longer than 60 seconds AT LIQUIDUS would NOT melt the part, but could increase the risk of a poor solder joint and could jeopardise its electrical contact, especially if the Printed Circuit Board undergoes thermal cycling during its operation. The '10sec max' reference on the graph is the optimal limit when at PEAK temperature, in this case (250°C). Peak temp is normally much higher than soldering temp to ensure the WHOLE PCB has heated sufficiently. If the PCB has areas that are heavily populated with components the PCB may not heat up evenly. 'Lead-free' components (including connectors) are designed to easily withstand temperatures of up to 260°C, but for optimal performance the temperature should be kept below the stated 'Peak' value.
Additionally, just as a side note, the "Max 230°C" shown on the graph is related to the time at liquidus. The 'preheating' shown on the graph is there to ensure the flux with the solder has sufficient time to remove any oxides on the component leads before the solder becomes liquidus. This should guarantee a clean joint. Generally the flux will become 'active' and begin to remove oxides at approx 150°C.
I look forward to seeing your other videos. I especially like the "Worlds worst tablet". Truly shocking.
If I remember correctly, re-flowing doesn't take all that long, so what if you wrapped some al foil over the connectors to reflect the heat? I know that that woild basically be making a small oven around it eventually but I think it'd reflect the heat to begin with, and considering the short exposure time, I think it might work.
Darren Jacobson Depends, sometimes a reflector can trap heat inside the system. It's in part a timing differential. However, clamping aerogel mats to the surface can work.
***** Yeah, I kind of figured that might happen.
Gravity I don't know what an aerogel mat is, but what about taping mylar around the connectors?
Darren Jacobson You want to look at the thermal transfer vectors. Mylar is good for reflecting radiative heat, as in from IR. An oven like that will have a lot of convective heat though, and as an aluminized plastic, mylar will likely melt. That's one issue with foil, aluminum itself is thermally conductive. That's one reason it's a prime heatsink material. Aerogel however is an air-pocket insulator, usually ceramic or silica based. You'd want to be using an insulator like that to block the convective vector. It can be surface aluminized as well to block the radiative vector too.
Gravity Right, good point, I was thinking of IR, convective is different though isn't it. Yeah, silica based stuff would probably be good.
tinfoil / aluminium/ aluminum wrap the plastics, its what i do, never had any connector melt :D
Same thing for me - multiple times I've been reballing my old graphic card - worked pretty well untill some day I didn't wrapped it very well, so my plastic connectors melted too. Also the capacitors too need to bee wrapped - they don't like high temperature.
Use your hot air gun to melt/break off the plastic and just use the pins as they stand.
Or do it like I would and hard wire it. What you got to loose?
PIXscotland dignity
+Son of a Zombie hahaha
9:44 the IC pin next to C2102 is not connected ...!?!
O_O
You almost saved me. i was going to do the same mistake!
Good one! Dave! KUDOS
I love how you tend to say "Trap for young players" when you've made a mistake! =D
Brilliant video as always. Keep up the good work!
The element on an oven will typically get very hot and may exceed what the thermostat believes it to be. This is why if you don't preheat your oven, you can burn your pizza. Especially radiative heat might exceed what you are expecting Dynamic temperature profiles on an oven like this is always going to be tricky. Might be better to preheat it and then just throw the whole board in for a short amount of time to approximate the cuve.
But you want your oven to be as hot as possible for pizza, no?
Besides, this is modified oven with controller specifically made for reflowing boards.
Nice video Dave .. but i still think it might be T-con or those chips on flexible ribon cables..you should check if they are not broken..also static discharge could kill it...who knows..
I've wondered on air circulation for toaster ovens if you couldn't put a metal fan blade on a long shaft into there, powered by an external motor going through the side of the toaster oven, that'd mix the air well during the heating cycle, I'd think?
I've heard of people reflow soldering with heat guns, what are your opinions on that particularly since it would be very difficult to control the heat? I suppose you also risk the possibility of physically moving the solder or smaller components with the force of the air. (many PlayStation 3 yellow light remedies use this method)
I have seen those diy ovens having a fan for the cool-down stage. Won't save your connectors of course, and the danger is that you loose heat trough the hole you have to cut for your fan.
Could it work if you put a bit of heat resistant tape on the connectors? This will only help to protect from radiant heat off course.
I very much hope that manage to fix the TV, waiting for a movie showing the success of the repair TV ;)
Are the reflow profiles even so wildly incompatible that the SMD parts must be separated to separate boards?
EEVblog Dave, check gate open voltage on tcon after repairing processor board!
Thanks again for sharing this head-smacking moment, Dave. Always something to learn. As others have said, please don't give up on this TV repair. I'm eager to see the outcome. One thing, is the problem present on all the other inputs/connectors?
Were your bottom element(s) blocked by the board size? This would trick you into leaving the heat on a lot longer on the top element(s).
maybe in a Thermal Oven because if u are experienced, most of the failures are caused by cold joints not transmitting well the electrons after u have used the multimeter and nothing looks wrong.
So, is it safe to assume that the melted right-angle connectors were the only things damaged by the oven, or could there be other components damaged by the heat in less obvious ways?
The RF Receiver? It is trough hole as well. The internal coils can move and the Tuner wont work.
Dave
My guess is that its a JST board-to-wire type. Measure your pin pitch and it's a quick lookup of about 5 to 10 types. If it is a JST then just go and request two samples and as long as you're patient, bob's your uncle.
Kevin
Part 4?
I like these types of videos.
Nice of Dave to continually fall into "the trap for young players" for us ;)
Its messed up but Ive been looking forward to watching him fix this board since he got it and cant wait for another Samsung tv repair video hope he finishes the project.
did you cover them with aluminium foil? it usually works.
a couple powermacs i picked up may need to have its ram sockets reflow, and this isn't helping
just concerned with the wrong things reflowing
Love all your TV videos. Incredible pieces of tech, even these Chinese 4K ones like mine.
Nobody is immune to rookie mistakes,
complacency is way to braking stuff.
Enjoy the videos. Keep them coming!
I will always cover all plastic connectors with aluminum tape the best I can. You never know... A small fan blowing cold air with an Arduino adjusting the PWM to not let it cool off too quick or slow is also not that difficult for the DIYer
Could wrapping in aluminum foil be enough to protect such connectors from damage? That's how some people protect components while reflowing just one, like some huge BGA of, say, PC graphics card. Or is that method only suitable for IR lamp?
At least you can put some new headers on the board. Not saying that it's fixed, but I'd try anyway and see what you get.
Couldn´t you use bluetack to insulate components from heat while reflowing? Maybe some type of clay?
I guess there could be a risk of warping the board, but if the area is small enough, just a couple of connectors, that should be fine though right?
That board threw up. That is weakness leaving the connector. Best of luck Dave
Been there. Done that!
Was the plastic used for the melted connectors different than the ones that didn't melt?🤔 I thought of taking a toaster oven & using it for a m/b pre-heater, but for a whole reflow. Thanks
What about the condensers? That heat doesn't harm them?
Dr. Murphy is always there, remember... lots to remember!
BIG THUMBS UP!!!
Great stuff dave. Thanks!
Hello. Please check if the Tcon equips with a AS15-F IC. It's a very problematic voltage buffer on Tcon boards and it's relatively cheap on ebay. And keep up the good work with the eevblog.
Dave PLEASE PLEASE give the chip on flex panel connectors a wiggle.
Recently I had to replace some SMD components on a board, right next to the 40-pin 1" header.... I used hear gun for SMDs.... and pin header just melted down ;) I realized that too late.
Would using the convection function (if it has one) on the toaster, er, 'reflow,' oven help with hot spots? That's what I've been doing, but with no real proof it actually helps. Just sounded good in my head.
I really hope you can get this TV to work again. I love repair videos, but it's unfortunate that you always have bad luck with either to difficult or too easy problems. Maybe this time :) don't give up!
How come reflow soldering does not damage components that on their datasheet specify absolute maximum temperatures waaaay lower than what is used during reflow? I can understand soldering with a soldering iron, because it's done very quickly, but reflowing takes a very long time in comparison.
I wouldn't count on *all* SMD components to be re-flow resistant. For example some SMD 20mm fuse holders are made to be soldered on by using a sharp tip iron on the side. The worst thing is that even then they begin to melt around the pads. Terrible trap... especially when the board is designed to be used bare and thus the ugliness is visible.
You have to cover that plastic parts with aluminium foil - I do it in my simple cooking oven? and it's okey.
Not sure whether that does the trick. The GND will get hot and the pin to it will melt the plastic. Same for other pins. The foil only helps against the IR radiation.
At the very start of this video, look at the IC in the rear-right - does the pin front-left look like it's lifted off the board?
I like someone who can admit when he made a mistake. Those connectors must be soldered on last.
Just 3d print a pin holder to build sort of a connector !!!. Let Dave (two) make them !!!
I allways reflow with flux and hot air surface mount or not, and last i clean the board with an ultrasonic cleaner. Allways works for me. Interesting video though ;-)
Dave, please please make a video of Tazer or other electroshock device teardown. Maybe someone can send one to Dave though....
good to know. thanks
It did seem heavy handed to melt the entire board, particularly dual sided. Hot air if you must but I wouldn't do that without having located the problem.
And yes it is rather ridiculous how low temperature plastic they use for connectors. They melt with any process you use, it's so stupid.
How did that board make it out of quality inspection
EEVblog cool ass video Dave! As you say Murphy gets us all. You talk about it, but it wasn't 100% clear to me. Had you thought about it before hand what methods could you have employed to protected these thru-hole connectors allowing you to reflow the board? For example perhaps the use of foil, facing the board forward towards the door where your previous video (based on memory) showed some cool spots, etc. Interesting stuff. Thanks.
I would've carved the melted plastic away until the connector fit, unless I had a suitable replacement on hand, that is. But that's me! XD
Why dont they use thermoset plastics?
pretty sure those boards are 5/6 rohs solder...... insane profiles and hours of thermal calibration of the oven....
It's just you who made 2 possible mistakes : you either set the temperature too high, or you just left the board inside for too long. I've succesfully used the oven technique on a graphics card, but the 3rd time i did it i was doing some other stuff too i left it inside for a bit longer and the plastic from the dvi connectors melt a bit, still had no trouble using the card. I haven't been able to repair the issues with the card though, i bought it new and basically crashed most of the time, gave me artifacts and stuff, and even after putting it into the oven, it just shown the same issues. Definitely a chip problem somewhere, not necessarily a solder issue.
It appears that one of your BGA have shifted!