Hantarex Polo 25" Flyback / HOT Replacement - Mortal Kombat Restore Part #5
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- Опубликовано: 12 ноя 2016
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In this video we will change the flyback in our Hantarex Polo 25" monitor. We'll also test the HOT. This monitor is currently in HV shutdown and we've already done a cap kit. Mortal Kombat restore Part #5 
Игры
I don't want to see you struggle, but if you struggle I want to see it. it's those tricky moments shared can help us feel we are not alone making mistakes. Most people want you to only see their best side and will edit out errors, but you don't, and I realise that's what I love about you John, your honesty.
Thanks, Andy! :)
Great comment.
The errors really do help. I've learned patience through mistakes, you do a great job of demonstrating errors with grace! It definitely serves as a great model!
This is more suspenseful than most thrillers. Every time the monitor should turn on I'm sitting going C'mon picture!
Hey John, don't beat yourself up mate, you've always showed the good, bad and the ugly side of arcade repair and that's what we like so much about the videos and why we watch every episode. I think you've been a bit unlucky, a bit like I am so it's more real to me.
Keep up the good work!
John, I'm watching you bend that extra leg and I'm thinking "AHHH Its gonna snap off ! For the love God STOP!!" lol :)
Seriously, thanks for making this video-series. Saving games like TMNT & MKII is great to see.
Chuck Smith I was yelling at the screen too!
Glad to see you try out a chisel/screwdriver tip. You'll really start to appreciate the thermal capacity of a chisel tip as you get used to using it.
electronicsnerd
I've been trying to champion the chisel tip for years. lol
I use a 2.5mm chisel on my Metcal station, and it serves me well for both the tiniest 0402 SMD components, and normal through-hole stuff.
Those pointy conical tips seem to come with so many irons / stations, and are half the reason people seem to have so much trouble.
I started off with the big shovel tip irons when I was about ten, and they are almost as bad for generally frying the boards and lifting pads / traces etc.
Thermal capacity of the iron itself is another issue - many beginners think that because they have a 700-degree F 60W iron that it will necessarily work well on large ground planes or heatsinks.
That mainly depends on the ability of the iron or station to supply the heat fast enough, and that's a totally separate thing to the maximum temp, of course. ;)
Can't Wait For The Mini NES Video!
Polo's can be a huge PITA. I feel your pain there John.
I want to see John rage out and just slam the monitor on the ground
But, it's more fun to take it out to the gun range and pump the sucker full of holes until it's a billion pieces.
Alas...this channel is about saving the troubled tech. Not caving in to frustration and satisfaction for primitive destruction.
hahaa dudes got more patience than me thats for sure!
Great video, John. Glad you didn't have too much trouble seating the flyback! LOL Some flux for de soldering really helps right? At least when you get back to it, there will be nothing else left to replace lol! : ) Thanks and can't wait to see it up and running.
23:40 "I'm heating this up... and wiggling it" Man I have such a dirty mind lol
You should do a live stream edition of the show where people can interact with you and brainstorm the issues that you run into together...wonder if that could even work..
when soldering large parts that use alot of heat, you will need a thick tip so it dosent lose all its heat while soldering
Wonderful idea to do a side-by-side with the Nintendo Classic. And, you were lucky to score one. What I've been hearing is that those are in really limited supply. Many stores were said to have gotten five. Alas, your choice got ten. And my local Wally's got zero. (I'm not paying e-bay scalper prices, neither.) These things will probably lose that 'rare' status, once Christmas has passed.
Of what I've seen on-line, they play and sound like the originals. Only it's got the high definition going on. And the much needed save points. (SMB 3 always needed that.) Plus, support for the Wii Pro controllers. (Longer wire.) About the only minus is the included controller's wire is way too short. Sure. The system is tiny. But, the wire length didn't have to reflect that.
On the video side, I thought the microphone picked up a tiny 'snap' when you turned it on after replacing the flyback. Was expecting it to be that tick tattler. But, the mic only recorded one snap. (Probably not helpful in the least. I know...)
Johns Monitors Reviews & Tech :)
awesome shirt
I know that frustration. Drives you insane.
Phoenixarcade is worth mentioning for art. Darin does nice stuff.
Yeah, but Rich @ Thisoldgame makes most or a lot of it.
At 09:45 you're getting caught out the same way i did on the same chassis haha. HOT blowing is common on these with no lopt problems.
Fun fact: high impact was the game that MK toasty came from. It was a taught Dan Forden would use on Ed Boon.
The Zelda clone is called Oceanhorn. It's a fantastic game!
John, still think it's a good idea you showing discharging a monitor. Never know if you got a first time viewer. Important safety tip.
Horizon Chase mentioned here: 01:04:11 is an Outrun clone. Pretty nice.
FYI, mica is a mineral found in thin flexible sheets, not a plastic.
Interesting!
John's Arcade Game Reviews & Tech
That "Ground" connection on the old flyback is likely just for mechanical support. It makes sense just to connect it to ground on the original one anyway, but it's not an electrical requirement.
The ground pin on the focus / screen pot is absolutely definitely required though. :p
The pots are literally just set up as a voltage divider...
(where "G2" is the "screen" voltage.)...
www.electro-tech-online.com/attachments/image-jpg.94172/
You can see how the flyback is normally connected to the HOT as well.
"+ VCC" on the diagram is the "B+" supply that goes to the primary winding of the flyback. The other end / pin of the primay winding goes to the Collector of the HOT.
(On those TO247 transistor packages, the middle pin is very often connected to the uninsulated tab, but not always. On the NPN types, the middle leg is quite often the Collected, but again, not always, so the datasheet should really be checked, even just when replacing a part.)
The Emitter is normally connected to Ground, so you can imagine that when the HOT gets a pulse on the Base pin, it switches on, and allows current to flow from the B+ supply, through the primary winding, through the Collector and down to Ground via the Emitter. ;)
With the HOT shorted directly to the chassis ground, it could possibly have damaged the old flyback because the current will be permanently supplied to the primary. Almost all modern monitors normally have current-limiting and other protections on the B+ supply though.
IIRC, part of the reason it's called a flyback transformer is that the bulk of the HV pulse actually happens after the HOT is switched OFF. This is because the field inside the flyback collapses, and induces current in the secondary windings.
It's also because the horizontal scanning of the beam obviously correlates to the pulse on the flyback.
See "usage and operation". It has a good explanation of the current pulse on the primary winding vs the secondaries...
en.m.wikipedia.org/wiki/Flyback_transformer
John's Arcade Game Reviews & Tech
I thought you'd get that flyback in easily after straightening a few pins. lol
tbh, I never had any issues with fitting the flybacks. Just need to line the pins up, see which ones might not be on target, bend them carefully with the pliers, then try again.
Need to be careful not to snap that ground pin on the pots though.
40:40 - you will often find that most of the pins on the flyback seem to test as "grounded", but you are basically just measuring the windings themselves.
Going back to that schematic in my previous post, you'll see that there are multiple other secondary windings for supplying voltage to other parts of the monitor, like the RGB driver transistors on the neck board etc.
In many cases, the other end of the secondary windings will be connected directly to the ground plane, and the windings will have a very low resistance of only a couple of Ohms (or far less).
So, it's one of the pains of transformers that you can't always use continuity around them.
Some of the better meters can do really accurate low-Ohms readings, but even then it's a PITA to figure out what is true ground and what isn't. lol
btw, it's better to always twist the strands of wires together before tinning them, and also always add a dab of fresh solder to the joint you will be attaching the wire to. ;)
42:20 - the Focus wire almost always goes directly into the CRT socket, as it's quite a high voltage, so it gives it extra insulation, but there's also a spark gap in there for if the voltage gets too high. The CRT sockets normally un-clip, but some are a pain, and the clips can be brittle on the older ones.
I feel your frustration on these vids btw, but replacing parts without being able to properly diag the fault or test the old parts is unfortunately going to result in lots of frustration.
It's quite likely that the old flyback was still working too. They are usually a tad more sturdy than people might think, and it's quite easy to build a test circuit to make sure they don't have a dead short on the primary or secondary.
I want to visit some day and help fix this stuff. lol
I miss working on CRTs, and it still amazes me what a genius invention they are.
Even more amazing when you realise what the different voltages do inside the electron gun and tube. ;)
The heater in the neck is there to "boil off" electrons, and basically create a small cloud of them.
(there is also a Cathode plate just after the heater.)
The G1 voltage goes to the "Control grid", which is the first stage which attracts the electrons, and starts them accelerating towards the front of the tube...
The G1 voltage is what is driven by the RGB transistors on the neck board - Because the electrons are negatively charged, the more positive the G1 voltage, the more electrons are attracted to that plate, and the DARKER the screen.
So the voltages on the output of the RGB drive transistors are actually inverted compared to the brightness of the incoming video signal. (this was news to me when I was first learning. lol)
The G2, or "screen" voltage is fixed, and is the next grid along, and helps accelerate the electrons faster still (the number of electrons in the bunch being affected depending on the voltage on G1, of course).
The focus voltage is G3, and the voltage is actually lower (more negative) than the G2 voltage, IIRC?
The arrangement of the focus grid(s) means it either repels or attracts the electron beam, so either squishing it into a tighter beam, or expanding it.
I guess the exact voltage setting of the focus pot depends on the initial width of the beam, the distance from the neck to the front of the tube, and the relative voltage of G2.
Lots more info here...
lateblt.tripod.com/bit71.txt
You seem to be having a lot of bad luck with monitors. but on the bright side you will be a master at monitor repair by the end of it all.
For a complete art package, check out Szabo's Arcades here on RUclips.com. He does custom artwork that suits your needs. He specialized in repros and of course custom MAME artwork. He's an amazing graphic artist. John mentioned him at 01:07:54.
it amazes me the hardware that went into arcade machines, seemed to be full of components wires and parts endless stuff. now it's all nano technology. Will the tmnt and mortal k finished projects be going into basement ?
Hey I got a polo in my Time crisis and one day the screen shrank, like went from a 25" to a 21". The height I can adjust but the width coil does absolutely nothing, any idea on either how to fix it or where to buy a width coil for a polo? Thanks love the show, rebuilt a MK2 last year with mixed results, the side art and sound board gave me issues.
Your way more patient then me, if it were me it would have gone out the window by now lol
and do you have any interest in the Atomiswave or naomi based hardware??
yeah, scanlines on all 60 John ::D
31:40 Maybe you can insert the flyback through the back (the reverse) of the board first, to align the pins.
You really need a Moppet!
Surprised you were able to get one of the nes classics.
Here's what I do now... Skip to the end. Is it fixed? Yes, go back to the beginning and watch. No, wait until the next video comes out. LOL! Just kidding John! Hope you get this sucker fixed soon!
Hey John, I got a Video Poker machine with a monitor that won't turn on (you probably won't want to hear it haha) But Your videos are very informative, and I'm looking for bad caps now, have you ever worked on a video poker machine before?
I forgot to Sub, I did now... =)
You should order transistors in packs of 10 :) Did you drop and crack your Hakko?
Where did you get that Nintendo Tech Support shirt from if you don't mind me asking? I hope a brand new hot fixes the issue.
Quick question???!! MK2 cuts on and plays but after 10 mins a hotspot comes up and turns off. When it cools off it will turn on again???
Just the tip 😂
hi guys, just a stupid question that i have, can i use a tube smaller than the one it came with my hantarex ? i have polo 28" i want to use a 25" please help thx
if you have problem in bu2520 (polo/2) and you replace it but when you give power it works for 3 seconds and then you have the ssme problem βθ2520 short circuited what else can you check?
is the soldering iron tip pre tinned
Hey John, did you see the spark at 17:25 right near the power connection for the monitor ?
Weird. I see that now. Odd.
Are you talking about the thing at 17:28? Right after he said "I heard some kind of tick sound"? I think that could be dust. It didn't look like a spark to me.
I think you're right. It's dust. You can see it fly off the screen
Right when he says that's, you can hear a tick or spark, along with the flash.
Could just be dust, hard to tell.
Line up the pins with the old one ?
damnmit i think i sent my email to the wrong one lol i was so used to your original email
idea: nes mini classic donkey Kong 300,000 challenge?
I came from the future... don´t move that video test jumper..
Lol.
If that Polo 25" is a medium resolution monitor then it won't ever sync trying to connect the standard-res signal ,I've had a couple Polos I worked on recently that I needed to do very extensive touch up work on solder joints, on one I had a block cap that was half out, the other had solder joints bad on a transformer and something else (caused it to not power up at all, there was no ticking there). another chassis actually formed some major cracks under the flyback, had to patch about 8 traces with wire on that one. they're a bitch, and they're very fragile, so be careful.
check everything. if it looks suspect, get your meter out and check the continuity. those broken traces I thought were just a scratch along the bottom, and they were broken.,,,
+scroeffie it is standard res.
Well, didn't get that monitor fixed but the NES Classic Edition video is probably going to be a fun way to unwind from it. Though I do really hope you didn't pay more then the MSRP for it. Ah good, you hopefully didn't at Target.
Nope, I bought it at Target on day one. Normal price.
You lucked out big time John, struck while the iron was hot!
where did you get those jumper wires with the alligator clips?
ebay!
found 'em at Radio Shack too John!
my 6100 spot kill is on, Mario bros is starting to collapse at the top and I have a 4900 acting funny also! can we move on please lmfao and yes I'm going to try Kellogg for parts. Oh I got pics for proof also!!!!!
An actual Sunday video?
Austin LaPlante ¥€$
What happened, John: did you get your HOT too hot? :D
Shouldn't you ground the monitor chassis to something if it's just sitting on your bench? Back when I was a tech we had static pads where we could ground off equipment. I just wonder where the charge would go if the monitor is just sitting on the desk. Maybe I am totally wrong, just wondering
Bob Marley so long as the bench isnt conductive you are fine. Most of us monitor techs hang the chassis off the back and upside down to probe them with a scope.
Read this. It talks about what you are doing when shorting the tube to frame.: www.andysarcade.net/personal/tech/discharging.txt
John's Arcade Game Reviews & Tech
While most of that guide is fair enough, if you really want to protect the HV diode on all flybacks (because most of them will have a diode - they output DC pulses, which get smoothed by the CRT capacitance itself), you should still ideally discharge all CRTs via say a 1K power resistor, just to be sure.
The idea is that you are discharging the capacitance on the tube itself though, but you can get a charge on the flyback side too (some might have an internal HV cap), so there's still a slight risk of damage if you short the anode to ground directly.
Also, gloves and extra insulation on the screwdriver and wires aren't stupid ideas either - if you've been repairing them for years, then fine, but, as you found out, if the croc clip falls off the chassis, or the wire looses contact with the screwdriver, the arc can still jump to you thumb.
Guess how I also found that out once. lol
John's Arcade Game Reviews & Tech
54:30 - the HOT is actually LESS likely to die if the Collector is directly shorted to the chassis ground. ;)
If you look at that schematic I posted before, you can see why...
www.electro-tech-online.com/attachments/image-jpg.94172/
With the Collector (top pin on the diagram) shorted to ground, it will just be doing what the transistor normally does when it switches on, ie. essentially connecting one end of the flyback primary winding to ground.
In that "common emitter" style configuration, the transistor can only ever pull that pin on the flyback down to ground.
(the current is only supplied to the flyback at the other end of the primary winding, ie. on a different pin.)
The only other problem is that shorting across the collector and emitter means that the flyback will be getting constant current from B+ through the winding. Well, until the PSU hopefully shuts down.
The pulses to the HOT (and thus through the flyback primary) are normally quite short, so the average current isn't that high. But, if the HOT collector is shorted to Ground, the PSU should detect the over-current, then shut down rapidly, hence the ticking.
I think you're probably right though - the old flyback might have had a dead short on the primary, and that's why the original HOT failed, and also why the new one did when it was tested briefly.
(you can get shorts between different windings too, and that's never a good thing. lol)
Haha!
* "Let's restore us some MORTAL KOMBAT!"
* "I don't like the fighting games."
Huhh? Hehe....
just drill chassis
13
Move on to the pinball
#SOON
#yes #arcadesarefunbutiwanttoseehowyoufixanEMpinball
Luzur ME TOO
Are you familar with this game John? Midway - Space Encounters The cab looks great!! instagram.com/p/BMwzbicgECh
Yeah, for sure! It's super cool. A lot like the trench in Star Wars.
Ughh, did you miss my message that "Soldapullt" is not pronounced with "-pull it," but just "-PULT" (as in "catapult")? Come on, John, you took other people's pronunciation keys seriously (for example, with Taito). Can't you take mine too?
I've had better luck with desoldering braid than any tool like a Soldapullt. I know you don't like braid though.
Maxx Fordham He did start saying it correctly for a couple episodes a while back, then he reverted to "pull-it" haha
Heheh, give me the links and times then, so I can hear them.
I don't know if I could ever find it again.. Might have been during the jump bug restore
Haha, oh, well that's way back there!
Just worked on the same monitor, The flyback and cap kit I installed worked perfectly! Thank you iankellogg.com
ugh thats dirty.......Effin Mica's
OH FOR THE LOVE OF GOD! this is worse than Tempest. Check the diodes around the HOT again. i'm going to Grab the schematics and figure out what the hell is going on.
Found something.....that is not the original CRT that goes with the PCB and neckboard
s445.photobucket.com/user/WERY_The_Duce_A/media/4_Chassiotubverblick.jpg.html
just get a new monitor cause I don't think you will bring it back to life
+Brian DuBose I never give up. :) We will get it!
I dislike this monitor I have many problems with the polo I made the mistake of bringing it back to life and almosr gave up on it.good luck