Hello, I’m new to your channel. I like your relaxed approach to repairs because I’ve still got a lot to learn, in this field and it seems to me like many tutorial electronic repair videos are addressed to other professionals - fast talking, jargon spewing “techs” who perhaps, had one too many espressos before filming. Anyhoo, I think you might be able to help me. I was given a Sega Genesis model 2 [VA3] not too long ago - Black screen of death issue. I’ve tried everything I know, on this thing to no avail. The PCB is super clean, no visual anomalies at all. But a few components do get hot, when turned on: The Big IC [35-5700], the 7805, the Ka 2195 d and the MC 68 HC 000 FN8. So far, I’ve replaced the 7805. I changed the biggest cap, nearest to the 7805. Tested the remaining electrolytic caps on the board with an ESR meter [they’re all fine]. Did continuity tests on the DIN connector [video output port] and on the power input jack - all good. Reflowed the common filter [CF1]. Checked the zener diode [D2] out of circuit - it’s ok. Figuring that the KA 2195 D is the encoder chip [RGB] I tested its VCCs at pin 12 and 19, also the 2 volt output at pin 14 - they all checked out. The cartridge connector is in great shape. The crystal on my model IS different though, it’s an SG531PTRS 536931 M, it comes in a black plastic package with four pins and it’s the only device I haven’t really tested because I don’t have an oscilloscope. I’m out of ideas… ANY insights will be greatly appreciated. I’m subscribed to your channel now. Keep making videos and thank you kindly
WOW you really did try a lot. Hmm so I'm assuming that while connected to a monitor the screen DOES go black when you turn it on? I've heard some people ask about the BSOD but they think that that means it just doesn't turn on. Just wanna make sure that console is actually outputting a signal even if its just black. I'm not as familiar with the model 2 and 3's as I am with the model 1's....however..... Do you get a clock pulse at Pin 15 of the 68000 processor? Also you said the 315-5660 IC gets hot. Are we talking smoking hot or just slightly warm? That IC is if I recall correctly is what outputs the 7.6Mhz signal going to Pin 15 of the 68000. If there is no clock at pin 15 check for a clock output at the main oscillator which should be I believe 53.6Mhz. There is also the possibility of a bad solder joint on the 315-5660 SMD IC. I personally hate SMD's LOL. Yes I'm old school. What I'd do is look at the pins under a scope and it wouldn't hurt to throw some flux around the IC and reflow the solder joints with some hot air. I've seen that happen and be the cause of weird issues more times than I can count. If that winds up fixing it, it would be a good idea to pull the IC off, clean the pads and resolder it down. If you don't have a hot air station, you could use a regular iron with a wedge tip. Just be careful to check for shorts due to solder bridging afterwards. You could also reflow the solder on the cartridge connector pins. I found from the constant abuse of carts being slammed in and ripped out the pins will often have cracked joints. Another thing just to get an idea of the general health of the board, (if somethings shorted or not powering up)....is to remove the 7805 and run 5v straight to the board (the third pin) and keep an eye on the current consumption. If it spikes to say 5amps then you have a short. If its only using say 20ma then somethings not getting power. Its sort of a judgement call no exact numbers. However with a single 7805 if there was a short, the heatsink would be smoking hot. BTW I have a few boards that are also dead and you're making me want to pull them out and start working on them LOL. I love this stuff, just not the best at making videos of me fixing them. I wish you the best of luck and hope you can figure it out. Let me know how it goes.
@@Electronicle Hello again, Hey, thanks for replying, I truly appreciate it. Ok, to answer a few of your questions: yes, the console is outputting a signal [I believe] but I get the feeling that it’s not “strong” enough, all I get is a black screen with the occasional flash of white or coloured line, which appear to want to get through… The 35-5660 [in my console, it’s actually a 35-5700] gets warm/hot but not smoking hot, as you say. Now for the stuff I left out of my fist email, as it was already long enough: I have reflowed the pins of the cartridge connector [‘was actually the first thing I did] but it didn’t correct the situation. And yes, I did inject voltage to see how much current this thing was drawing BUT I had not removed the 7805 to do it [perhaps, that was a mistake?]. What I did was: I used my PSU to feed 10 volts to the input pin of the 7805 and the current draw turned out to be +/- 0.5 amps - I don’t think that is very high [please correct me, if I’m wrong]. The only things left for me to try is: the checking for a clock pulse at pin 15 of the 68000, and to confirm that the main x-tal is actually emitting the 53.6 Mhz BUT as I mentioned in my first email, I don’t have an oscilloscope. I’ve already ordered a new oscillator/crystal, as I suspect that, THAT is the issue with this console - I could be wrong… And while I wait for the oscillator, I must find/learn a way to check for clock signals WITHOUT an o-scope. Thanks again for replying and if you have ANY other tricks or suggestion I could try, please let me know. Sorry for these two, rather lengthy emails. Cheers!
Sorry about not getting back to you sooner, just saw your comment. I believe what I used in this video was a ts80. As much as this is supposed to be a backup/portable iron, I find myself using it as my daily. Great iron and runs off USB via quickcharge and/or 9v fast charge standards. I can't say enough good things about these things.
Great skill to have to be able to repair things, instead of throwing them away..
Hello, I’m new to your channel. I like your relaxed approach to repairs because I’ve still got a lot to learn, in this field and it seems to me like many tutorial electronic repair videos are addressed to other professionals - fast talking, jargon spewing “techs” who perhaps, had one too many espressos before filming. Anyhoo, I think you might be able to help me. I was given a Sega Genesis model 2 [VA3] not too long ago - Black screen of death issue. I’ve tried everything I know, on this thing to no avail. The PCB is super clean, no visual anomalies at all. But a few components do get hot, when turned on: The Big IC [35-5700], the 7805, the Ka 2195 d and the MC 68 HC 000 FN8. So far, I’ve replaced the 7805. I changed the biggest cap, nearest to the 7805. Tested the remaining electrolytic caps on the board with an ESR meter [they’re all fine]. Did continuity tests on the DIN connector [video output port] and on the power input jack - all good. Reflowed the common filter [CF1]. Checked the zener diode [D2] out of circuit - it’s ok. Figuring that the KA 2195 D is the encoder chip [RGB] I tested its VCCs at pin 12 and 19, also the 2 volt output at pin 14 - they all checked out. The cartridge connector is in great shape. The crystal on my model IS different though, it’s an SG531PTRS 536931 M, it comes in a black plastic package with four pins and it’s the only device I haven’t really tested because I don’t have an oscilloscope. I’m out of ideas… ANY insights will be greatly appreciated. I’m subscribed to your channel now. Keep making videos and thank you kindly
WOW you really did try a lot. Hmm so I'm assuming that while connected to a monitor the screen DOES go black when you turn it on? I've heard some people ask about the BSOD but they think that that means it just doesn't turn on. Just wanna make sure that console is actually outputting a signal even if its just black. I'm not as familiar with the model 2 and 3's as I am with the model 1's....however.....
Do you get a clock pulse at Pin 15 of the 68000 processor? Also you said the 315-5660 IC gets hot. Are we talking smoking hot or just slightly warm? That IC is if I recall correctly is what outputs the 7.6Mhz signal going to Pin 15 of the 68000. If there is no clock at pin 15 check for a clock output at the main oscillator which should be I believe 53.6Mhz. There is also the possibility of a bad solder joint on the 315-5660 SMD IC. I personally hate SMD's LOL. Yes I'm old school. What I'd do is look at the pins under a scope and it wouldn't hurt to throw some flux around the IC and reflow the solder joints with some hot air. I've seen that happen and be the cause of weird issues more times than I can count. If that winds up fixing it, it would be a good idea to pull the IC off, clean the pads and resolder it down. If you don't have a hot air station, you could use a regular iron with a wedge tip. Just be careful to check for shorts due to solder bridging afterwards. You could also reflow the solder on the cartridge connector pins. I found from the constant abuse of carts being slammed in and ripped out the pins will often have cracked joints.
Another thing just to get an idea of the general health of the board, (if somethings shorted or not powering up)....is to remove the 7805 and run 5v straight to the board (the third pin) and keep an eye on the current consumption. If it spikes to say 5amps then you have a short. If its only using say 20ma then somethings not getting power. Its sort of a judgement call no exact numbers. However with a single 7805 if there was a short, the heatsink would be smoking hot.
BTW I have a few boards that are also dead and you're making me want to pull them out and start working on them LOL. I love this stuff, just not the best at making videos of me fixing them.
I wish you the best of luck and hope you can figure it out. Let me know how it goes.
@@Electronicle Hello again,
Hey, thanks for replying, I truly appreciate it. Ok, to answer a few of your questions: yes, the console is outputting a signal [I believe] but I get the feeling that it’s not “strong” enough, all I get is a black screen with the occasional flash of white or coloured line, which appear to want to get through… The 35-5660 [in my console, it’s actually a 35-5700] gets warm/hot but not smoking hot, as you say. Now for the stuff I left out of my fist email, as it was already long enough: I have reflowed the pins of the cartridge connector [‘was actually the first thing I did] but it didn’t correct the situation. And yes, I did inject voltage to see how much current this thing was drawing BUT I had not removed the 7805 to do it [perhaps, that was a mistake?]. What I did was: I used my PSU to feed 10 volts to the input pin of the 7805 and the current draw turned out to be +/- 0.5 amps - I don’t think that is very high [please correct me, if I’m wrong]. The only things left for me to try is: the checking for a clock pulse at pin 15 of the 68000, and to confirm that the main x-tal is actually emitting the 53.6 Mhz BUT as I mentioned in my first email, I don’t have an oscilloscope. I’ve already ordered a new oscillator/crystal, as I suspect that, THAT is the issue with this console - I could be wrong… And while I wait for the oscillator, I must find/learn a way to check for clock signals WITHOUT an o-scope. Thanks again for replying and if you have ANY other tricks or suggestion I could try, please let me know. Sorry for these two, rather lengthy emails. Cheers!
Nice fix there. It's good to keep these old things running on. Could you share what was that solder gun you used, it looks nice?
Sorry about not getting back to you sooner, just saw your comment. I believe what I used in this video was a ts80. As much as this is supposed to be a backup/portable iron, I find myself using it as my daily. Great iron and runs off USB via quickcharge and/or 9v fast charge standards. I can't say enough good things about these things.
@@Electronicle Thanks for the reply, I'll definitely be picking one up now.