Oooh, I had that frozen screen on my Mega-CD. You are the first person I've seen with it and have a fix. However, I think I've buggered mine attempting to recap everything and hitting a trace, but I'll have to go back and have another look at it now
Nice one! Over 10 years ago I bought a MegaCD that was dead on delivery and I made it worse by fiddling around (it just freezes at boot just like yours). This is the first time I've ever heard about being able to do SegaCD tests through the 240p suite and Everdrive! It appears my SegaCD has RAM issues as well so now I know what my next steps are! Thank you! =)
Oh, and also you did replace the RAM chips too right? Original problem with my SegaCD was that it refused to read discs, motor didn't spin. It was so long ago I don't think my troubleshooting methods were optimal but I've always kept it as a spare to see if I can one day get it back up and running fully again.
So first off, awesome video! Glad you could get this one going again! I am currently trying to get my own model 1 sega CD kicking again. I have recapped the power board, the main board and the JVC cd-rom board. All the boards look pretty clean, most of the leaked caps on the main board didn't look all that bad. Most of them had either not leaked, or seemingly only started. But when I test the unit with the 240p test suite (like you are) I am getting failures with programming the memory. Fast check fails on the program ram, and then I get one of each of the following banks tests fail. I tried to remove the memory (as I have more on the way from aliexpress), but my hakko 808 desoldering gun seemed to really struggle with the bottom row of each chip (top row cleans up silly well). I mean bottom as of in, if you have the board facing you, with the memory facing you, it would be the 2nd and 4th row of pins that do not want to come free. The first and third rows seemingly do... I can see daylight easily there. 2nd and 4th you can't... but as you mention the chips are leaning back that way. I don't want to damage this board, but I need to get those chips off. I applied fresh leaded solder and flux before my first desoldering attempt. Did you have your desoldering gun turned up all the way? What air flow and heat was your hot air set at? I realize this was over a year ago... so, yeah. I understand it might be hard to remember that :) Any advice? I'd really love to only attempt this one more time.
Those pins can be a pain. If memory serves me the de-soldering gun was set to about 360c. Once cleared, I used hot air (300c) to heat the pins as I removed the chips but even then it was a pain. After I had to gently clear them with a small craft hand drill. If you know that the ICs are bad, you could cut the chips off with flush cutters, then remove the leftover legs after. The ground on the board is the problem. It soaks up so much heat. The hot air station is your friend. If you can grab the chips with your tweezers and hit the pins on the bottom with the hot air, the pins should come out after a few mins. If you don't have hot air, cutting the legs of the IC might be your best option. Hope that of some help and I hope you manage to get it working.
@@GameTechRefuge Thank you much for the reply! I did manage to get those chips off, though I really had (and have) no way to be sure they were actually the problem. I honestly think they are NOT the problem, but you live and you learn. It was not easy. I cleaned my 808 very well, new filter, added all new fresh solder and turned my heat up a little. I ended up trashing a few bottom side pads, though mostly grounds which are easy enough to bodge in. I too also had to "drill out" some of the holes (and I think this damaged 2 or so of the 4 holes that got the bottom side pads damaged). I have 4 more of those ZIP ram chips in the mail, should have in two weeks or so. I think I have a trace issue, even though this board is remarkably clean in most spots. Aside from a few random vias that don't look too great... there wasn't much notable electrolyte damage near the surface mount caps... I have verified continuity through a lot of the relevant traces, but not all the vias look so great even though they test ok (buzz on the meter in continuity mode anyway). Right now I am making a trace map in excel for the ram chip area, and will try to map out the traces between IC 2 and the sanyo LSI chip and the other larger quad flat pack.... so that I can double check those with my meter. I'm thinking I'll end up needing to repair a few traces with magnet wire. Loooootts of hours so far into trying to save this one. Hopefully, I get it fixed! Thanks!
It can be tough tracing out everything but worth it. Good call on the excel sheet, neat idea. Take care with schematics online, and make sure it matches. I spent a long time head scratching only to figure out later that I was looking at the wrong main rev drawings :) (The connectivity is the same just the IC numbering was off ) Electrolyte damage is funny. Visual evidence doesn't always mean much. You can have a board that looks clean but has more damage to traces and vias than one that looks like a fish shop :) . My guess is that allot of it comes down to the temperature and humidity of the place it was stored. Without magnification and some super small/sharp probes on the meter, it can be really tough to find the breaks. I went out and got (€50) precision probes after battling one specific SEGA CD board. Be very careful around IC2 ( MEGA-CD ENGINE IC , 315-5548 ). I've had some legs of that detach from their pads due to corrosion. Even had traces separate from the pads. Nasty stuff. Can be really easy to damage the legs or have a pad float away during rework. I'm considering just lifting IC2 off altogether in future repairs. Fixing the pads and traces and putting it back on with just hot air, try not use the iron much. I need more practice with fine pitch chips like this first. Hope the new chips do the trick and if there's any other help/advice I can give you, don't hesitate to ask.
the first background image seen in the sega cd logo is stored in genesis vram as far as i know. the sega cd vram is used for the 2 scaling and rotating graphics. my cd unit boots up but has these 2 graphics distorted but background image is ok. i even can not boot any game but plays audio cd fine. i got distorted ascii text when i execute options (backup ram menu).
Hi I have a Sega cd1 I’m repairing for my young nephew and it doesn’t play background music. It doesn’t play music cds either but it does show that it’s reading them. I have had all the caps changed by a reputable tech. I also changed the belt and laser. I’m at the end of very very limited knowledge. Any clues? Thanks
I got them from a seller on Ali Express. The TC511664BZ-80 ZIP can be hard to find from western sources. I would order double the amount you need, so you have spares. Just in case.
Dislike ? Thumbs up here.
Great video Dermot, looking forward to part 2. oh, and thanks for the shout-out it's much appreciated.
Oooh, I had that frozen screen on my Mega-CD. You are the first person I've seen with it and have a fix. However, I think I've buggered mine attempting to recap everything and hitting a trace, but I'll have to go back and have another look at it now
Nice one! Over 10 years ago I bought a MegaCD that was dead on delivery and I made it worse by fiddling around (it just freezes at boot just like yours). This is the first time I've ever heard about being able to do SegaCD tests through the 240p suite and Everdrive! It appears my SegaCD has RAM issues as well so now I know what my next steps are! Thank you! =)
Oh, and also you did replace the RAM chips too right?
Original problem with my SegaCD was that it refused to read discs, motor didn't spin. It was so long ago I don't think my troubleshooting methods were optimal but I've always kept it as a spare to see if I can one day get it back up and running fully again.
Why I haven't found this video until now I don't know. Exactly what is wrong with my Model 2! Now to find the memory modules! Thank you!!
So first off, awesome video! Glad you could get this one going again!
I am currently trying to get my own model 1 sega CD kicking again. I have recapped the power board, the main board and the JVC cd-rom board.
All the boards look pretty clean, most of the leaked caps on the main board didn't look all that bad. Most of them had either not leaked, or seemingly only started.
But when I test the unit with the 240p test suite (like you are) I am getting failures with programming the memory. Fast check fails on the program ram, and then I get one of each of the following banks tests fail.
I tried to remove the memory (as I have more on the way from aliexpress), but my hakko 808 desoldering gun seemed to really struggle with the bottom row of each chip (top row cleans up silly well). I mean bottom as of in, if you have the board facing you, with the memory facing you, it would be the 2nd and 4th row of pins that do not want to come free. The first and third rows seemingly do... I can see daylight easily there. 2nd and 4th you can't... but as you mention the chips are leaning back that way.
I don't want to damage this board, but I need to get those chips off. I applied fresh leaded solder and flux before my first desoldering attempt. Did you have your desoldering gun turned up all the way? What air flow and heat was your hot air set at? I realize this was over a year ago... so, yeah. I understand it might be hard to remember that :)
Any advice? I'd really love to only attempt this one more time.
Those pins can be a pain. If memory serves me the de-soldering gun was set to about 360c. Once cleared, I used hot air (300c) to heat the pins as I removed the chips but even then it was a pain. After I had to gently clear them with a small craft hand drill. If you know that the ICs are bad, you could cut the chips off with flush cutters, then remove the leftover legs after. The ground on the board is the problem. It soaks up so much heat. The hot air station is your friend. If you can grab the chips with your tweezers and hit the pins on the bottom with the hot air, the pins should come out after a few mins. If you don't have hot air, cutting the legs of the IC might be your best option. Hope that of some help and I hope you manage to get it working.
@@GameTechRefuge Thank you much for the reply!
I did manage to get those chips off, though I really had (and have) no way to be sure they were actually the problem. I honestly think they are NOT the problem, but you live and you learn.
It was not easy. I cleaned my 808 very well, new filter, added all new fresh solder and turned my heat up a little. I ended up trashing a few bottom side pads, though mostly grounds which are easy enough to bodge in. I too also had to "drill out" some of the holes (and I think this damaged 2 or so of the 4 holes that got the bottom side pads damaged).
I have 4 more of those ZIP ram chips in the mail, should have in two weeks or so.
I think I have a trace issue, even though this board is remarkably clean in most spots. Aside from a few random vias that don't look too great... there wasn't much notable electrolyte damage near the surface mount caps...
I have verified continuity through a lot of the relevant traces, but not all the vias look so great even though they test ok (buzz on the meter in continuity mode anyway).
Right now I am making a trace map in excel for the ram chip area, and will try to map out the traces between IC 2 and the sanyo LSI chip and the other larger quad flat pack.... so that I can double check those with my meter.
I'm thinking I'll end up needing to repair a few traces with magnet wire.
Loooootts of hours so far into trying to save this one. Hopefully, I get it fixed!
Thanks!
It can be tough tracing out everything but worth it. Good call on the excel sheet, neat idea. Take care with schematics online, and make sure it matches. I spent a long time head scratching only to figure out later that I was looking at the wrong main rev drawings :) (The connectivity is the same just the IC numbering was off )
Electrolyte damage is funny. Visual evidence doesn't always mean much. You can have a board that looks clean but has more damage to traces and vias than one that looks like a fish shop :) .
My guess is that allot of it comes down to the temperature and humidity of the place it was stored.
Without magnification and some super small/sharp probes on the meter, it can be really tough to find the breaks. I went out and got (€50) precision probes after battling one specific SEGA CD board.
Be very careful around IC2 ( MEGA-CD ENGINE IC , 315-5548 ). I've had some legs of that detach from their pads due to corrosion. Even had traces separate from the pads. Nasty stuff. Can be really easy to damage the legs or have a pad float away during rework.
I'm considering just lifting IC2 off altogether in future repairs. Fixing the pads and traces and putting it back on with just hot air, try not use the iron much. I need more practice with fine pitch chips like this first.
Hope the new chips do the trick and if there's any other help/advice I can give you, don't hesitate to ask.
the first background image seen in the sega cd logo is stored in genesis vram as far as i know. the sega cd vram is used for the 2 scaling and rotating graphics.
my cd unit boots up but has these 2 graphics distorted but background image is ok.
i even can not boot any game but plays audio cd fine.
i got distorted ascii text when i execute options (backup ram menu).
Is that a PAL CRT you are using? I'm wondering if the 50Hz display is causing the flickering effect in the 60Hz TH-cam video.
Great video =D Looking forward to part 2! Note: faster will work (as a mismatched pair), slower however might be a problem.
Hi I have a Sega cd1 I’m repairing for my young nephew and it doesn’t play background music. It doesn’t play music cds either but it does show that it’s reading them. I have had all the caps changed by a reputable tech. I also changed the belt and laser. I’m at the end of very very limited knowledge. Any clues? Thanks
Very interesting video. I’m trying to repair 2 Mega CD1 from Japan. Very difficult task…
Thank you so much for this video, this was the exact problem I was having
O meu mega cd 1 não sai da tela de bios. Alguma sugestão! Ótimo vídeo
Where did you get the memory chips?
I got them from a seller on Ali Express. The TC511664BZ-80 ZIP can be hard to find from western sources. I would order double the amount you need, so you have spares. Just in case.