Irem PCBs and leaking capacitors - M92/M107
Irem PCBs and leaking capacitors - M92/M107
Just covered this on my blog, it deserves a heads up though.
If you have any M92 or M107 games with brown capacitors, just replace them - they're going to leak at some point and it's better to do it now than later when the damage is done, I'm seeing this problem all the time now. In fact theres a Japanese Undercover Cops on Yahoo auctions right now, it's already well past 30k yen, but the unused solder pads for the heatsink are ... green. That thing is swimming in electrolyte, that's exactly what happens.
http://blog.system11.org/?p=1038
I have not seen any instances of the green variant leaking. Perhaps they do, but I've never seen it. I've seen it on all bar one board using the brown caps now.
If you have any M92 or M107 games with brown capacitors, just replace them - they're going to leak at some point and it's better to do it now than later when the damage is done, I'm seeing this problem all the time now. In fact theres a Japanese Undercover Cops on Yahoo auctions right now, it's already well past 30k yen, but the unused solder pads for the heatsink are ... green. That thing is swimming in electrolyte, that's exactly what happens.
http://blog.system11.org/?p=1038
I have not seen any instances of the green variant leaking. Perhaps they do, but I've never seen it. I've seen it on all bar one board using the brown caps now.
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Re: Irem PCBs and leaking capacitors - M92/M107
Cool, I'll check this out. Thanks for the heads-up 

Re: Irem PCBs and leaking capacitors - M92/M107
We can add M97 to the list of affected boards. Same as before - brown ELNA caps.
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Re: Irem PCBs and leaking capacitors - M92/M107
WOW, thanks for the heads up, i will check mine.
Are those caps on the bottom or upper board?
Are those caps on the bottom or upper board?
Re: Irem PCBs and leaking capacitors - M92/M107
I just checked mine and they both have green caps on those locations. The problem is only with the brown ones?
At least they all look in great condition for now...
At least they all look in great condition for now...
Re: Irem PCBs and leaking capacitors - M92/M107
I've only seen the brown leak so far, if someone sees green doing it please post! So far I've only seen one PCB with brown that didn't have at least one leaking or some already replaced.
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Re: Irem PCBs and leaking capacitors - M92/M107
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Last edited by cfx on Thu May 29, 2025 7:43 am, edited 1 time in total.
Re: Irem PCBs and leaking capacitors - M92/M107
Appreciate the detailed post including the cap values and locations system11. Do you have any before/after pics? I have a huge list of boards I'll have to look over, and will only really make time if any look like they are starting to leak.
Re: Irem PCBs and leaking capacitors - M92/M107
All this time I hadn't yet seen an In The Hunt actually leaking.
Now I have - 3 bad ones on this one from Japan. Every game with brown ELNAs is suspect, this was the final confirmation. It's not even a bad batch, it's just a shitty component.
Now I have - 3 bad ones on this one from Japan. Every game with brown ELNAs is suspect, this was the final confirmation. It's not even a bad batch, it's just a shitty component.
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Re: Irem PCBs and leaking capacitors - M92/M107
Interestingly the Elna caps in my X68000 XVI aren't leaking, but they do seem to be the cause of PSU failure there. Guess the Elna caps from that time period don't hold up.
Re: Irem PCBs and leaking capacitors - M92/M107
Interestingly the green ones on the same board types don't seem to suffer.
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Re: Irem PCBs and leaking capacitors - M92/M107
Got a picture of what you mean by 'brown capacitors'? I have a couple IREM boards, but unsure what you're talking about exactly because I'm a bit color blind =/.
Re: Irem PCBs and leaking capacitors - M92/M107
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Re: Irem PCBs and leaking capacitors - M92/M107
Perfect, thanks.
Re: Irem PCBs and leaking capacitors - M92/M107
Can add M99 (M97 variation) to the list of affected boards.
Re: Irem PCBs and leaking capacitors - M92/M107
M99 ? Interesting, it's not listed on System16.
What game do you have on it ?
What game do you have on it ?
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Re: Irem PCBs and leaking capacitors - M92/M107
Hey could you post a close up of the sound section of the board please? I'm pretty sure M99 is identical to M97 but I'd like to check before saying my M97 cap chart works for 99 too.
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Re: Irem PCBs and leaking capacitors - M92/M107
Yes, will do it.system11 wrote:Hey could you post a close up of the sound section of the board please? I'm pretty sure M99 is identical to M97 but I'd like to check before saying my M97 cap chart works for 99 too.
M97 and M99 are different but really close, I will check with a M97 if the caps in the sound section are the same.
Re: Irem PCBs and leaking capacitors - M92/M107
M97 and M99 are using the same 9 caps.
M97:

M99:

In fact the main difference between the 2 PCB is this IREM component on the M99:

http://git.redump.net/mame/plain/src/mame/drivers/m90.c
Need to take care of this M99 now ...
M97:

M99:

In fact the main difference between the 2 PCB is this IREM component on the M99:

http://git.redump.net/mame/plain/src/mame/drivers/m90.c
Need to take care of this M99 now ...
Last edited by ifog on Sun Jan 04, 2015 8:49 am, edited 1 time in total.
Re: Irem PCBs and leaking capacitors - M92/M107
The plague continues... I hope collectors are checking their PCBs.
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Re: Irem PCBs and leaking capacitors - M92/M107
I recently saw this that my undercover cops pcb is in pretty bad shape!
First I didn't noticed and tested the game straight away. The Sound was bad an even the screen was "wavey"
So is this the result of the leaking capacitors? Would replacing the brown caps do the job or do I have replace even more compontens of the board?
You can clearly see that the damamge has already begun. How bad actually is the condition of this board?
heat sink greenish at bottom. should'nt affect any thing on the board operation?
heat sink again
cap near the soundchip. this one is responsible for the sound? Should I replace the R219 too or will cleanig help too?
again the C236 leaks pretty baddly
what about all those greenish R2... components ? do they disturb the operation?
what could be responsible for the bad and wavey graphics?
And now the R-TYPE LEO Board luckily still "calm before the storm"
Soundchip cap C236 as it should be
board still in good condition

First I didn't noticed and tested the game straight away. The Sound was bad an even the screen was "wavey"
So is this the result of the leaking capacitors? Would replacing the brown caps do the job or do I have replace even more compontens of the board?
You can clearly see that the damamge has already begun. How bad actually is the condition of this board?
heat sink greenish at bottom. should'nt affect any thing on the board operation?
Spoiler

Spoiler

Spoiler

Spoiler

Spoiler

And now the R-TYPE LEO Board luckily still "calm before the storm"
Spoiler

Spoiler

Spoiler

Re: Irem PCBs and leaking capacitors - M92/M107
Yep, Undercover Cops seems to suffer most commonly of all...
You need to replace all those brown capacitors. First job is to remove them all (I cut the legs with micro pliers), clean the sound area with isopropanol or similar, and then order the replacements. The resistors don't look great but they're better than mine were, if the outer casing hasn't started breaking away you can probably get away with leaving them there. They could be tidied up with a fibreglass pen (be careful with these, do it in the open and wear a mask, brush down the pcb with a paintbrush or similar after use). You're lucky 236 hasn't managed to corrode the surface mount chip yet. Probably not related to wavy lines.
You need to replace all those brown capacitors. First job is to remove them all (I cut the legs with micro pliers), clean the sound area with isopropanol or similar, and then order the replacements. The resistors don't look great but they're better than mine were, if the outer casing hasn't started breaking away you can probably get away with leaving them there. They could be tidied up with a fibreglass pen (be careful with these, do it in the open and wear a mask, brush down the pcb with a paintbrush or similar after use). You're lucky 236 hasn't managed to corrode the surface mount chip yet. Probably not related to wavy lines.
System11's random blog, with things - and stuff!
http://blog.system11.org
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Re: Irem PCBs and leaking capacitors - M92/M107
ok thanks but where could the wavy lines come from. gotta has something to do with the graphic chip. where is it located on the board?
Re: Irem PCBs and leaking capacitors - M92/M107
My suggestion:RuffNEC wrote:ok thanks but where could the wavy lines come from. gotta has something to do with the graphic chip. where is it located on the board?
Don't bother yet with the graphic problem.
Right now you need to remove all the capacitors and clean the PCB.
Later you can solder new capacitors and retest the PCB to check what kind of problem remain.
Looks like someone alreay change a capacitor on your R-TYPE Leo.
Re: Irem PCBs and leaking capacitors - M92/M107
I've cutted the caps on my in the hunt and ucc board. as the LEO Board is still fine I leave them a bit so I can still play with it.
yes that green cap looks like changed already on the r-type leo board
yes that green cap looks like changed already on the r-type leo board

Re: Irem PCBs and leaking capacitors - M92/M107
btw anyone has checked their XEXEX PCB ?
I have a feeling that the Sound caps are leaking too
I have a feeling that the Sound caps are leaking too
Re: Irem PCBs and leaking capacitors - M92/M107
Known problem - all Konami boards with that sound custom need to be recapped too - but the job is much more difficult. The guy who runs Jamma Nation X sells cap kits.
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Re: Irem PCBs and leaking capacitors - M92/M107
what kind of caps would you buy? High quality and expensive or go with the affordable ones on eBay?
Re: Irem PCBs and leaking capacitors - M92/M107
High quality and expensive you want the repair to last.RuffNEC wrote:what kind of caps would you buy? High quality and expensive or go with the affordable ones on eBay?
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