Messages

[Console Repair/Mod Center / Re: PC Engine DUO sound repair]

Look for broken VIAs (small holes in the pcb that connect the upper side with the bottom), mine had no sound because of 2 broken VIAs.

[Console Repair/Mod Center / Re: Help with Cap values for a PC Engine Duo]

Had the same issue with the cap kits I ordered from console5, seems that they had a batch like this,contacted them when I found out so future kits don't have this problem.

[Console Repair/Mod Center / Re: method recommend to not pull up solder pads?]

Cut off the caps with flush cutters. You cut at the bottom of the cap where the ring is. Once the cylinder is off, cut the tips of the metal leads so the plastic base just lifts off. Then you can use your iron and fresh solder to remove the rest of the leads.

Yeah I did that with the Duo I recapped, first time I've recapped a Duo and although some caps looked terrible I didn't pull a single trace (except for an op amp but those are difficult to desolder).

[Console Repair/Mod Center / Re: REPAIR GUIDE - TurboDuo: Sound Fix]

Found one more broken VIA, fixed it and CD audio is back! I almost gave up, thank you Keith for giving me new things to check and keep my hopes up, one more Duo saved

[Console Repair/Mod Center / Re: REPAIR GUIDE - TurboDuo: Sound Fix]

I give it a try yesterday, removed de op amp near the power jack and pulled a trace in the process but I was able to fit in a jump wire so still haven't managed to ruin it 

Checked the caps you mentioned, they seemed ok, not shorted and continuity was there, I thought about reflowing all the op amps and I did, but no improvements, so then I took a break and watched one of the longer duo repair videos on YouTube, the guy actually had problems after recapping and turns out a couple of VIAs had failed on his duo, the VIAs in my duo didn't looked that bad so didn't thought the problem would be there but with nothing else working I gave it a try, took me a while but actually found one that failed the continuity test! It was a small one and it's purpose was to ground one of the underside op amps, fixed it and the cracking is gone! Still no CD sound but I'm glad there's some progress after being stuck for a few days.

I'll check for more VIAs today, thanks for all the help Keith I feel that I'm getting very close 

[Console Repair/Mod Center / Re: Install faster CPU, will it work?]

In theory it should work, no? 10mhz is the max speed that it can run stable, lower speed shouldn't be a problem.

I'm curious about this as a friend had a Killer Instinct Arcade board with a fried CPU, the only replacement that I could find was a faster CPU, he hasn't gone through the repair so I don't know if it indeed works.

[Console Repair/Mod Center / Re: REPAIR GUIDE - TurboDuo: Sound Fix]

crackling means there could possibly be some bad traces to some of the caps, old cap goop in some of the via holes, or goop underneath some of the 4558 Op amps.

I always remove two of the the 4558 op amps every recap job I perform, clean under them really well, and then reinstall. The two to check would be the one closest the the AV jack next to the two 10UF caps and also do the same for the 4558 op amp that is on the bottom side of the board near the Oki5205 chip.

Thanks! I'll try that, let me see if I can get back to it tomorrow, man who would've though cap goop would cause such havoc, so in theory it's shorting the 4558's? haven't checked the one in the underside for shorts now that think of it, I'll try to remove them but if I find it difficult then at least I'll reflow them.

I've cleaned the board thoroughly with water, soap and a soft brush (that's what I do with arcade boards), sadly things didn't improve after it dried, how can you get cap goop out of the vias? A toothpick for the big ones but would that also work in the small ones? I'm also unsure how can it affect the via, is it shorting the via with the stuff around it?

I almost forgot that I took some photos the other day, looking at them I could've done a better job cleaning the flux I used, and some of my solder job looks sloppy, but aside from that is there something that looks troublesome? Here are the pics: https://imgur.com/a/N7sPh

Thanks again Keith!

[Console Repair/Mod Center / Re: REPAIR GUIDE - TurboDuo: Sound Fix]

Hello everyone, new old member here, recently got into modding systems an I ran across a pc engine duo that needed a recap (or so I thought), ordered cap kit from console5 and proceeded to do my first recap job, took me a long time so I was happy when I was done, but unfortunately CD audio didn't work, if I turn the volume up all I hear is static noise and some ocasional cracking, hucard  audio however is loud and clear. The only thing I'd notice is using 4.7uf 50v caps instead of 16 or 25v ones, console5 sent me the wrong ones and apologetic he was going to send me replacements, but since I'm in Mexico I opted to get them locally, so 50v was the only one I could find.

It's been days already since I've been trying to get it working, I've reseated some caps and I'm sure they're all fitted correctly (no shorts, continuity is there to where they're supposed to go, etc), so now mi conclusion is that there must be a damaged component or trace somewhere, after reading all this thread I found out about the audio diagrams Charlie posted, I'm looking at the TurboDuo Audio Multiplexer diagram, since hucard audio works I'm assuming the problem lies at AVC (u505) or at some point before that, am I correct? All 4558 and 4560 ICs that faced upward had normal voltage apparently, well some 4558 had voltage closer to 7 at pin 8 instead of 8 but I think that's normal, one of the voltage divisors is providing 7v so that's got to be the reason (my ac adaptor provides 9v instead of 10).

Sorry for the lengthy post, it has been more challenging than I expected, I welcome any ideas any of you guys might have, hopefull I can get this thing to work, thank you everyone!