PC engine Duo not reading disks issue help

Neogeoman106st

Crossed Swords Squire
Joined
Aug 29, 2017
Posts
191
OK so let me start off by saying this thing was a mess.

I got is pretty cheap and in non-working condition. It was covered with some kind of Grease, smoke or Tar. it also looks to have been spayed with some kind of bug killing substance, anyway it was full of presents(dead bugs) when i opened it and cleaned it out.

The System was playing Hucard's but the CD bios looked corrupted. I started to test and applied some pressure around the Cap's by the red and white connections on the left hand side of that. this made the Bios corruption clean up. then i tried loading a game and it loaded up with some pressure being applied( i think). So after this i decided to continue to clean up and recap the system in hopes this would solve the issue. well it did not. after recap the system stopped loading up games. but looked like it was trying. I then noticed the BA6290A chip was getting extremely Hot very quickly. maybe only after a few minutes of working. I know they normally get hot but this was way more than normal and the disks stoped spinning. So i tried Adjusting the pots Stupidly i tried all of them and forgot to mark the board(not sure why a Brain fart maybe). So i decided to give replacing the BA6290A with a good one from a CD rom rom drive i have. I also at this kind reflowed everything on the top and Bottom pf the PCB on the CD since of things. This made the disks start to spin again. but it was still not loading up any thing. so i tried adjusting the pots again and again. Using a few Guides posted on the net. To no success. At this point i noticed that the pot started to ware down and the readings started to fluctuate a lot. i tried matching it two a few configurations i found online but no luck. So i did the right thing and picked up another Duo. This one also had some issues and i managed to fix it. So now having a fully functioning one i decided to swap the lens and found that the lens was not working on the new working system. so i ordered a two new ones and also pot replacements 10k,20k and 500ohm. I also picked up an analog oscilloscope(100mhz) for a good deal(i needed one anyway) This brings us to present time. I have replaced the laser with a working one(tested on a working duo) I have replaced all the Pots and adjusted them Using the by ear and oscilloscope without any luck. Any tips or suggestions would be great. Check out my video below of the System running and how it looks on my oscilloscope and the current Pot settings. Also you can hear how it sound when trying to boot a disk.

Thanks again for any help you can provide.
 
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