PCE Duo - some games work, others don't

[Xalusc]

Hello, everyone.
I have a PC Engine Duo which was fully recapped, and it's having some strange issues.
Some CD games work perfectly fine, music and all.
Others have some... issues.

Others simply don't boot at all.
I'm using pressed, high-quality replicas (think of PCE Works. Not from them per se, but you get the idea).

Here's a list of games I tested on it

Working 100%, no issues

• Gate of Thunder
• Dracula X
• R-Type CD

Working, but has issues

• Kaze Kiri - runs OK, but sound effects don't play for some reason

Not working

• Winds of Thunder - PCE stays on "loading..." screen for quite a long time, then goes back to "please insert disc" message
• Psychic Storm - tries to load, but then returns a "Load Error!" message
• Cotton - gets past loading screen, but then goes into a black screen and doesn't go past it

And yes, I've tested the working games immediately after getting these errors from non-working ones and they still played just fine.

Any ideas on what might be the issue here?

Thanks in advance

[majors]

Working, but has issues

• Kaze Kiri - runs OK, but sound effects don't play for some reason

There are smarter ppl around here but just from my exp, on your Gate of Thunder on the 1st stage when the enemy cruiser lowers and the wing hits the bottom and explodes, do you hear it? (sample pic) If not, this can be a sign of a bad ADPCM chip. Another test is running Buster Bros/Pomping World...if you do not hear any sound effects (red book audio will be fine), then you have ADPCM woes. I know you wrote "work perfectly fine, music and all" but it took me a hot second to figure out one of my Duo's was having odd sound issues.


Maybe some of the games need to access/load data to that audio section of your Duo. I assume chip games have no issues running (they do not use the extra audio capabilities of the Duo)

[Keith Courage]

Actual pressed discs? Not the light green or darker green/bluish CDR discs?

Kind of sounds like all of this could be caused by lens reading issues. This could be the lens getting weak, lens adjustments needing to be done on the board, or the DUO just not liking your discs altogether. I've worked on so many DUOs and 1 thing I have found that is a constant. No matter what lens adjustments are made or if the system has a new lens, many DUOs are just ultra picky about what kind of CDs they use. Some DUOs will only work with one type of CDR dye vs another. Meaning some require the light green dye and others the darker green/blue AZO dye.

Your DUO might just require a lens adjustment.

Also, you should try testing your discs with Turborip to make sure they don't have any errors. https://www.pcenginefans.com/forum/index.php?topic=1604.0

[Xalusc]

There are smarter ppl around here but just from my exp, on your Gate of Thunder on the 1st stage when the enemy cruiser lowers and the wing hits the bottom and explodes, do you hear it? (sample pic)

Yeah, I hear it!
Hey, I just realized something.
The AC Adapter I’m using outputs 0.5A whereas the original OEM adapter outputs 1A.
Do you think that might be the issue?

[Keith Courage]

Yes, that can be a big issue. A Duo should definitely have at least 1A(1000ma) from the power supply.

[Xalusc]

Okay, I'm gonna get a new power supply and try again. I'll come back with the results