be sure to check vias when recapping PCE/Turbo Duos...

[jd213]

Thanks to Luke at Console5, I was recently able to diagnose a via issue on a PCE Duo that had audio problems even after a recap and replacement of all the 4558 op-amps:
The console at first seemed to be in perfect working order after the recap, but then the CD audio got slowly quieter after about 20 minutes, then became almost totally mute (but still slightly audible with the volume turned all the way up).

I first thought it was maybe a capacitor problem or maybe the M51131L chip, as I've seen it mentioned as a possible cause, but I was able to use cold spray to pinpoint the issue to a couple vias in the audio section (one of which was connected to pin 8 of the M51131L, so the bad connection made it lose voltage at that pin which controls the volume).

Cleaned the vias, took a bit of solder mask off with a fiberglass pen, soldered in some thin resistor legs to make sure the vias make a solid connection, and the audio problems are gone (at least after a few hours of testing).

The old capacitors weren't very leaky when I replaced them, and the vias didn't appear in bad condition, so not sure if this was a corrosion issue or a poor manufacturing issue. Maybe a bit of both.

[PC Engine Fan X!]

Thanks to Luke at Console5, I was recently able to diagnose a via issue on a PCE Duo that had audio problems even after a recap and replacement of all the 4558 op-amps:
The console at first seemed to be in perfect working order after the recap, but then the CD audio got slowly quieter after about 20 minutes, then became almost totally mute (but still slightly audible with the volume turned all the way up).

I first thought it was maybe a capacitor problem or maybe the M51131L chip, as I've seen it mentioned as a possible cause, but I was able to use cold spray to pinpoint the issue to a couple vias in the audio section (one of which was connected to pin 8 of the M51131L, so the bad connection made it lose voltage at that pin which controls the volume).

Cleaned the vias, took a bit of solder mask off with a fiberglass pen, soldered in some thin resistor legs to make sure the vias make a solid connection, and the audio problems are gone (at least after a few hours of testing).

The old capacitors weren't very leaky when I replaced them, and the vias didn't appear in bad condition, so not sure if this was a corrosion issue or a poor manufacturing issue. Maybe a bit of both.

Would this apply to the NEC Super CD-Rom2 Interface Add-on as well?

A few years back, bought an RGB-modded Super CD-Rom2 Interface Add-on that was re-capped and internal gears that power up the CD-Rom drive were greased up -- it works flawlessly with PC Engine, Core Grafx II and SuperGrafx consoles. It's nice to have real PCE hardware on-hand (besides the usual reliance/fallback & ease-of-use with the Turbo Everdrive & Turbo Everdrive Pro + EDFX add-on to play all CD-Rom2, Super CD-Rom2 & Arcade CD-Rom2 titles nowadays).

It would seem like having a PC Engine Duo-RX and Turbo Duo consoles (or even the Super CD-Rom2 Interface add-on) aren't needed/unnecessary these days prior to the advent of the TED Pro release but they do have their quirks/charms and are aging gracefully like "fine wine as the years go on by" -- wouldn't have it any other way, console-wise, as they're regarded as a classic.

PC Engine Fan X! ^_~

[jd213]

I've never had a Super Rom2, but if it's already recapped and currently works then I wouldn't worry about it too much, maybe re-grease the rails and gears every 10 years or so.