Duo-RX CD Games Work, Hucards Don’t

[Duxcub]

I mod and repair lots of Duo consoles, but I've never run into this. The CD part functions perfectly - SuperCD games play fine with no skipping or any graphical problems. The games actually run, I can control the character on screen and such. But no Hucard games will run, it's just a yellow screen. The slot is very well cleaned at this point, and the Hucards I'm testing with work on other systems.

I've tested continuity between the slot and huc6280, huc6270, and several chips on the bottom of the board (IC518,517,520,516, AND IC906). Based on simply visually following the traces, continuity seems good.

Is there a ram or other chip that is only used on the Hucard side that may have failed? It seems totally bizarre that the game part of the CD actually is playable if there's something wrong with a main chip.

Thanks everyone

[SignOfZeta]

You didn't mention the history of the system. I'm assuming some 'tard fucked up modding it at some point? It's exceptionally odd for a Duo to have its HuCARD side die without some help.

Btw, I would go beyond visually checking continuity at this point. If it's untouched then yeah, it's probably fine, but if you are rescuing this thing from a Doujindance situation then you need to get the meter out.

[Keith Courage]

this is a weird issue to have. The only time I've had a problem with the card games not working and the CD drive still working fine, it's either been caused by a problem with the card slot itself or traces on the motherboard.

[Duxcub]

Thanks for the replies so far.

I did test with a multimeter, but maybe i missed something. Lots of traces between the slot and multiple chips. I'll go over it again.

I just wanted to make sure i'm not missing something obvious that only the hucard side uses.

[SignOfZeta]

Aside from the slot I don't know if there is anything that is ONLY used by the HuCARD side. Some semiconductors of course but chips? Maybe someone knows %100 on that.

Now check for power, ground, and shorts, I guess. Good luck!

Oh, hey, dumb question, these are Japanese HuCARDs, right?