Hi Everybody,
I'm having a bit of an issue here with the PC Engine Duo listed as no power off eBay last week. When I got it, it was mostly recapped by the previous owner (Horrible job).
Before turning it on, I opened it up and checked for any Vcc and GND shorts, but it was fine.
Grab my only PC engine HuCard (Street Fighter II), slided it in, turned it on and behold white screen. Turned it on and off a few times and I'm also getting purple and yellow colored screens along with multi-colored screen that moves (I hooked up the duo to my capture card). So I thought let me check the CD portion. Took out the hucard, turned it on. Same thing, white screen
.
Since the caps were no name or an unknown brand, I swapped them out with a Console5 SMD cap kit and still same thing.
I also tried out other things, but still nothing (Not in order).
Reflowed 6260
Replaced 6270
Replaced 6280
Replaced Video Ram
Replaced Work Ram
Checked HuCard connector for shorts
Replaced logic IC's except IC517 (2 were running very hot - almost enough to burn your finger but replaced all except IC517).
Spent about 3 days straight working on it and for the life of me can't figure this one out
. Anybody have any ideas?. Any help is greatly appreciated.
*Edit* Checked all traces of 6270 using the netlist and had 2 bad traces, but symptom's are still there:
http://gamesx.com/wiki/doku.php?id=hu6270_netlist*Edit2* Checked all traces of 6260 using the netlist and had 1 bad trace, but symptom's are still there:
http://gamesx.com/wiki/doku.php?id=hu6260_netlist*Edit3* Checked all traces of 6280 using the netlist and had 2 bad traces, but symptom's are still there:
http://gamesx.com/wiki/doku.php?id=hu6280_netlist .
*Edit4* I whipped out the oscilloscope and found that the 6260 is only getting 60hz? (Sounds like it's for NTSC video, but Netlist homepage shows it should be getting 21mhz?. The 6280 is getting 21mhz though).