PCE CoreGraFX no sound problem

[jonasanu]

Hey

so finaly i found PCE CoreGraFX in decent shape for nice price, everything working good except sound.
Video is crisp and sharp from A/V output, but cant get a sound working, not a single blip:(

Please has anyone same experience? Its easy repair just by recap, or its a soundchip busted?
Thanx for any advises.

[tbone3969]

Caps.  It's always the caps dude.  Get them replaced and your all set.  I recommend Kieth Courage.  He does great work and his prices are very reasonable.

[jonasanu]

Have you tried tapping audio from the expansion port? This would let you rule out your a/v cable or the connector at least.

http://www.cgquarterly.com/2010/04/26/building-a-turbografx-16-pc-engine-composite-av-cable/

Will try that tonight. thanx for tip!

Caps.  It's always the caps dude.  Get them replaced and your all set.  I recommend Kieth Courage.  He does great work and his prices are very reasonable.

Isnt it strange its affect just a sound? Will replace them myself, im doin it all the time with my vintage synths

[Keith Courage]

I have never come across a regular white pc engine or core grafx that has needed new caps. If you try the expansion port and there is  no sound then the main hu6280 chip could be bad. Hopefully this is not the case.

Have you opened up the system yet? I worked on one once that had no sound. Turned out it was because the previous owner had soldered in some cable for an unfinished mod that shorted out all kinds of things. I removed his wiring and all was back to normal.

[jonasanu]

I have never come across a regular white pc engine or core grafx that has needed new caps. If you try the expansion port and there is  no sound then the main hu6280 chip could be bad. Hopefully this is not the case.

Have you opened up the system yet? I worked on one once that had no sound. Turned out it was because the previous owner had soldered in some cable for an unfinished mod that shorted out all kinds of things. I removed his wiring and all was back to normal.

Yeah i though it was DUO problem not regular PCE.
Iv tried expansion port, but no luck:(.
Opened case, its looks like new inside, no busted mods seen.
Hope its not a main chip (

[Keith Courage]

Pin 17 and 18 on the hu6280 are the audio pins. Try checking those to see if there is sound. https://www.google.com/search?q=hu6280&client=ms-android-americamovil-us&prmd=mvin&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiB3MOR_u3OAhUM5SYKHRc6DI8Q_AUICSgD&biw=360&bih=559#imgrc=h8a18aZoOsivlM%3A

don't forget hook up a ground like a regular rca cable when testing these pins. Some people accidentally forget that. any grounding point should do.

[jonasanu]

Pin 17 and 18 on the hu6280 are the audio pins. Try checking those to see if there is sound. https://www.google.com/search?q=hu6280&client=ms-android-americamovil-us&prmd=mvin&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiB3MOR_u3OAhUM5SYKHRc6DI8Q_AUICSgD&biw=360&bih=559#imgrc=h8a18aZoOsivlM%3A

don't forget hook up a ground like a regular rca cable when testing these pins. Some people accidentally forget that. any grounding point should do.

Thanx a lot for tips, youre ace!

[jonasanu]

Pin 17 and 18 on the hu6280 are the audio pins. Try checking those to see if there is sound. https://www.google.com/search?q=hu6280&client=ms-android-americamovil-us&prmd=mvin&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiB3MOR_u3OAhUM5SYKHRc6DI8Q_AUICSgD&biw=360&bih=559#imgrc=h8a18aZoOsivlM%3A

don't forget hook up a ground like a regular rca cable when testing these pins. Some people accidentally forget that. any grounding point should do.

So i try pins on expansion bay again, and it seems there is some sound, but very very quiet i have to crank Tv all the way up to just hear a bit.

[Keith Courage]

That is weird. I wonder if the op amp went bad. I guess bad caps shouldn't be ruled out but it would be really odd if any were bad. Did you try to get audio straight from the hu6280 chip yet?

[jonasanu]

That is weird. I wonder if the op amp went bad. I guess bad caps shouldn't be ruled out but it would be really odd if any were bad. Did you try to get audio straight from the hu6280 chip yet?

So finally i found out its a bad connection i power connector i have to viggle it to hear a sound, strange.
Thanx everyone for help

[Keith Courage]

You mean your AV cable? Could be that your Din socket for the cable is bad but then again it be the cable itself as well. Both are known to happen.

[jonasanu]

You mean your AV cable? Could be that your Din socket for the cable is bad but then again it be the cable itself as well. Both are known to happen.

No its a power supply socket.

[Nazi NecroPhile]

So insufficient power getting to the system?  Weird.

[Vimtoman]

Is it audio or just noise when you wiggle the power connection?

If its noise then it shows the audio amp is working and the connection to it is the problemo.

[jonasanu]

Well it seems rather more complicated.
I solder out original power plug and replace it for a new one.
Its bit better, will power up, sounds and picture works good, but after minutes or so, picture fade to darker tones and than system shut off completely. Also if i shake a PCE bit, will shut down too.
Weird...any suggestions?
What i should check? Its seems something wrong with power section.

[ClodBusted]

Sounds like some cold solder joints or fractures in the PCB if you'd ask me for a rather uneducated guess.

[jonasanu]

Saga continues. I desolder and exchange for new ones power+AV sockets, its helps, but still shuts down randomly after few minutes, if i wiggle ribbon cable from card to motherboard, sometimes its works again for a bit.
Could be a bad ribbon cable? Seems like pain in the arse to desolder this sucker out

[MNKyDeth]

The ribbon cable is not fun, but if opening and closing the system a few times it is easy to break the wires off without knowing it.

I have cut the cable down before and made it slightly shorter or as I think a few people here they use old ide style cables to replace it.

[jonasanu]

I dont know whats goin on.
I replace AV cable,AV DIN connector and power supply connector also fuse, but still have a problem with sound and video.
Also Street fighter card starts to glitch, see this video ! What is goin on?!

[Keith Courage]

That video looks like bad video ram. Especially if Street fighter 2 is used since it is a 20meg game.

[jonasanu]

That video looks like bad video ram. Especially if Street fighter 2 is used since it is a 20meg game.

Its there a possible remedy, or i have to find another pcengine?

[jonasanu]

Strange thing is, its works before.

[Keith Courage]

if it worked before then there's a good chance that there's some broken Connections in the ribbon cable for the hu card connector.