Any Repair Logs or other info for Konami System GX?

[twistedsymphony]

I've got a bunch of Konami System GX boards and I have 2 faulty main boards.

Faulty PCB1: No video output; solid black screen.
This PCB was originally paired to Run and Gun 2 Sub-board which being a dual monitor game uses the SUB board for video output, leaving it with Run and Gun 2 it works perfectly and passes all tests. If I swap to a normal sub board (like say Salamander 2) which relies on the main PCB for video output I get the blank screen.

Faulty PCB2: No Audio output; dead silence.
I'm fairly certain the audio amp is working, if I crank up the audio in the test menu I get a nice amplifier buzz in the speakers... just no game audio. This PCB is a Daisu Kiss, though I don't think that matters. Again this one passes all tests. I haven't tried swapping out the SUB board on this yet, but either way I'd like to get both the main board and the sub-board working.

Anyone know of any System GX repair logs that might lend some insight or has anyone ever fixed any similar problems on these PCBs?

 

[rewrite]

No answers but I'm also interested as I'm sitting on a handful of non working motherboards.

 

[stj]

does it have an eeprom you can reset??

 

[twistedsymphony]

does it have an eeprom you can reset??

yes, and it makes no difference.

On all Konami GX games you need to hold test on boot to reset the EEPROM whenever you change ROMs boards, so that's something that has been done multiple times on both of my boards (and on rewrite's since we've both been buying these up and swapping around boards).

 

[caius]

As for the lack of audio I suspect the '056602' ceramic module, I attach a picture of it

I had a quick look at it, it's essentially a DAC plus a pre-amplifer section, it could be reproducible so I put it on my TO-DO list.

By the way, I recetly reproduced another Konami GX custom, the '056820', it's a sort of video amplifer but it provides also +5V to the VIDEO DAC, this is reason why it gets very hot (I guess dissipation is not enough)

 

[Astro X]

I also need one...........

 

[twistedsymphony]

As for the lack of audio I suspect the '056602' ceramic module, I attach a picture of it


I had a quick look at it, it's essentially a DAC plus a pre-amplifer section, it could be reproducible so I put it on my TO-DO list.


By the way, I recetly reproduced another Konami GX custom, the '056820', it's a sort of video amplifer but it provides also +5V to the VIDEO DAC, this is reason why it gets very hot (I guess dissipation is not enough)

Thanks for the analysis. Is there a good way to test/confirm if either of these modules is the culprit?