Q&A Thread

[hairy otter]

I spend some time tying to follow the tracks that are grounded, but its hard because if I try to beep where the track reapears, I often find an other ground. While tracking my eye caught one chip with 2 burned pins, its a smd with allot op pins, it says nec D65024GF035, and I cant find any info about it. One burned pin goes to +5v and the other GND. On to of the chip is a small bump so I think there's some internal damage.
This means the end for my repair attempt.

[channelmaniac]

Yup. Sounds like the chip is toast.

Can you post a close-up picture of the chip?

[hairy otter]

Here's the picture you asked for:


The bump I first noticed is below the "P" of JAPAN, now I also see a large crack between the two burned pins.

In full: Link   http://farm4.staticflickr.com/3790/11822836523_765190589d_o.jpg

BTW thanks for your support, 

[channelmaniac]

Yeah, that one is toast for sure. I see 2 cracks in the top of it too.

I did some digging and all I see are Chinese suppliers but no data on the chip.

[danzig8155]

Hello Channelmaniac. Long time listener, first time caller here.

I had a Street Fighter 2 Hyper Fighting board that I sold to a gentleman on another forum. When I tested the board in my test cabinet before posting it for sale, I was sure the sound worked. The gentleman, being an avid SF fan, says that not all the sounds work properly. Here is his quote:

"Only part of the music and sound effects are coming through while other parts do not, even when volume is turned up and down both on the pcb and on the cab. Sort of like an orchestra is playing with half the instruments missing."

I'm wandering if this is a few bad roms or, from what I've read on a few of your fixes, the Z80? I've never come across a board that had some audio not working. Any help would be appreciated. Thanks.

[channelmaniac]

Shouldn't be the Z80. If that were out you'd have no sound at all.

Look for gouged traces on the bottom of the A board and the top of the B board around the 3 ROMs for sound. 1 of them is the Sound Program ROM and 2 are for sound effects that play via the OKI sound chips.

Try to determine if the music is playing and the sound effects are missing. if so, check those 2 effects ROMs to see if they are bad.

Next on the list of possibilities would be incorrect sound program ROM or sound effects ROMs. So many of these boards and ROMs get swapped around by people that it's possible that they are mismatched sets.

If they check OK in an EPROM programmer and the traces are good then I'd recap the sound section on the A board. Those caps rarely ever go bad so I'd check the other items first.