Roadshow: No sound at all

[63wizz]

I got a project Roadshow, and as with all my projects i like to get them running properly, before i strip them down, so i know if it don't work when finished Ive stuffed something up.
Any way the WPC DCS A-16917 sound board has no sound at all. the ROMS are fine because i put them in another board out of my Flintstones and put in the Roadshow and the sound works fine.
Clays pin repair doesn't have very much info on these boards because they are very reliable according to him. Ive ordered new amplifier (TDA2030A and TL084) parts from GPE they haven't arrived yet, and i hope that these will fix the problem.
If anyone is familiar with these boards and can help i would very much appreciate it.

Ian

[beaky]

test the whole board in another pin & see if it works.
also check that the ribbon cable to the sound board is fitted correctly.

[63wizz]

I put the sound board out of my Flintstones in to Roadshow (changed Roms) used the cables that were in the Roadshow and it worked perfectly.
Didn't try the other way because i have the DMD display out of Flintstones in the Roadshow while i wait for a new display.

Ian

[63wizz]

test the whole board in another pin & see if it works.
also check that the ribbon cable to the sound board is fitted correctly.

I put the Flintstones Roms in the none working board and installed in the Flintstones machine, NO sounds at all not even the loud bong.

Ian

[johnwartjr]

I would start by checking fuses and making sure the 4 big diodes are good. If the board can't get power, it won't work.

Does it display any errors? like interface errors? or no? Does the pin boot slowly, or normal speed?

[63wizz]

comes up with sound board interface error, but the Roms work fine in the other board, fuses are ok, checked the big diodes they are ok.

Ian

[63wizz]

well i got the new Amps and installed them and i still have nothing, no sound at all, not sure what to do next.
any one have any ideas what to look for.

ian

[bigdaddy]

I've had issues before where the bus driver chips for the interface go bad - can't remember the chip ID, but it will either load down the bus and the CPU won't boot with the interface in the board, or you get something like the symptoms you describe. You will need the circuit schematics and you can try from there. Hope this helps

[63wizz]

I have the schematics and im going through the board as there have been a couple of chips replaced previously.
dont know if the sockets have been put in properly, maybe a broken trace.

Ian

[robm]

Sounds like you and I have the same problem. Mine in a tz. I've replaced all the amps, the RAM and made sure the roms work and confirmed this board does not work in another machine.

I've made some observations with the logic probe. Pin 1 of u2 on a working board shows no signal, whereas on the dead board it shows low.  Also the all signals on a working RAM (u9 I think) are way different to the dead one even after putting new RAM in. I assume any 6264 RAM will work?

I've also reseated, swapped ribbon cables to make sure they are not the problem.

[63wizz]

I dont think your sound board is the DCS type, which has some different components on it.

i have read on RGP someone changing U32 so i have ordered a chip for U32 and will see what happens.

It has really got me stumped, and it doesnt seem like anyone knows much about the DCS sound board.

Ian

[63wizz]

Spent all day on this board, i have changed just about every socket and chip on the board and still nothing.

Ian

[dj10555]

Have you checked that the board has +5 & -5V volts from the two regulators. Also check the clock is working on pins 41 ,42 of the DSP. I have heard the 68 pin DSP chip on the DCS can fail.

[63wizz]

thanks will have a look at the DSP clock.

Ian



EDIT: Re checked + -5v, ok.
Checked pin 41 2.9v and pin 42 1.59v

[63wizz]

After many hours going over this board with the DMM checking continuity, i have finally found the problem, as i originally thought, it was a broken trace where the previous repairer had changed a chip and put in a socket.
There were 4 re socketed chips all up.

I went through the schematics with both sound boards, and compared the findings with the working board.

Hooray  i have repaired the trace and the board works 100% 

thanks too those who offered help with this problem

Ian