New Colecovision, new sound problems

[TheSolderMonger]

Earlier on I damaged a colecovision with a green screen issue, this time I have another system with sound issues, and adjusting the RF pots while DK was playing showed no results. The sound issues consist of beeps during the start of donkey kong and no other sounds, this problem persists on the boot screen and on other games as well. However, I noticed that if I were to short pins 6 and 7 on the SN76489 sound chip, the sound comes back! Though there is some interference with the graphics, the sound comes back on with a bit of static and removing the short causes the graphics to clear up, but sound is lost as a result. Could a solder reflow on pin 7 of the chip or a check for a fault solve the sound problem?

[Taijigamer]

Use sheet 6 of the Colecovision service manual to help troubleshoot the issue. http://www.colecovisionzone.com/photos/coleco/colecovision%20tech4.pdf. Check 5V on pin 16. Check that pin 5 & 6 go low when playing game. Check pin 14 for clk signal.

 

It may be a bad sound chip. This thread details a similar issue. http://atariage.com/forums/topic/214438-colecovision-no-sound-problem-help/

[TheSolderMonger]

Use sheet 6 of the Colecovision service manual to help troubleshoot the issue. http://www.colecovisionzone.com/photos/coleco/colecovision%20tech4.pdf. Check 5V on pin 16. Check that pin 5 & 6 go low when playing game. Check pin 14 for clk signal.

 

It may be a bad sound chip. This thread details a similar issue. http://atariage.com/forums/topic/214438-colecovision-no-sound-problem-help/

 

Using my dead CV, I used a heatgun instead of a solder iron to remove the chip and piggyback, and sound came back! So I swapped the chip and now sound works properly. Now I have a fully working CV and a parts donor.

 

Thanks for the help!

[Taijigamer]

You're welcome =) Glad u got it sorted.