Sound Skulptor forums

Build help and troubleshooting => CP554 Diode bridge compressor => Topic started by: norwood on January 17, 2024, 10:11:06 PM

Title: R32 burning
Post by: norwood on January 17, 2024, 10:11:06 PM

Within 10 to 15 seconds of powering up R32 begins smoking and burning. 

When powered up in small windows, I can meter V- to 0V as the correct -16V BUT V+ to 0V as basically nothing. 

I checked components, their orientation and re-flowed all solder joints but the same issue persists. 

I’m assuming I have a short between V0 and V+ or failed component somewhere?
Any advice on how to troubleshoot this board?

Title: Re: R32 burning
Post by: JPK on January 18, 2024, 11:23:10 AM

Is the V+ restored when the output transformer iss unplugged?
If true, check the output transformer connector: look for a short circuit between 2 adjacent wires.
If not true look for:

• Bad solder joint (reflow suspicious joints),
• Reversed components (electrolytics, diodes, transistors, IC's),
• Flipped transistors,
• Trim all the component leads and test pins as short as possible. Nothing must touch the chassis plate.