Thursday, 27 May 2021

Fender Passport Powered Mixer, Power Supply From Hell

Fender Passport PD-500
This 500W per channel portable Mixer/Amp is now back up and running.
After the service agents declared the equipment US (un-serviceable), I decided to give it a go, since I have the time and don't have to make a living fixing blown-up switch-mode power supplies. 
It's a tough one, for a technician. The failure is often very destructive which makes it hard, if not impossible to do a repair/reconstruct financially viable.
Exploded capacitor remnants

Incorrect value capacitors ill-fitted

Where the failure started, creating a domino effect of cascading failures

Circuit diagram indicating points of failure

The Fender Passport PD-500 in particular is a rather complex design. Repairs are usually done by board replacement, which is prohibitively expensive, which relegates too many PD-500's obsolete.
They can be fixed however.