How do I fix an output transistor amp that blew?

Answer by  aairon (10)

Identify the output devices (NPN and PNP) De-solder them and look up replacements, Purchase matched pairs only. Clean the heatsink and apply heatsink compound and mount the transistors with the hardware, making sure to install the insulators. Re-solder the transistors, Check for solder bridges. If all is OK reapply power.

Answer by  dvdpro (96)

Determine what failed within the amp first. If you're able to determine that, determine why it failed. If you're unable to answer both of those questions, fixing it will only serve to allow for it to blow again. Best thing to do first is open it up and look for visible signs of failure.

Answer by  pharkus (22)

First establish which transistor is blown (with power off, check for continuity collector to emitter. "Blown" transistors are usually shorted both directions). Unscrew and desolder. Coat back of new transistor with thermal compound, solder in, screw down. It's usually a good idea replace transistors in pairs, even if the matching one isn't blown.

Answer by  Jalaine11 (2043)

The first thing you might check is to see if the fuse blew in your amp. Once you locate the fuse, try replacing them with a new one to see if that fixes the problem. If not your power supply could be the problem. It might be best to take you amp to a professional.

Answer by  Rano (84)

Locate output transistors. They are the largest transistor mounted on heath sink. Note down their type and purchase new. Use solder iron with pump to unsolder leads. Carefully unscrew transistor casings, preserve case to heatsink heath insulator and replace with new transistors. Take care of the heath sink insulators. Then solder new transistor leads.

Answer by  Travis404607 (3916)

If the output transistor amp blew, it likely had a surge of power to the core and ruined it. The entire thing needs to be replaced and reinstalled where the old one was.