Pc2150

[SS64]

Ok I have this amp I bought to repair. Had several burnt outputs, Bad hybrid board and blown supply. Right now I have the outputs and the drivers pulled. I replaced the blown hybrid board. And I have one z44 on each side of the supply for testing. I have +- 41.1 volts on the rails and my idle current is 1.112 amps. Here's the problem I'm having. The 6488's and the 6491's that supply the 15 volts run very hot almost instantly. It usually takes all of 30 seconds before they get hot enough to burn me. All four do this but the positive side get a little hotter quicker. So does anyone have any ideas? Where do I start?

[Perry Babin]

These are voltage regulators. They are constantly dissipating a few watts of power. They will run hot and may fail if not clamped down. If you clamp them to the sink, they will stay cool and you can continue troubleshooting.

[SS64]

Alright Thanks Perry. I talked to a old ppi tech and he couldn't even remember.... Figures....
Good to know I'm on the right track. The old tech also told me that ppi subbed the 35 and 36's on the outputs for some larger higher output parts. He couldn't remember the numbers. Would you happen to know what they are?

[Perry Babin]

They may have used any of the following but for an amp with low rail voltage, the TIP35C and TIP36C are probably the most rugged.

http://sigma.octopart.com/102148/dat...r-MJL21193.pdf

http://sigma.octopart.com/101286/dat...ba-2SC5200.pdf
http://sigma.octopart.com/101280/dat...ba-2SA1943.pdf

[SS64]

Thank you again Perry. Now All I have to do is order my z44's from mouser.