peavey

[fellowesman]

need help with peavey pv8.5
there is a part on the driver board that blowen need help
fixing

[Leolabs]

First,check for shorted transistor(esp output stage).

[fellowesman]

is that on the driver board or output board?
thanks

[Netlist]

Fellowesman,
I'm afraid you have to provide more info.
Do you have the schematic? Are you familiar with tackling that kind of amps? What happened and what did you already attempt?

/Hugo

[fellowesman]

netlist
this is the lowdown
we were playing and the 8.5 smoked
now for whats blown is the mps-6533/34 transistior is completely gone
and mje-15031 driver transistior looks to have a hole in it
other than just replace the part that gone what else should be checked? i do have use of a dvm. is there a way to check the driver tran on the board
thanks

[Netlist]

Fellowesman,
this is not just random component failure but a rather major problem.
You will have to take out all output transistors and drivers and it will be best to replace them all if you want a good repair. Every diode and resistor will need to be checked in the output stage. Again, if you are not familiar with this kind of amps, I strongly suggest to take it to a good service point.

/Hugo

[fellowesman]

netlist
as you seen in earler post was just sent home after haveing a heart
attack. have plenty of time on my hands and very little money.
i did check with a repair shop near here and was told "just return it to
peavey" they would not even look at it. i have found that very few
places will fix i mean repair anything (replace componets) they just
want to replace the whole board!

i have the part lay out and the schematcs for this amp and the use of
a dvm. i should replace parts 200 204 and 100 104 along with parts
202 203 and 102 103
thanks

[Netlist]

Yes, all TO3 transistors should be replaced. Check and replace the diodes especially those build into the heatsinks.

Take care of that heart.

/Hugo

[fellowesman]

are they to3??
mine shows them to be to-220 and to-92
or am i wrong?
also what other things need to be checked?
what would make that part fail?

thanks ron

[Netlist]

Of course you are correct. We are talking driver board. I had the output board in mind. My schematic is so bad I can hardly read the part numbers.
So, check all you can, the visually damaged parts are definitely to be replaced, take out every transistor that measures slightly suspicious on that board and measure it out of circuit. Same with the diodes.
As for the output board, failure of the driver board could have damaged one or more outputs. Take your time and check them as well.
I hate to ask but do you know how to measure a semiconductor?
I'll gladly explain if not.

/Hugo