ppi pc450 problems

[jordan_ciaramit]

the pc450 comes on fine but has very low output. power suply and outputs tested out ok. no signs of blown traces anywhere. but i did find a small transistor(to-92) with a crack on the input side of the the amp.the problem is i can't identify the part number to replace it. it is shown like this:
J
1 0 8
P806CI

there is also one beside it listed the same but p818ey.

the location numbers are. Q1 and Q2.
if someone could help identify these part numbers i would appreciate it.

 

[shallowfu]

Can you put a picture up?

 

[1moreamp]

The J108 is a mute fet, and cracked is not good. It might explain the low volume issue, but theres probably more wrong.
Post a pic or two.
TO-3 might be able to help you sort a PPI issue. He knows them best.

hope this helps

 

[Perry Babin]

J108 is the part number for both pieces. The Pxxx number is a production/date code.

On some of their amps, there were two of these working in a quasi-parallel configuration for muting. If one received a signal that could cause it to crack, the other one is likely damaged. If they are indeed the muting transistors, you can pull them and the amplifier should produce audio (assuming that there are no other problems).

Be aware that removal of the transistors may allow a significant turn-on transient (pop) to pass to the output. If a low power speaker is connected, it may be damaged.

 

[jordan_ciaramit]

oddly enough a customer brought in the same exact amp to be repaired. it has a blown power supply. since my own personal pc450 was still on the bench i removed the 2 transistors from the customers amp and placed them in mine and it works perfect. so that was my problem. now to the customers amp. thanks for the help with the part number i can now purchase more.