Powerbass ASA1500.1D driver board burning resistor

[Perry Babin]

There shouldn't be any current through R193. Are you sure that Q113 is OK?

What's the DC voltage across R177?

 

[neonarossa]

Q113 = kta1275 is good. . .7v across r177. Q120,121 was measuring short. I cut the collector leg of each and it is in the board.
This is where the board is now.
Q113 was 2sb631k. Now"kta1275
Q112 was 2sd600k. Now"ktc3228
Q110,111 was 2n5551. Now 2n5551 again
Q116,117,118,119 was 2n5401. Now"ksp92
Q114= ksp92
All drivers and opamp are still good..

 

[neonarossa]

Everything on this schematic except q113. Mpsa92 (e.b.c) and q110,111 2n5551 (ebc) does not match board layout.

 

[Perry Babin]

Do you mean that the circuit paths are not correct?

Just looking at the connections, the pin configuration of the transistors and the polarity (not concerned with the exact part number) is the board you have completely different?

 

[neonarossa]

Im sorry. I wrote it wrong. Every trace and polarity match >except< q113 & q110,11. The (e.b.c.) pin configuration "dont match".. whenever i try to use them(even though they were installed) it burns as it did before any parts were replaced.. Im at a loss??

 

[neonarossa]

Q110,111 are the issue. If it is installed as ktc1027(e.c.b.) R171 will burn. Installed as 2n5551(e.b.c.) R193 will burn..

 

[Perry Babin]

The parts in the photos were OEM parts. Install them as shown in the photos and we'll troubleshoot.

 

[neonarossa]

Ok. I will finish swapping them..