pictures of my soundstream amp

[bluiezaccord]

Recap, the amp works but does not shut off when the key is out. It also makes a weird high pitch noise coming from inside the amp. I checked the ground, remote, all the wires. When I took out the RCA wire from the amp, it finally shuts off. This started happening ever since I had the subwoofers wired down to 0.5 ohm. I accidentally wired them wrong. I wanted it 2 ohm. So i took out the amp and opened it. Here is how it looks.. somebody please help me. Thank you.


When I opened it, I only saw the one of the transistor was burnt, and another one had one of the three leg broken....
And when I flipped it around... it looked horrible..

[Perry Babin]

One FET has obviously failed. It's likely that all of the others in that supply (the amp has 2 power supplies -- 8 FETs/supply) have failed also. Measure the resistance from leg 1 to the other two legs of the individual FETs in the supply. If any read near 0 ohms, they (or some in parallel) are defective.

Generally, when the power supply fails, it's because the output transistors (on the other side of the amp) have failed. Check them before powering the amp up again.

You need to clamp the transistors to the sink before powering it up again.

Which transistor had a broken leg?

What looked 'horrible'?

[bluiezaccord]

the back part where they have solder looks melted and has burned color

[jol50]

The large solders on the back may look that way because they have flux on them. Often they add solder to the large joints by hand or something, you can see they were done not like the rest of the board. Make sure they did not contact the case of the amp. They need a gob of solder on them to hold the heavy component without breaking. I'd say remove all parallel transistors and replace, check or replace resistors for them and it might be fine after some testing. Post a close-up photo of the large solders on the back of the board if you can, hard to see in that photo.

[bluiezaccord]

I Tried to add more solder to them. I checked and they have these black square stubs so that it would not touch the case of the amp. I was wondering if I can use transistors or resistors from my other amps that I am not using. If so, how would I know which one to use? Thanks for all the help guys. I really appreciate it.

[Perry Babin]

In addition to want jol50 suggested (replace all power supply FETs as well as all audio FETs), check the solder connections on the driver board. Q124 and Q125 overheat. If the solder connections are like the ones in the links below (rough/cracked), you need to replace both Q124 and Q125. Both are MPSA42s.

http://bcae1.com/temp/ttplanetaudiobadsolder01.jpg

http://bcae1.com/temp/ttplanetaudiobadsolder02.jpg

Do not use parts out of other amps.

[bluiezaccord]

Hey Perry,
Do you mean Q134 and Q135? If I replace those do you think that will solve my problem?

[Perry Babin]

No. These are on the vertical driver board near the fan.

[bluiezaccord]

Ok Perry. I will look at it rightnow

[bluiezaccord]

Here are some pictures. They didnt look bad at all.
The audio fet and supply fets are the transitors on both outer sides of the amp? Also, how did you know Q124 and Q125 was on that board? thats awesome