Precision Power pc450 Fixable?

[Wigsplitter]

It looks like Q3, Q62, and R174 are all burned, If those three are replaced is it likely it will work? Or is there probably other issues? Where can I find these pieces. Thank for any help you may have. Q3 and Q62 both say SEC, 529 IRFZ44 on them.

[Perry Babin]

It's likely repairable, assuming that the transformer is not shorted.

You MUST replace all6 of the IRFZ44s. You can get them from Mouser or Digi-Key.

You also need to check the output transistors.

If you haven't done so, you need to read the basic amp repair page (link in sig line below).

[Wigsplitter]

Thank you for the info.

[Wigsplitter]

I replaced all 6 IRFz's and the 3 burned diodes on the lower side in the picture. The front channels work great but not getting and sound from the rears. Any suggestions?

[Perry Babin]

With speakers connected, did you try operating all pots and switches through their entire range to see if the amp ever produced audio?

[Wigsplitter]

Upon further testing the other channels do work when the xover freq. is turned all the way up. Its not as loud as the other channels but it does have sound.

[Perry Babin]

Gains?

-12db switch?

[Wigsplitter]

Yes I adjusted both gains, and turned -12 on and off. Now that I think about it, Im going to try a different set of RCAs.

[Wigsplitter]

After I said RCA's I realized this is not s left/right issue, but a front back so that cant be it.

Ok so I spent my lunch today really looking at it. So everything on the amp works, Its just that the front 2 channels are a lot quieter then the rears. You have to have the xover freq. turned all the way to the right to get sound out of the front channels. I would say they are 1/3 rd as loud as the rear two channels, and that is with the gain all the way up.

What most likely causes an issue like this?

[Perry Babin]

Do you read ~20 ohms of resistance between the input RCA shields of all 4 of the channels?

No RCAs connected.