Pioneer PRS-D5000SPL

[Perry Babin]

If the 7570 IC is heating up without producing any drive signals to the output transistors (I'm assuming that the output transistors are in the circuit), I'd suspect that it's defective but I can't recommend that you replace it because I have no direct experience with an amp with these exact symptoms.

If you don't have the service manual, email me for it.
babin_perry@yahoo.com

You need to check the various voltages feeding the IC to confirm that none have greater voltage than they should.

 

[rrae]

Before even trying to replace 7570, i saw that i had ordered irf640 and soldered in. The originals was irf640N version. I know that RF can be tricky with N and non N versions.
Could this be a problem? But there wasnt any square wave on the outputs.

 

[Perry Babin]

I don't think the output transistors (assuming that they're not defective) can cause the IC to heat up if there is no drive signal from the IC.

 

[rrae]

Before replacing, i checked voltages again- i somehow got blown -20v regulation, Q703 and D715 are sorted. The diode (RD22EB2) substitute can be used 20V zener? And any thought on what to use in Q703, its 2SA2005.

 

[Perry Babin]

20v may be OK for testing. The transistor isn't critical.