Pioneer M22 will not power up

[tyrion]

My M22 will not power up. I worked fine earlier in the day yesterday. I shut it down for an hour and it would not power up again. I took off the bottom and the fuse seems to be intact. Did not see any issue with the power cord connection inside. Any suggestions on where to send for repair? Thanks.

[kevin gilmore]

no power on light?

There are 5 fuses inside. You will need an ohmmeter to actually check them.

 

[tyrion]

Thanks Kevin. Correct, no power on light. I need an ohmmeter and someone that knows how to use an ohmmeter. 

[kevin gilmore]

i have the schematics if you need them.  no power on light means that either of 2 of the 5 fuses have popped. If its the primary fuse, put in a new one. If its the secondary fuse, likely you have shorted output transistors. And getting parts for something that old in this covid economy is next to impossible. replacement semiconductors work but don't sound anything like the originals. And some oscillate etc...

Or just replace all 5 fuses and turn it on and see what happens. You might get lucky

But given its age...

input fuse is 3 amp

amplifier fuses, 2 each on each circuit board are 500ma

all are 3ag size

Edited November 7, 2021 by kevin gilmore

[tyrion]

Thanks again. I only see one fuse so I am guessing it would take some work to get to the others. Not sure why there is a strip of paper taped to the I side  

[kevin gilmore]

that is the input fuse and looks ok.

The other fuses are on the circuit boards the power light is hooked to the fuse on the right channel circuit board.

That piece of paper is protecting something from shorting out and definitely was not stock issue.

attached manual shows how to get the circuit board out. 2 screws and 11 connectors...

pioneer_m22.pdf

[tyrion]

All 5 fuses look good. 

[kevin gilmore]

bad power switch?

which would be an easy fix.

could also be a burned out light bulb and the amp actually works fine.

or no power to the amp.

voltmeter even super cheap piece of crap is very helpful.

Edited November 7, 2021 by kevin gilmore

[tyrion]

Amp doesn’t work. I have a voltmeter that needs batteries. Will be ordering some. I love the amp. I am told there is a guy that works on these so may end up sending it as my skills are very limited. 

[n_maher]

Before launching it somewhere definitely get some batteries for the volt/ohm meter and check the fuses the right way (not visual) as one or more of them could be shot and you just can't see it.  It'd also be good to check to make sure power is actually getting to the amp and then see if it's getting beyond the switch (like Kevin suggested) and then check a few other things.  Hard to imagine that it just went poof one day without any sign/smell/etc. 

[swt61]

If it's the same guy that used to refurbish them, he no longer does. He had a year long waiting list back when he did work on them. I bought my M22 because it was already refurbished by him.

[dsavitsk]

It looks like the earth wire is not connected to anything. Probably someone had a ground loop and disconnected it in an attempt to solve that.

There's a pretty extensive thread on these at SBAF.