Pioneer SX-980 - Diagnosis

[cecilk]

The replacements are a bit more robust and shed heat a lot better than the originals. If the originals are out, just replace them.

Ok - I replaced Q1-Q4 and D8-D9 last night - will also do Q5 and Q6 later today - perhaps will do D10-11 too.

Capacitors with a 105*C rating are a must here.

Yes - I got the Nichicon UPW caps as per the AK BOM for this unit.

Any resistors and diodes replaced should be lifted up about 1/4" away from the board.

Good tip - Thanks! I also have a few small heat sinks that I could attach to the existing heat sinks around Q1 and Q4 - May help disperse heat. I applied a thin layer of Thermalcote between Q1 / Q4 and the heat sinks so that should help too.

Will try to get this finished tonight and then will test voltages with DBT!

 

[cecilk]

Just finished replacing Q5 & Q6 and plugged in the unit to the DBT. Turned it on - fuses did not blow!

Tested voltages on the AWR-158 Power Supply board:
PIN SPEC MEASURED
Pin 16 +13v +12.55v
Pin 20 +33v +33.25v
Pin 22 +50v +50.1v
Pin 23 +23v +24.05v
Pin 25 -23v -23.8v
Pin 27 -50v -50.0v
Pin 28 -13v -13.13v

The unit came to life - I was able to tune in an AM station and an FM station and get sound through speaker. HOORAY!

Now - a few bulbs are out:
* Two of the three interior backlight bulbs
* FM bulb/LED
* STEREO bulb/LED
Anyone know a source for these?

Is it safe to use without the DBT now?

I'm going to Deoxit switches and pots and put it back together to do some more thorough testing of phono and aux inputs.

Are there any other recommended additional tests or checks I should do before that?

Thanks again, everyone!

 

[cecilk]

UPDATE: I just got done with a recap/rebuild and the SX-980 is now working beautifully! I love it!

This thing gets LOUD and sounds great!

Thank you to all who contribute to these forums! This site has been so invaluable - I just became a subscriber.

 

[zebulon1]

Very nice
A good job.

 

[cecilk]

Very nice
A good job.

Thanks!