SX-1010 Transformer Dead?

Dim bulb was not your problem.

Something was wonky with the wiring and is NOT present now.

I just did this, both the left and right amp boards would only go up to 1.750VDC between pins 10 & 13, the VR2 trimmers were fully clockwise. Afterwards reset the trimmers to fully CCW 0.0 OHMS... readings on pins 10 & 13 black dmm to ground are the original readings:

Right Amp

Pin 10 +0.350VDC
Pin 13 -0.360VDC

Left Amp

Pin 10 +0.370VDC
Pin 13 -0.360VDC
Click to expand...

These are GOOD readings. when actually having idle current you will find them at about +0.6v and -0.6v.
 
Quite frankly, since the outputs test good in the 6 way test, it is OK with me for you to try reinstalling the output transistors - AND WHILE DOING IT, ESTABLISHING a good connection to the heat sink (bare metal - like a screw thread etc - NOT paint ) with an ohmmeter and checking for shorts at each lead to the heat sink after every transistor is installed.
 
I have some news...came home from work, re-installed all the original transistors with new compound. Made sure there were no shorts, tested every terminal for shorts and continuity. Fired up on 100W DBT..lights, camera, action! The damn thing started up! Light bulb dimmed to nothing! No smoke, no sizzle, no bad smell, just the protection relay and the slight hum of a perfectly working transformer.
I'm gonna tickle the dragon's tail first, before full power.
 
Adjusted dc offset to 0.0VDC on both channels, then tickled the dragons tail, up to 50mv, back down to 0mv then up again on both channels. No problems so far, I think she's ready for a full blast of house power.
 
that's great news ..
i am still wondering what the fault was .. guess we can say the transformer is ok .
don't forget to put some new caps in next to the rectifier they cut down the switching noise of the diodes .
 
Thanks to Pete, Mark, and Zebulon for all the help with this, I really appreciate it!
 
Having the same problem with a 1010 here, found this thread and was very excited. I too thought my transformer was bad until I read more here and it dawned on me that I had not disconnected the amp supply on /both/ sides of the center tap. Did that and the dim bulb stayed dim and after I put the fuses back in I saw lights and heard relays. I continue reading to see what the solution here was and I get to the end of the thread and.... No diagnosis! Still, lots of great info and tips in this thread.
 
You must log in or register to reply here.

Similar threads

tsd71
Bad Luck lately another SX-1010 problem.
2
Replies
24
Views
2K
markthefixer
markthefixer
ILikePioneer
What a way to bring in the New Year. SX-1010 OUCH!
3 4 5
Replies
96
Views
5K
Grog
Grog
Bradbrews
Another SX-1010 this time a transformer
2 3
Replies
56
Views
2K
Bradbrews
Bradbrews
C
Pioneer SX-1010, 1050, 1250 efficiency
Replies
3
Views
984
markthefixer
markthefixer
HWKI
Pioneer SX-1010 diagnosis of FM muting
2
Replies
32
Views
3K
HWKI
HWKI
Back
Top Bottom