driver testing [resolved]

[joralieu]

Driver testing I have 513 on 1A and 152 on OA also the LEDs on the B side are both out. It's the same for the A and D socket. Where do I look first.

 

[Paul Birkeland]

I would post some photos of your build so far.  The 152V at OA could be related to the zener diode installation on the 5 lug terminal strips behind the 9 pin sockets, but I would bet on a missing jumper or a jumper going somewhere it shouldn't be on the PC board itself.

 

[joralieu]

Here are some photos

 

[Paul Birkeland]

It would likely be best to remove one of the boards, flip it over, and show a picture of the bottom as well.

 

[joralieu]

Another thought, I had my LM431A's in backwards. I desolderd them and turned them. Could that be the problem?

 

[joralieu]

Also had the JC29  backwards, had desolder and resolder them. Wonder if I may have damaged something in the process

 

[Paul Birkeland]

Did you swap the PN2907 with the 431, or did you install them all backwards?  If you put them in backwards and powered up the amp, then you will need to replace all of those parts.

 

[joralieu]

They were all in the right place but I had the flat sides facing the wrong way. I corrected that before It was powered up.

 

[Paul Birkeland]

What are you Kreg voltages? 

Even if not powered up, reworking these boards can be tough.  Still, you have the exact same problem on both boards, so the same error is likely present on both sides.

 

[joralieu]

Socket A        Socket D

Kreg A 4.1.    Kreg A .06
Kreg B 1.8.      Kreg B 1.8

 

[Paul Birkeland]

Both B side Kreg voltage indicate saturation, which would make me very, very interested in seeing the bottom of each C4S PC board.  I would wonder if there are solder bridges present between pins on some of the transistors that got swapped around.

 

[joralieu]

Here is the bottom side.

 

[Paul Birkeland]

Could you double check that you have the 2.49K and 249K resistors in the correct places.

 

[joralieu]

That's It, those are in the wrong places. Would powering that way damage anything?

 

[Paul Birkeland]

It's quite possible that the 431 regulators may need to be replaced on that side of the board, but you can power it up and see.

 

[joralieu]

Ok I have the resistors in the right spots now here is what I got.
A socket.            D socket
1a 519                1a 519
Oa 298.                Oa 349
All the led's light up

 

[Paul Birkeland]

OK, well the side with 298V is likely working properly.  What are the Kreg voltages on the side with 349V at OA?  Does the 5670 glow on that side of the amp?

 

[joralieu]

The 5670 on that side lights up Kreg A 3.75V Kreg B is 15V

 

[joralieu]

Any further advice?

 

[Paul Birkeland]

You had said before that both sides light up...

On the side with the OA at 349V, can you report both Kreg voltages on that side?