switching power supply.. can't get -24v?

[AudioSan]

R5 is correct? 4.75Kohm. and not 47.5kohm.

 

[BScorner]

desolder R10 and R12 and pull them out

check again voltages at R7 and R8 , write them here

ground both inputs while doing testing like these

Across them?

R7 - .04
R8 - 8.43

 

[BScorner]

R5 is correct? 4.75Kohm. and not 47.5kohm.

Yes.

 

[6L6]

Please, before you do anything else, post some detailed, well-lit photos of your connections.

 

[AudioSan]

Across them?

R7 - .04
R8 - 8.43

try to desolder R9 and 11 and check R7 and R8.
i think Q7 is your problem.

 

[BScorner]

when i measure from chassis ground to source of Q4 and Q5 I get 2 ohms is this normal?

I get 1.5 ohm from chassis ground to Drain of Q8 & Q7.

All other pins appear open to ground.

 

[AudioSan]

that seems normal.

 

[AudioSan]

when i measure from chassis ground to source of Q4 and Q5 I get 2 ohms is this normal?

I get 1.5 ohm from chassis ground to Drain of Q8 & Q7.

All other pins appear open to ground.

you ment Q5 and 6?

 

[6L6]

PLEASE PLEASE PLEASE post some photos. Occam's Razor says (and you hint) that you probably have something mis-connected.

 

[BScorner]

pictures

pictures

pictures

 

[BScorner]

you ment Q5 and 6?

yes sorry, the mosfets

 

[AudioSan]

aiai. pluss from PSU1 to pluss in on the amp. minus out from PSU2 to minus in on the amp. and a link between minus on PSU1 to pluss on PSU2, and to ground on amp.

 

[6L6]

Ok, those look decent, but we need to be able to read the printing on the board.

Where is the output?

Do you have a link to the PCB anywhere?

 

[BScorner]

Ok, those look decent, but we need to be able to read the printing on the board.

Where is the output?

Do you have a link to the PCB anywhere?

Mosfet SE class A JFET input power amp stereo huge PCB! | eBay

 

[AudioSan]

Ok, those look decent, but we need to be able to read the printing on the board.

Where is the output?

Do you have a link to the PCB anywhere?

no it do not look okei.

 

[AudioSan]

you have only +24V.

 

[BScorner]

you have only +24V.

when i measure from chassis ground to +24 -24 points on pcb I get both.

 

[AudioSan]

connect pluss from left PSU to plus in on amp. minus from left PSU and plus from right PSU together and to amp ground. minus from right PSU to minus in on the amp.

 

[AudioSan]

in this case you have. you will see 48V over pluss to minus. but +24V from ground to minus. and not -24V🙂

 

[BScorner]

connect pluss from left PSU to plus in on amp. minus from left PSU and plus from right PSU together and to amp ground. minus from right PSU to minus in on the amp.

Yes i did this.. it is strange because both boards do the same thing?