T2500-1bdcp no output.

[punch45x2]

Pin 2 of u2000 and u2002 after 10 seconds

 

[punch45x2]

Pin4 of u2000 and u2002

 

[punch45x2]

Pin 5 of u2000 and u2002

 

[punch45x2]

Pin7 of u2000 and u2002

 

[punch45x2]

The longer I leave the amp off the longer the drive stays stable as well as the current

 

[Perry Babin]

Is this with the rectifier center legs out of the circuit?

 

[punch45x2]

No I thought that was for checking output. This is with c118 jumped

 

[Perry Babin]

With the capacitor jumped, I wouldn't expect to see any output from the ICs.

With the rectifiers out of the circuit, the attached is what I'd expect to see on pin 2. You might need to close the local feedback on the driver board to get this.

 

[punch45x2]

I was doing what was asked in post 19. I will remove rectifiers and jumper and double check.

 

[punch45x2]

Is the local feedback r220 on bd card

 

[Perry Babin]

Yes.

Remove the jumper on the cap on the PS board.

 

[punch45x2]

I guess you didn't ask for output on 19

 

[punch45x2]

This is pin2 of u2000 and u2002 with cr1,2,1004,1005 center legs desoldered and jumper on r220 bd card

 

[punch45x2]

And with c118 jumper removed. But when I did that u1000 pin 2 is back down to 4v

 

[punch45x2]

See post 34

 

[Perry Babin]

You posted after I started typing. That's why I deleted the post.

Can you insert a 1 ohm resistor in series between the output pin of U1000 and the board?

 

[punch45x2]

How many watt? 1/4 or 1/2

 

[Perry Babin]

A 1w would be able to handle the full output. If you use something smaller, watch to see if it begins to overheat.

Measure the voltage across the resistor when the output is being pulled down to 4v.

 

[punch45x2]

U1000 pin 2 with 1 ohm 2watt resistor in series I have a .24 vdc voltage drop across the resistor. 4.13v output on u1000 pin2.

 

[Perry Babin]

It doesn't look like the regulator is capable of producing its rated output. It's rated for 1.5 amps and is only producing 0.24A of current. I'm assuming that it's not excessively hot.