Neumann U473 Power problem

[timtom]

One of my Neumann U473 compressors stopped working.
I checked the voltages and the normal 20v are only around 3v.
I recapped it but still the same problem.
T10 (2n6125) gets hot when plugged to 24V.

Is there a way to check with part of the power supply is causing that problem?

 

[timtom]

I desoldered T10 and checked it with a multimeter. It has a short between E and C. As the 2n6125 is obsolete, which transistor is a good replacement? Any experiences?

 

[abbey road d enfer]

This is contradictory. If T10 is shorted, it should let pass the full 24V. Have you checked diode D18?
Anyway it suggest a short in the ciruitry; hard to say where, though.

 

[Khron]

Could C26 (also) be shorted? Or something else down the line...

 

[timtom]

This is contradictory. If T10 is shorted, it should let pass the full 24V. Have you checked diode D18?
Anyway it suggest a short in the ciruitry; hard to say where, though.

I measured 23v after the diode D18. I will search for shorts in the power supply.

 

[timtom]

I replaced the T10 (2n6125) with a TIP 32C and replaced 2 more tantalum caps connected to the power rails and the second pcb and it works again.Thanks for all the help.

 

[jensenmann]

Better recap the whole thing, esp. the tantalums. I´ve had 3 473s in the past and at some point each of them had problems, all tantalum related.

 

[timtom]

Thanks. Basically they are all replaced now. Just missing the 1uf ones cause I need to order them.