On Apr 18, 3:58*am, Markus Wolfgart wrote:
Dear OM's

I'm looking for some help concerning a defective driver pcb for a
yig oscillator inside the mentioned device above.

see link: (http://www.mikrocontroller.net/topic/215840#2149959)

I'm looking for the proper value of the destroyed resistor ( 50 ohm) in
the lower corner as well as for the value of the capacitor.

Have any of you a link to the service schematic of the mentioned driver,
or could send me a copy of it.

Any help would be appreciated.

vy73

Markus
alias
DL8MBY

A bit more on this: tantalum caps have a bad habit of shorting out.
I can see from your posted pictures of the board that the burned axial
lead component is in series from pin 8 of the connector, which from
the partial schematic someone else posted to the thread is the +15V
supply. I can't quite trace out where the other end of the burned
component goes, but if it goes to that burned tantalum, then it's
reasonable to suspect that the capacitor shorted and drew enough
current through the axial lead component to burn up both itself and
the axial lead part, and that may be the extent of the problem. If
the axial lead part really was a resistor, it was probably a pretty
low value, as you suggest, and the value is probably not at all
critical. Is there any chance it was instead a low-value inductor?
You might trace out where that +15V power is used. It may help to
know that the 1826-1149 is an OP-07 op amp. If the tantalum is a
power supply filter cap (pretty likely), you'll of course want to use
one rated at least 25V on a 15V bus; 35V would be even better. These
days you could likely just use a ceramic to replace it...we have a lot
less trouble with ceramic shorting than with tantalums.

Cheers,
Tom