Franc Zabkar wrote:
On Sun, 4 Mar 2012 19:47:09 -0800 (PST), klem kedidelhopper
put finger to keyboard and composed:

http://dl.dropbox.com/u/65394789/Gru...0schematic.pdf

Voltage readings
Test point Radio working: Radio not working
------------------- --------------------
E. AF178 -1.10V -1.20V
B. AF178 -1.50V -1.50V
E. AF124 -1.10V -1.20V
B. AF124 -1.32V -1.44V
E. AF121 -0.85V -0.90V
B. AF121 -1.20V -1.30V
E. AF126 (1) -1.00V -3.70V *
B. AF126 (1) -1.20V -4.00V *
E. AF126 (II) -0.80V -3.70V *
B. AF126 (II) -1.10V -3.60V *
E. AC151 (I) - 0.90V -0.80V
C. AC151 (I) --3.05V -2.95V
E. AC151 (II) --0.66V -0.62V
C. AC151 (II) --3.20V -3.10V

I suspect that C45 (near pin #8 of 7209-301) may be shorting.

- Franc Zabkar

My $0.02 worth...
Since two stages are being upset, look for what's common to both circuits.
I don't know how the PCB traces are laid out, nut since the layout diagram
indicates that both stages are enclosed by (metal?) shields, it would be
possible that the PCB trace(s) that connect the shields together might be
intermittently broken fron the rest of the circuit. That would cause the
symptom of the measured B and E voltages being high negative, indicating
that the collector circuits of both stages are open. Look for a broken trace
or solder joint somewhere in the collector circuits.

I've seen broken shielding enclosure connections cause all sorts of weird
symptoms.
--
Dave M
A woman has the last word in any argument. Anything a man says after that is
the beginning of a new argument.