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Winston Winston is offline
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Default Grundig AM/FM portable "Transistor 305" troubleshooting

klem kedidelhopper wrote:
I would like to ask for help once again with the repair of my own
personal old radio.


Hey Lenny,

It looks like a thermal intermittent.
Transistor AF126 is being told to 'cut off'
when the area around it heats sufficiently.
I suspect trim pot R22 (Just below AF126)
has a fractured solder joint which pops
open under thermal expansion.

Use your plastic spudger tool to gently
wiggle R22 and see if you can reproduce the
problem at will.

Next available moment, suggest you replace
the solder on R22 using plenty of liquid
RMA flux, then clean the area with naphtha
and an acid brush. Use lots of ventilation
and 'exam gloves' on your hands. Naphtha
is an excellent cleaner and will suck the
oil right out of your hands. DAMHIKT.

--Winston