On Saturday, June 26, 2010 at 1:40:44 AM UTC-4, Allyn Oldfield wrote:
On Jun 15, 5:50*am, Chuck wrote:
On Mon, 07 Jun 2010 16:42:13 -0500, Chuck wrote:
Hello.

I used to work for an Adcom warranty station and remember this was a
common problem but I can't recall what the cure is. *If anyone has a
solution I'd really appreciate it. *Thanks. *Chuck

The problem turned out to be conductive glue on the ribbon cable from
the on-standby switch to the upc board. *It wasn't visible from the
top of the unit. *I found a pin out of the upc and noticed unusual
activity on the key lines. *This activity ceased and the unit
functioned properly when the cable from the switch was detached at the
upc board. *When I removed the switch from the circuit board, I
noticed a wisp of conductive glue at the cable end. *Once the glue was
removed, the unit functioned normally. *Chuck

Hi

Thanks for posting this thread- I just fixed a similar problem with my
adcom GTP-450, I initially thought power supply caps, but after
replacing several of the smaller caps and all the regulator output
caps I googled and found this. Eventually it turned out to be the
power switch itself in my case. A momentary power switch from an old
ATX computer case had the correct stem for the button, and the wires
from the ATX switch replace the factory ribbon cable. I unsoldered the
old switch, and held the new switch in place with some epoxy resin and
a couple of screws- good as new!

Cheers
Allyn

I also had a bad power switch on a GTP-450. It measured 275K ohms across what should have been open terminals. New switch fixed the problem.

Jeff