Batboard

well, my UHF MSF died.

here's the specifics...

analog C74CLB series...
TX/RX lock green
TEST steady red

station will not key with the front panel toggle switch.

upon reset (i.e. unplug it) ...

test LED blinking at a strange rate...no pattern...and station still will not key up.

over the previous 2 weeks, station did this twice before..first time a front panel reset did the trick, the second time a hard reset (unplug) did it...now it's DOA.

ideas?

please don't say "new station control board"...i know it's more than likely a logic problem!

doug

Doug
On SCM check 5 volt line with an scope for any ripple(high freq),should be flat line. Ripple causes the watchdog reset circuit to keep micro resetting hence test led stays on.
As I remember, look for 1000 uf cap(3 legs) near metal case for 5 volt switching regulator.
If 5 volts is ok,and you have access to another MSF try subbing Program Prom.

TMM