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Uniden 400 fault

Posted: Sat Jan 06, 2018 11:31 pm
by TheMagnum
Hi all, I have a Uniden 400 PR27UK radio which is in excellent condition however it doesn't work. When switched on the signal meter bulb lights but no LED channel display. No sound and TX/RX lights stuck on. If I gently rub my finger over the audio IC there is a ruffling noise coming out of the speaker. If I put in the mic and TX the RX light goes out but both TX and RX lights come back on when mic depressed.

It's a different board to the basic Audioline or Uniden 100 type board, it is a PA-198 AB. Any ideas?

Re: Uniden 400 fault

Posted: Sun Jan 07, 2018 10:58 am
by stampman
first check the mic has not shorted out


*King* *King* *King* *King*

Re: Uniden 400 fault

Posted: Wed Jan 10, 2018 10:55 pm
by TheMagnum
Checked with a known good mic and without a mic. The display would come on anyway without a mic would it not?

Re: Uniden 400 fault

Posted: Thu Jan 11, 2018 9:33 am
by stampman
CORRECT hink i had this problem quite a while since and it was due to excess voltage so needs a rig doctor im afraid



*King* *King* *King* *King*