25-10-2013, 06:41 PM
I had a further delve into the JJ-700 this afternoon, and found that a -13v line was missing. The culprit turned out to be an o/c 330 ohm resistor (R907) on the audio o/p & PSU board. This is supplied from the main 'HT' - 28v line. A new 330 ohm 2Watt resistor has restored sound, at least on the Cassette Deck and Record Player. Haven't yet tried the radio,
but hopefully that should be O.K., too. The resistor didn't appear burnt or otherwise damaged so I'll put the set on long term 'soak' test in case the replacement fails. The cassette mechanism is still mechanically sluggish to start, probably due to it's having been stored for quite a long while in the Cellar, which, yes, does get damp.
but hopefully that should be O.K., too. The resistor didn't appear burnt or otherwise damaged so I'll put the set on long term 'soak' test in case the replacement fails. The cassette mechanism is still mechanically sluggish to start, probably due to it's having been stored for quite a long while in the Cellar, which, yes, does get damp.
