Path: ...!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail
From: jim whitby <mr.spock@spockmall.net>
Newsgroups: sci.electronics.repair
Subject: Re: Is it a capacitor, is it a resistor?
Date: Thu, 14 Mar 2024 21:31:33 -0000 (UTC)
Organization: A noiseless patient Spider
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> I was asked to repair a Pioneer QX-949 quadraphonic tuner/amplifier.  It
> is a complex beast and one channel had gone down to almost nothing.
> Luckily the service sheet was available and I traced the fault to the
> board which houses the tone controls and filters.
> 
> The gain is in two stages with the tone controls around the second
> stage.  On one of the channels, the voltages on the single transistor
> for that stage were all wrong.  After lifting the transistor off the
> board, it became apparent that the base bias was far too high and the
> finger of suspicion pointed to the inter-stage coupling capacitor
> feeding in leakage current from the preceding stage.
> 
> I tested the capacitor, which was marked "4.7".  It read exactly 4.7k in
> both directions on an ohm-meter !!!

You have a new type of device! Save it. It just might be worth 
something... someday... maybe...



-- 
Jim Whitby


For the next hour, WE will control all that you see and hear.
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Mageia release 9 (Official) for x86_64
6.6.18-server-1.mga9 unknown
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