[TechAssist] One for the books !
- From: "Keith Trumbla" <keith@xxxxxxxxxxxxxxxxxx>
- To: <techassist@xxxxxxxxxxxxx>
- Date: Fri, 5 Dec 2003 10:58:17 -0600
Pioneer A/V surround receiver model # VSX-D307 . Problem : In the front left
channel audio was very distorted. Injection of sinewave showed that the
negative going portion was clipped off completely. Checked my rail voltages
to the PAC007 IC's and everything looked good. Sinewave going in was good
too. Ordered a new PAC007 ......didn't fix it. Really pulled my hair out on
this one. Turned out, an incorrect value resistor FROM THE FACTORY had been
installed at location R483. Schematic called for 1.8k and unit had a 47k in
it's place. Parts list didn't even list this part. It is part of the
constant current source for the negative going amplifier inside the PAC007
location IC402. Here is the kicker : in the other channel, the part in the
same location, doing the same job in the circuit, is a 47K ! And that is
what the schematic calls for ! Yes it is the same PAC007 and ALL of the
peripheral circuitry is the same. Go figure ! Anybody seen this before ? Or
am I going nuts ?
Keith Trumbla
BEM Electronics Inc.
Suite 212-530 Century St.
WPG. MB. R3H 0Y4 Canada
Ph.204.775.2875 Fax.204.774.9192
www.bemelectronics.com
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