I would be inclined to believe that your fault is more some component(s)
became thermo sensitive. If you are prodding at the board, and there is not
intermittency, then most likely it is not a cold solder connection.
To follow this logically, you would have to use a scope while the fault is
occurring to track down where the intermittent is. Or, you can try getting
some cold spray and a heat gun, and use the technique of heating and cooling
the various components to find this.
--
Greetings,
Jerry Greenberg GLG Technologies GLG
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"hecubus" wrote in message
om...
Hi,
As the subject line states, our Technics A/V receiver is experiencing
an intermittent video condition. The unit is only 2 years and 8
months old, i.e. it's just past the 2 year manufacturer's warranty
:-(. My previous receiver, a Pioneer SX-580, lasted about 25 years!!
Anyways...
The video signal output from the RCA jack labeled "TV Monitor out" is
fine upon power-up, but after a handful of seconds, the video signal
drops out. In other words, the TV screen goes black. After a
seemingly random period of between 5 seconds and several minutes the
video signal reappears for a few seconds, and then blanks out again.
This problem occurs when the selected video source is either the "VCR
in" RCA jack, or the "TV in" RCA jack. BTW, our DVD player video
output is directly connected to the S-video input of the TV, i.e. the
A/V receiver is not used to switch the DVD video signal.
It seems the problem gets worse as the unit heats up, i.e. the
interval between when the video signal appears increases.
The audio output is fine, i.e. even when the video signal drops out,
the audio from the VCR or TV can be heard.
Given that the problem is intermittent, I assume that there is a good
probability that the source of the problem is cold solder joints. In
order to locate cold solder joints (or a bad connection in general), I
have prodded the circuit board with a wooden stick, and jiggled
various wires. As of yet, I haven't been able to isolate the supposed
bad connection.
Does anyone have any ideas or suggestions?
Is anyone aware of specific components whose solder joints seem to
have a high failure rate on Technics A/V receivers? For example, I am
aware that a large number of Sony TVs have cold solder joints on the
HOT drive transistor (and/or transformer) which eventually leads to a
blown HOT. Is anyone aware of a similiar situation for Technics A/V
products?
Thanks in advance,
Andrew