Re: Quasar VCR Model VH-420 - Testing of Power Supply?

The most probable diagnosis is high esr electrolytics in the power
supply. Don't waste your time trying to test them unless you have an
esr meter. Replacing all of them in the power supply (approx 8 - 12 )
will likely cure the problem you are having with the VCR.
electricitym
..
..
..




Peter Smith wrote:
> I'm trying to check out a Quasar VCR for a relative. The unit plays, but the
> picture is badly garbled and the flow of the tape through the machine seems
> to fluctuate every now and then. When just watching a TV channel through
> it's tuner the picture also fluctuates. I was thinking that the power supply
> was possibly going bad, how do I test it? I've found a diagram that shows
> pins 1, 5, and 6 should all show 5.1 volts, but which other pin should I
> connect to to measure the voltage? Should I pull the supply out and try to
> measure the voltage without the mainboard connected or should the supply
> have a load on it while testing?
>
> Any help would be much appreciated, thanks.

.

Relevant Pages

  • RE: An unexpected lights out operation
    ... Although my voltage does not seem to fluctuate quite so much, ... The UPS log of minor hits is quite lengthy. ... Here in southeast Texas the mains power supply is ...
    (bit.listserv.ibm-main)
  • Re: Intensity and what else affects a single ligth beams temperature?
    ... now and the voltage now to compute the power now. ... you still measure or compute the current NOW and the voltage NOW. ... Then remove phi from the calculation and demonstate ... That is going to give 100 Watts at that instant in time. ...
    (sci.physics.relativity)
  • Re: Collins 32V-3 HF Transmitter NICE!!!
    ... I think Gary Schafer's analysis is basically correct but I have minor comments to add (in addition to my earlier post, also quoted below, claiming the 400+ peak output just could not be possible, but I think I was wrong about that). ... 60 watts of audio on that final tube will at best, double the _instantaneous_ input voltage, therefore power to 240 watts which you could only attempt to measure ... amplitude, the power at this instant is four times the unmodulated, or 400 ...
    (rec.radio.amateur.boatanchors)
  • Re: Standing-Wave Current vs Traveling-Wave Current
    ... If you mean for the calculation of the voltage at 100 ns and 20 degrees down the line, ... the sine wave source voltage is zero. ... The power output from the "perfect voltage source" would be reduced below the startup output. ... How about using a perfect POWER source, ...
    (rec.radio.amateur.antenna)
  • Re: Flyback transformer design confusion!!
    ... When applying a constant DC voltage across a resistive ... load, just *how* can I increase the power into that load, other than by ... Iout is to change the resistor. ...
    (sci.electronics.design)