Re: Sylvania/Funai TV/DVD/VCR shutdown question

From: Wild Bill (kwag98_at_usachoice.net)
Date: 06/27/04


Date: Sun, 27 Jun 2004 16:19:27 -0400

I haven't had the delightful experience of working on one of these combo
units with DVD, but have repaired a few of the TV/VCR types.

My approach would be to confirm that any power supply sources (any that are
labeled) are present, then to focus my attention on the VCR.
I suspect the unit in normal operating condition (when empty) would normally
power up when a cassette is inserted, as an auto-on/power-up feature.
Confirming that the sensor light source is present, and possibly verifying
that the sensors are changing states would be a basic check.
The mechanical parts should be closely inspected, and a check of freedom of
motion of the various parts to see that a forign object hasn't caused some
interruption and/or damage.
It's not likely that the mode switch is easily accessible, or that it can be
tested without a service manual. I generally try to avoid a
tear-down/disassembly to get a mode switch out.. instead, I try to get a
couple of drops of DeoxIT to creep into the switch to see if this will
change any of the symptoms (after cycling the mech thru a couple of loading
functions).

I'm in about the same place as you, it seems.. out of the biz for a few
years, but unable to avoid the challenge of repairs. It's good exercise for
my feeble grey matter.
Funai was decent at providing parts info and service literature years ago,
don't know about now though.

Cheers
WB
....................

"D H A C" <dont_havacow@yahoo.com> wrote in message
news:6bydnRBnQJSwHEHd4p2dnA@adelphia.com...
> This is regarding a Sylvania model SRCD227 27" combo that's about 2 years
> old. This group has helped me in the past with these combo units, I'm
hoping
> someone will recognize this problem and maybe a couple of diodes will fix
> it. I have no schematic.
> What I have is a TV that will power up. You can get an excellent (off-air)
> picture for a few seconds and then it will shut off. D2645 appears to have
> been running a little hot....not sure if this is related although the
diode
> checks good on the ohm meter. All of the other diodes in this area also
> check good with the meter and there doesn't appear to be any shorts at the
> diodes outputs. Another clue is there doesn't seem to be any power to the
> motor in the DVD player and the VCR doesn't go through it's self test when
> first plugged in.
> If anyone has had a similar problem and could make a suggestion or if
> someone has access to a schematic and would be willing to forward.
>
> TIA,
> Steve
>
>



Relevant Pages

  • Re: That Lowes flashlight, again
    ... misquote) a reference on rectification. ... power and the full wave rectified power, ... with perfect diodes, you'd have 100% efficiency, but you won't have DC ... You are mixing up voltage and power. ...
    (rec.bicycles.tech)
  • Re: That Lowes flashlight, again
    ... I think where you're confused is that you're looking at the AC input power and the full wave rectified power, ... Indeed, with perfect diodes, you'd have 100% efficiency, but you won't have DC yet! ... LEDs are constant voltage devices. ... The only reason to stack 2 or more LEDs in a generator driven application is to improve the efficiency slightly by matching the generator load more closely to its designed load and making the real rectification power a smaller fraction of the load power. ...
    (rec.bicycles.tech)
  • Re: That Lowes flashlight, again
    ... I think where you're confused is that you're looking at the AC input power and the full wave rectified power, ... Indeed, with perfect diodes, you'd have 100% efficiency, but you won't have DC yet! ... The ideal diode has a discontinuity in its resistance, changing from infinite to zero when it passes through the forward voltage threshold. ... The only reason to stack 2 or more LEDs in a generator driven application is to improve the efficiency slightly by matching the generator load more closely to its designed load and making the real rectification power a smaller fraction of the load power. ...
    (rec.bicycles.tech)
  • Re: Correct measurement of repaired Guitar Amplifiers
    ... > customer on the output power of an amp that has been fixed. ... Connect output of the amplifier to non inductive high power resistor ... > repairs so I am having to learn what seems to be more intuitive repair ...
    (alt.guitar.amps)
  • Re: Using a uC for DC-DC conversion?
    ... >with less voltage drop than the mosfet body diodes for long enough to blow the ... He had worked in surge protection for power plants... ... though and that alone might rule it out in an inverter. ...
    (sci.electronics.design)