Can anybody help me fix the following problem with my venerable
Panasonic
PV-4760 VCR?

All tape and tuner functions work perfectly when the dispaly stays on.
The tape path, heads, and drive belts are clean.

When the VCR is first plugged in, the display comes on and the VCR
functions perfectly. However, after typically a minute or so, the
display begins to flicker and eventually goes out --the VCR goes dead.

After the above problem occurs, the VCR can turn itself on or off by
itself, erratically.

Can anybody, please, help me fix this problem? I have basic technical
knowledge, but I am not an electronics expert, so, please, do not get
too technical. This VCR has almost everything well labeled inside, so
if
you refer to a particular item number and tell me approximately where
it is located (I do not have a service manual), I should be able to
find it.

I read somewhere that the cause of this problem may be a "transistor
C4130 (NTE 2312) 330 uf caps, 22uf cap", but I do not have a clue of
what any of these numbers/letters mean or where to find that part in
the
VCR. I trust that somebody in this forum can help.

Thank you in advance for your kind assistance in this matter.

Telly

"Telly" ha scritto nel messaggio
oups.com...

Panasonic PV-4760
I read somewhere that the cause of this problem may be a "transistor
C4130 (NTE 2312) 330 uf caps, 22uf cap", but I do not have a clue of
what any of these numbers/letters mean or where to find that part in
the
VCR. I trust that somebody in this forum can help.

They are the famous failing electrolytic caps in the Panasonic VTR PSUs.
Change all electrolytic capacitors in the power supply, this will fix your
problem !!!

I.

Dear Inty,

What a speedy reply! Thank you very much. I'll try that.

May I bother you with one more question? Does an online manual
for this VCR or equivalent exist anywhere? The power supply of the
PV-4760 seems hard to get to, and I do not want to damage something
while trying to fix the erratic display problem.

Thank you again,
Telly

"Telly" ha scritto nel messaggio
oups.com...

May I bother you with one more question? Does an online manual
for this VCR or equivalent exist anywhere? The power supply of the
PV-4760 seems hard to get to, and I do not want to damage something
while trying to fix the erratic display problem.

Do not change the whole psu. Change only electrolyitic caps in the secondary
part !

I.

"Inty" wrote in message
...

"Telly" ha scritto nel messaggio
oups.com...

May I bother you with one more question? Does an online manual
for this VCR or equivalent exist anywhere? The power supply of the
PV-4760 seems hard to get to, and I do not want to damage something
while trying to fix the erratic display problem.

Do not change the whole psu. Change only electrolyitic caps in the
secondary
part !

I.



And the 4.7uF (10 uF on some models) in the primary side.

Mark Z.

Dear Inty and Mark,

Thank you both.

Please, forgive my ignorance, but don't I need to remove the black
plastic
cage that surrounds the power supply in order to get to the capacitors?
I have
removed the top and bottom covers and the front panel, but I do not see
an easy
way to expose the parts of the power supply. That is why I thought of
asking for
the possible existence of an online service manual or equivalent --to
avoid
bothering other people with my questions.

Thank you again,
Telly

"Telly" wrote in message
ups.com...
Dear Inty and Mark,

Thank you both.

Please, forgive my ignorance, but don't I need to remove the black
plastic
cage that surrounds the power supply in order to get to the capacitors?
I have
removed the top and bottom covers and the front panel, but I do not see
an easy
way to expose the parts of the power supply. That is why I thought of
asking for
the possible existence of an online service manual or equivalent --to
avoid
bothering other people with my questions.

Thank you again,
Telly


If the power supply is not plainly seen to be removable, it must be an older
one with much more difficult access. Probably not a doit-yourself type
repair for most people.
On the older ones. the front panel must be removed, and a fairly complicated
disassembly done just to gain access. Not a big problem for a technician (
that's why we make the big money after all - NOT), but unless you've done
this sort of thing before, perhaps better left to a professional.

Mark Z.

Dear Mark,

Yes, my VCR is of the older type, with very hard to reach power
supply.
The technicians deserve every penny they charge, after all!

Having said that, and although I am not by any means an
electronics
expert, I did build a PC from scratch and worked the first time I
turned it
on, and I did manage to fix a troublesome cassette carriage (basket) on
a Sony SLV-760HF VCR. I believe that, if I had a service manual or
instructions
on how to get to the capacitors of the power supply of my PV-4760, I
would
be able to replace them. It's a spare-time challenge, rather than
desire to
save $$. I was thrilled to discover this forum and see how helpful
other people
can be.

Thank you again.

Telly

Telly wrote:
Dear Mark,

Yes, my VCR is of the older type, with very hard to reach power
supply.
The technicians deserve every penny they charge, after all!

Having said that, and although I am not by any means an
electronics
expert, I did build a PC from scratch and worked the first time I
turned it
on, and I did manage to fix a troublesome cassette carriage (basket)
on a Sony SLV-760HF VCR. I believe that, if I had a service manual or
instructions
on how to get to the capacitors of the power supply of my PV-4760, I
would
be able to replace them. It's a spare-time challenge, rather than
desire to
save $$. I was thrilled to discover this forum and see how helpful
other people
can be.

Thank you again.

Telly

Well, remove the plastic front panel, remove the screws holding the main
board to the bottom of the unit, swing the board out, and start trying to
worm the power supply out of there. The capacitors involved are mainly in
the secondary circuit of the power supply, with just a 4.7 or a 10 uf in the
primary also needing to be replaced.
They'll mostly be either 1000 uF, or 330 uF, rated either 6.3, 10, or 18
volts. There will also be one or more 33 or 47 uF caps that should also be
replaced, and maybe a 1 or 2.2 uF also to be replaced.
Being of the electrolytic type, pay attention to polarity, and be sure to
put the new ones in there the same way.

There is a small-value electrolytic on the +44 volt line which tends to hold
voltage, and you'll probably get a spark and a snap! when you find it. Not a
biggie really, but it WILL get your attention.

Post back for additional help.

Mark Z.

Dear Mark,

Thank you very much.

I have ordered the power-supply rebuild kit. As soon as I get it,
I'll go
to work and see how far I'll go without bothering you again. I'll
report back
as to what happened.

Appreciative,
Telly

Telly wrote:
Dear Mark,

Thank you very much.

I have ordered the power-supply rebuild kit. As soon as I get it,
I'll go
to work and see how far I'll go without bothering you again. I'll
report back
as to what happened.

Appreciative,
Telly

You can e-mail me direct when the time comes. A picture of the unit might
help jog my memory.

mail to:


and reverse the domain name.


later.

mz