Yeah, that's a problem with it. Nobody gets too upset on here, but on
some groups they get *really* arsey if you do it. Top posting can
sometimes confuse a thread, especially when specific questions are being
answered, and the majority are posting one way, and someone is posting
the other ...

As to your question, I would expect that the standby supplies for the
system control micro are derived from the switcher, but I couldn't say
for sure. It's been a while since I did any work on any VCRs, Sony
included. Knowing what the ESRs of the original caps should be is not
really an absolute. As I have commented a number of times with regard to
using ESR meters, a lot of it is intuition, with the meter just acting as
a backup. In general, the smaller the value of the cap, the higher its
ESR will read on a meter. The small ones, such as your 4.7uF, should not
read higher than a few ohms. 47uF up to say 220uF should not be higher
than a couple of ohms. Above this capacitance value, ESRs will generally
be in decimals of an ohm, and a factor of 10 lower than that for the
'big' values of 2200uF and up. In general, the higher the voltage
working, the lower the range of ESR values that would be 'normal' for any
particular cap. Usually, if a cap has reached a point where it is causing
trouble in a switcher, its ESR value will have gone off with the fairies,
and be easily spotted as the bad one. Interestingly, its capacitance
value will often read near enough correct on a C - meter.

What your remaining problem is, I really don't know without looking at a
schematic for the power supply, but one thing I would say is that it
seems odd that you have managed to cure the primary problem with
replacing whichever cap it was amongst the ones that you changed, and
then been left with this slightly 'odd' problem. A faulty cap is a good
call for the original problem, and was almost certainly the correct
diagnosis, but it is very rare, when this is the case, for there to be
any other issues. If it were me, I think that as a first move, I would go
over all my work again very carefully, making sure that I had got the
right values in the right places (for that you would need a schematic),
and that I had not accidentally put any in backwards (easily done :-\ ).
Also, make sure that the replacement types are 'suitable' i.e. the
correct or very close value, similar voltage working, low ESR type. They
should also be 105 degree or better types for future reliability. Also, I
would not trust any caps that you have had lying around in a drawer for
years, or any radial leaded types as being suitable.

Stating the obvious maybe, but also be sure that your soldering is all
good. If it's not something which you do all day, it is easy to get a
poor joint on a component, without realising it ...

Arfa

I'm going to tear it apart again. I will check the cap's polarity, but I
am not expecting I messed that up. I did draw a diagram before removing
the original capacitors so I think I have the right capacitors in the
right holes. I did substitute one value, I think a 100uF for an 82uF. I
tried to buy duplicate values so worse case I can try a 2nd version of the
replacement capacitor. I will reflow all the solder too... I'm pretty
good at seeing a bad joint, but I've been bitten by that before too.

Thanks for all your help... This would be so much easier if we just had a
schematic or a similar schematic to get an idea from

-Greg


100uF subbed for 82uF will not be a problem.

Arfa