Charles Packer:
The power supply rebuild kits do not necessarily "fix" all power supply
issues but they do cover some of the most frequent failure modes and for the
newbie tech that does not have a lot of electronics troubleshooting
knowledge, repair experience and component testing know-how and test
equipment, it may offer a good chance for you to repair your power
supply.... but as you pointed out you will be replacing parts that may not
need to be replaced.
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
--------------------------


"Charles Packer" wrote in message
om...
Is this repair project worthwhile, given the circumstances?

Sony VCR, model SLV690HF, died suddenly. It worked fine up until
I pushed the power switch and eject button on the front panel almost
simultaneously (I don't use any VCR much; it's my wife's
preoccupation). Now it's absolutely dead. I suspect the power
supply, perhaps a semiconductor therein, given the symptoms.

The fuse is okay, and I see that there's one 'o them newfangled
switching power supplies. My electronics hobbyist years ended
before they became prevalent, so I don't know a thing about them.

There's a lot in this newsgroup about related issues. One posting
alerted me to one other circumstance that might be relevant: It
mentioned that the power supply runs hot. In the last year, it's
been powered on more than off because I rearranged the connections
such that it has to be on whenever TV is being watched.

The notion of a power supply rebuild kit looks attractive, and I found
my way to the Web site of Studio Sound Electronics. For less than $20 for
the kit and two or three hours work, it would seem worth it to do
the repair. The VCR worked fine for eight years, and cost $270 new.

Assuming that it is the power supply, I guess I need to know two
probabilities to decide if it's worth it to order the kit and get
to work:
1. That the failed component is a semiconductor (to reduce
the number of parts I'd have to remove and replace).
2. That the rebuild kit will include a replacement for it.

On Thu, 18 Mar 2004 05:38:49 -0800, Charles Packer wrote:

Is this repair project worthwhile, given the circumstances?

Sony VCR, model SLV690HF, died suddenly. It worked fine up until I
pushed the power switch and eject button on the front panel almost
simultaneously (I don't use any VCR much; it's my wife's preoccupation).
Now it's absolutely dead. I suspect the power supply, perhaps a
semiconductor therein, given the symptoms.

The fuse is okay, and I see that there's one 'o them newfangled
switching power supplies. My electronics hobbyist years ended before
they became prevalent, so I don't know a thing about them.

There's a lot in this newsgroup about related issues. One posting
alerted me to one other circumstance that might be relevant: It
mentioned that the power supply runs hot. In the last year, it's been
powered on more than off because I rearranged the connections such that
it has to be on whenever TV is being watched.

The notion of a power supply rebuild kit looks attractive, and I found
my way to the Web site of Studio Sound Electronics. For less than $20
for the kit and two or three hours work, it would seem worth it to do
the repair. The VCR worked fine for eight years, and cost $270 new.

I'm only an electronics newbie, but I just repaired my 7 year old
Ferguson/Thomson VCR (which died suddenly, similarly to yours) by
replacing all the electrolytic caps in the SMPSU. A set of capacitors
is probably cheaper than the "repair kit" (for me, the repair kit was
~27GBP, the capacitors alone were 2.50GBP. It took me an hour to remove
and replace the 10 capacitors in my VCR's PSU).

As I'm sure you know, electrolytic capacitors can dry out and PSUs are
warm places for them to live. Also, there has been a rash of poor-quality
electrolytic capacitors over the last few years (I first heard of the
problem affecting computer motherboards).

If the capacitors don't fix the problem, /then/ think about getting the
repair kit (particularly if it includes special semiconductors). Some more
experienced hobbyists advised me to get low-ESR, high-ripple specified
capacitors. Some may also need to be high temperature capacitors. The same
hobbyists also advised me to run it on record for a few hours, then remove
the power and check to see if the picture is deteriorating (herring-bone,
lines, poor picture quality) and if any of the new capacitors are running
very hot to the touch (being careful not to get zapped, of course .

Best Regards,
Alex.
--
Alex Butcher Brainbench MVP for Internet Security: www.brainbench.com
Bristol, UK Need reliable and secure network systems?
PGP/GnuPG ID:0x271fd950 http://www.assursys.com/

On Thu, 18 Mar 2004 05:38:49 -0800, Charles Packer wrote:

Is this repair project worthwhile, given the circumstances?

Sony VCR, model SLV690HF, died suddenly. It worked fine up until I
pushed the power switch and eject button on the front panel almost
simultaneously (I don't use any VCR much; it's my wife's preoccupation).
Now it's absolutely dead. I suspect the power supply, perhaps a
semiconductor therein, given the symptoms.

The fuse is okay, and I see that there's one 'o them newfangled
switching power supplies. My electronics hobbyist years ended before
they became prevalent, so I don't know a thing about them.

There's a lot in this newsgroup about related issues. One posting
alerted me to one other circumstance that might be relevant: It
mentioned that the power supply runs hot. In the last year, it's been
powered on more than off because I rearranged the connections such that
it has to be on whenever TV is being watched.

The notion of a power supply rebuild kit looks attractive, and I found
my way to the Web site of Studio Sound Electronics. For less than $20
for the kit and two or three hours work, it would seem worth it to do
the repair. The VCR worked fine for eight years, and cost $270 new.

I'm only an electronics newbie, but I just repaired my 7 year old
Ferguson/Thomson VCR (which died suddenly, similarly to yours) by
replacing all the electrolytic caps in the SMPSU. A set of capacitors
is probably cheaper than the "repair kit" (for me, the repair kit was
~27GBP, the capacitors alone were 2.50GBP. It took me an hour to remove
and replace the 10 capacitors in my VCR's PSU).

As I'm sure you know, electrolytic capacitors can dry out and PSUs are
warm places for them to live. Also, there has been a rash of poor-quality
electrolytic capacitors over the last few years (I first heard of the
problem affecting computer motherboards).

If the capacitors don't fix the problem, /then/ think about getting the
repair kit (particularly if it includes special semiconductors). Some more
experienced hobbyists advised me to get low-ESR, high-ripple specified
capacitors. Some may also need to be high temperature capacitors. The same
hobbyists also advised me to run it on record for a few hours, then remove
the power and check to see if the picture is deteriorating (herring-bone,
lines, poor picture quality) and if any of the new capacitors are running
very hot to the touch (being careful not to get zapped, of course .

Best Regards,
Alex.
--
Alex Butcher Brainbench MVP for Internet Security: www.brainbench.com
Bristol, UK Need reliable and secure network systems?
PGP/GnuPG ID:0x271fd950 http://www.assursys.com/

Sony recommends not to rebuilt the older power
supplies, as they "blow up" again! They are very
expensive to replace, that is, if it's the module type!
Rono.

Sony recommends not to rebuilt the older power
supplies, as they "blow up" again! They are very
expensive to replace, that is, if it's the module type!
Rono.

On Tue, 13 Apr 2004 21:37:20 -0230, Rono wrote:

Sony recommends not to rebuilt the older power supplies, as they "blow
up" again! They are very expensive to replace, that is, if it's the
module type!

I can't speak for Charles, but given my VCR is nearly 7 years old, a
non-DIY repair cost of 25GBP+, a replacement cost for a new NICAM deck of
55GBP, attempting a DIY repair for 2.50GBP was the only economic approach
other than junking it and buying a replacement.

Worth a shot, and I've learnt something along the way. If there's nothing
really to lose...

Rono.

Best Regards,
Alex.
--
Alex Butcher Brainbench MVP for Internet Security: www.brainbench.com
Bristol, UK Need reliable and secure network systems?
PGP/GnuPG ID:0x271fd950 http://www.assursys.com/