Panasonic NV-FS200 playback problem (audio)

vaccastracca · #1 09-23-2012, 06:47 AM

Hello everyone.

My Panasonic NV-FS200 Super-VHS recorder has a small playback problem from time to time, and i hope someone here knows how to fix it.

Every once in a while, there is an audio drop-out of 1 second (meaning that the audio track will be totally silent for 1 second, all of a sudden), and then everything is normal again.

It happens totally random and you cannot tell when and why. Tapes are always clean, so that's not the problem. It can do that with new or old tapes, mono or stereo and so on...On other VCRs of course i don't have this issue. Only with the Panasonic.

I cannot tell when it started doing this because I got it used on ebay a couple of years ago and it did this already (even though I noticed it only after a few months, since I don't use it frequently).

juhok · #2 09-23-2012, 11:54 AM

There can be a lot of reasons. You can download FS200 service manual from this site and start tracing. Very difficult with this kind of occasional clitch. FS200 has a notoriously bad PSU which needs replacing the capacitors sooner or later. I've had 2 such bad PSUs and the unit worked fine otherwise but video had green lines, a bit like one head would be bad. Changing PSU fixed this. Might affect audio too.

I've had two FS200's which for some reason had chipped/cracked PCB on the bottom right corner (as seen from the front side) and that killed audio completely. Dunno if this is common for FS200 or if I just had incredibly bad luck as they came from completely different sellers. Image attached.

2012-07-07-13-37-14.jpg

lordsmurf · #3 09-25-2012, 03:21 AM

The PSU also has a fuse inside that can be changed.

The most common problem with the AG-1980 (and thus FS200) is that the capacitors are all drying up right now.
Everybody's Panasonic VCRs are starting to fail. After 10-15 years, they either dry up or go too far out of spec.

vaccastracca · #4 09-25-2012, 03:42 AM

Quote:

Originally Posted by lordsmurf

The PSU also has a fuse inside that can be changed.

Where is the PSU located in the NV-FS200? Is it complicated to change the fuse? (I am no tech...i can handle basic operations but not complicated things)

lordsmurf · #5 09-25-2012, 03:48 AM

Look for a big metal-enclosed brick. Near the power plug. That's it.
The fuse is a huge pain in the butt to change -- I don't envy you right now. I hate the design of that PSU.

I doubt it's the fuse. It's probably bad caps.

vaccastracca · #6 09-25-2012, 04:52 AM

Quote:

Originally Posted by lordsmurf

I doubt it's the fuse. It's probably bad caps.

And can these parts be found normally in electronics stores or is it rare stuff?
Because i'll probably have to fix this by myself, with the help of an amateur-tech friend of mine.
The situation in Italy for "professional" repairmen and techs is pretty desolate, actually...most of them don't work anymore with old VCR's or tv's...if you bring them an old vcr to fix, first they watch you with disgust, then they put the thing in a corner, keep it for months and eventually give it back to you saying "i can't find parts, throw it away"...so if you have something to fix, you have to do it yourself!
But I guess it's more or less like this everywhere, nowadays...isn't it?

juhok · #7 09-25-2012, 08:06 AM

Locating, replicating and replacing the caps for the PSU is not a something you want to do without tech backround (be it hobby or pro). Maybe you'll friend will know how. You don't want to mess the PSU up, at worst you'll blow something up and cause a fire hazard. The PSU is the part where power cord goes in. You can unplug the module by removing a couple of screws and a few wires. I see no reason why you couldn't just give the PSU module to a shop and tell them to change the caps. Even if they don't want VCRs, changing a caps from a small PCB is an easy job for them.

NJRoadfan · #8 09-25-2012, 09:26 AM

PSUs generally have larger "hole thru" capacitors that are easy to change. Unlike the other boards in the VCR which tend to use tiny surface mount caps. Panasonic has a known reputation of capacitor problems in the repair industry starting with their 1988 models. The surface mount caps they used were under spec and subjected to high temperatures leading to early failures.

juhok · #9 09-25-2012, 10:55 AM

Easy yes, if you have the basic knowledge and skills. I've seen my mates screwing up even easier things than this - it can be done. PSU is a dangerous component to exercise with.

I may sound over cautious but better safe than sorry. And I say this with a basic degree in electronics which includes safety training.

NJRoadfan · #10 09-25-2012, 12:09 PM

What amazes me are the number of average joes buying re-cap kits for LCD TVs on the internet and successfully complete the repairs without any problems. My problem was never putting the new parts in, its getting the old part out without damaging the board. Never use a de-soldering pump.... ever. Stick with the de-soldering wick.

lordsmurf · #11 09-25-2012, 05:51 PM

Last year I tried to repair a power supply. Everything seemed fine -- until it was plugged in!

- There was a small "POP!" with a flash.
- Every breaker in the building tripped.
- And then a small fire almost started. It fizzled out as nothing more than smoke.
- The entire office smelled like burnt electronics.

Oops.

Nothing else was lost, because the PSU was being tested independent of any important hardware. When it blew, it only blew itself out. That was my first and last foray into power supply repair. Do note that this was with a computer power supply, not a VCR power supply, but the basic concepts are still the same.

Don't repeat my mistake.

vaccastracca · #12 09-26-2012, 01:34 AM

Quote:

Originally Posted by lordsmurf

Don't repeat my mistake.

That was pretty enlightning! I definitely will the PSU be touched only by a qualified tech!
Anyway, as it always happens, in these days I'm thoroughly using the VCR, and it is working flawlessly since i started this thread! ....it seems it's mocking me!

NJRoadfan · #13 09-26-2012, 10:26 AM

Quote:

Originally Posted by lordsmurf

Last year I tried to repair a power supply. Everything seemed fine -- until it was plugged in!

- There was a small "POP!" with a flash.
- Every breaker in the building tripped.
- And then a small fire almost started. It fizzled out as nothing more than smoke.
- The entire office smelled like burnt electronics.

Oops.

I'd be worried about the wiring of the building. A shorted power supply should NOT trip every breaker!

We had a few of these back when I fixed computers, the most they did was trip the breaker for the circuit they were on (as it should). Sometimes we got lucky and they only popped the breaker on the power strip they were connected to.

One thing that you have to be mindful of when replacing electrolytic and especially tantalum capacitors is polarity.... otherwise things go boom.

lordsmurf · #14 09-26-2012, 06:43 PM

I inquired about it at the time. The breakers are all AFCI and GFCI, and some of them are linked to trip together at a certain level of fault. It's intended design. Lights were not knocked out because receptacles are on separate circuits. There are two boxes, and it's more complicated than a traditional setup.

Everything checked out on my repair job -- that what never made any sense.

It's just easier to pay somebody else. My time is put to much better use than standing over an electronics bench.

Let them trip the breakers in their building, if needed!