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Success Stories If you have successfully repaired or restored a piece of equipment, why not write up what you did and post details here. Particularly if it was interesting, unusual or challenging. PLEASE DO NOT POST REQUESTS FOR HELP HERE!

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Old 3rd Jun 2024, 3:04 pm   #1
vidjoman
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Default JVC HR-S 5800 S VHS Recorder

After approximately 14 years I decided to take out my JVC Super VHS player from storage, where its been sitting in its box at the back of the workshop. I thought it was time to copy the dozens of mini-S camera tapes into a digital format using an adaptor to allow the playing of mini tapes on a full-size machine. I've had the machine from new and bought it almost immediately S Video machines became available in about 1990, so it's 34 years old. It had a hard life of 3-4 hours a day for the 20 years or so before it got packed away before a house move.

I was expecting there to be some problems and so the first task was to look at the switch-mode power supply. To my surprise everything in there appeared to be good. All the caps were almost spot on for value and low ESR. It was clean with no sign of any part having overheated.

The mechanics looked very clean and tidy and the only belt, toothed, was fine. I cleaned the heads and guides as a matter of course as it had been boxed up for so long. Operating the deck by hand suggested that it should work as no dried-up grease was apparent. Put a set of 4 AA batteries in the remote as I had taken the old ones out many years ago.

Time to give it some power and see what happens. Brief check of the main voltages from the power supply and they were all good. It functioned correctly with a dummy cassette so time to try a full-sized tape to test the picture. Worked almost perfectly except for a slight jitter at the bottom of the picture. Thinking back, it did that after fitting new heads and it was attributed to the lower drum being slightly worn.

This has been a very nice surprise as we hear of so many consumer products that fail even after a short time left unpowered.

Now to copy about 40 x 45-minute tapes. That’ll keep me busy for a while.
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Old 4th Jun 2024, 10:54 am   #2
williamsunique
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Default Re: JVC HR-S 5800 S VHS Recorder

I am always curious as I have seen this or similar many times before.
"All the caps were almost spot on for value and low ESR." Surely you would need to remove any electrolytic capacitor to check it's value and ESR. Heating the capacitor with a sodering iron will temporarily restore values and then measuring it will give one a false reading as to it's reliability.
I would think it would be far better having removed any electrolytic to just replace it with a new capacitor of the correct value but rated at 105c.

Paul
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Old 4th Jun 2024, 2:45 pm   #3
vidjoman
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Default Re: JVC HR-S 5800 S VHS Recorder

True that to get an exact reading from a cap or a resistor you need it isolated from the rest of the circuitry. However as a repair person with almost 70 years experience you get a feel for what value to expect and anything way out would be investigated. I know it's not 100% accurate but it's usually close enough for a general opinion of what might need checking or changing. Just changing parts, hoping to cure a problem, is not a satisfactory way to service an item as a customer will not want to pay for the 95% of unnecessary parts fitted and time taken to change them.

If it's your own item and you are prepared to spend a lot of money and time, regardless of necessity, then that is up to you.

I've just done a quick count of the caps in this machine from the service manual - Almost 700 caps are fitted of which about 273 are Electrolytics. That's a bit over the hours work that it took me to get it running.

I've left it switched on since I did it and checking a few voltages today has shown it has improved. The 12 volts expected from the power supply is now 11.98 whereas it was 11.81 before.
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Old 4th Jun 2024, 7:58 pm   #4
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Default Re: JVC HR-S 5800 S VHS Recorder

Oh well in the 55 plus years I have been repairing stuff both professionally and as a hobby I also have a feel for what goes wrong and what doesn't. Certainly electrolytic capacitors in an enclosed chopper power supply which runs hot do go wrong especially the low value 1uF or 2uF 450 volt working on the primary side of the chopper transformer. When this becomes faulty it can also damage other components. It is a must that it is changed. The electrolytics on the secondary side also cause problems, for reliability these should be changed.
Anyway all well and good with you as you are not repairing this for anyone but just using it for yourself.
It's a pity though with your experience you haven't sorted out the jitter at the bottom of the picture.
As for the 273 other eletrolytics you mentioned I agree as these are not known to cause any problem then there would be no point in changing them.
But to change the power suppy capacitors would cost pence and take about 15 minutes.

Paul
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Old 4th Jun 2024, 9:27 pm   #5
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Default Re: JVC HR-S 5800 S VHS Recorder

Any surface mount electrolytics in something of this age would concern me, they can leak & make a right mess of boards, corroding the fine traces. I seem to remember someone on here doing a complete recap of a pro-VHS machine, with hundreds of those horrid SMD caps.
Other than those, look for anything else showing signs of corrosion and I would do a recap of the PSU at least, YMMV.

David
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Old 9th Jun 2024, 6:14 pm   #6
HamishBoxer
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Default Re: JVC HR-S 5800 S VHS Recorder

My ESR meter, kit from Australia many years, reads fine for in circuit caps, one exception back then, was a certain model Amstrad sat box psu.
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Old 11th Jun 2024, 8:00 pm   #7
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Default Re: JVC HR-S 5800 S VHS Recorder

It was the 1uF on NatPan vcrs that failed after unplugging, on a certain Amstrad sat box , unplug and total psu re build. Good earner when the decorator came.
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