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Vintage Television and Video Vintage television and video equipment, programmes, VCRs etc. |
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13th Sep 2021, 8:45 pm | #1 |
Pentode
Join Date: Apr 2011
Location: Bromley, Kent, UK.
Posts: 234
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Panasonic AG-MD830 dreaded capacitors
Hi, I’m wondering if anyone has experience in replacing the surface mount electrolytics on these? This model uses several hybrid modules, which have capacitors either underneath or on the hybrid itself, which is especially difficult. Give the number of capacitors involved and the complexity of the replacement, I think I’m just going to keep this compact machine as a tape winder (mechanically it’s fine).
I have attached some pictures of the boards, showing the capacitors. It’s a shame the hybrid modules aren’t socketed. One of them looks like it could be, but unfortunately it isn’t. I have re-capped other Panasonic models, such as the AG-8700, but as far as I remember, there were no hybrid modules to deal with. Retrotechie |
13th Sep 2021, 10:34 pm | #2 |
Heptode
Join Date: Jan 2007
Location: Luton, Bedfordshire, UK.
Posts: 891
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Re: Panasonic AG-MD830 dreaded capacitors
If the machine is not being used for any specific purpose, or is not of any sentimental-type value, I wouldn't bother. It's a LOT of work!
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14th Sep 2021, 2:50 pm | #3 |
Dekatron
Join Date: Apr 2005
Location: North Wales, UK.
Posts: 6,925
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Re: Panasonic AG-MD830 dreaded capacitors
It looks a horrible job. Back in the day, of course, you just ordered a hybrid module. Trouble is even if you found a new old stock one today the capacitors would still be suspect.
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14th Sep 2021, 3:36 pm | #4 |
Nonode
Join Date: Aug 2015
Location: Cambridge, Cambs. UK.
Posts: 2,198
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Re: Panasonic AG-MD830 dreaded capacitors
Your photos give me an unpleasant feeling of deja vu from encountering a similar challenge with those Panasonic surface mount electrolytics on a Philips digital 'scope - so even larger in scale. I recall losing the will to live after changing around 100 of the things and seeing no visible improvement in the fault symptoms. I found myself wondering just how many of the decouplers were *really* necessary and which were thrown in by the designers because it was just standard practice.
i concluded that the fault lay elsewhere in the circuit and ended up giving the 'scope away through this forum. I remain uncertain whether or not I was doing the recipient a favour. How confident are you that the fault lies with those capacitors? Martin Martin
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15th Sep 2021, 10:18 pm | #5 |
Pentode
Join Date: Apr 2011
Location: Bromley, Kent, UK.
Posts: 234
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Re: Panasonic AG-MD830 dreaded capacitors
Hi Martin, the fault is a very noisy playback picture, almost as if severely off track or even playing a blank tape. Years of experience with this capacitors and that most of them measure bad on an ESR meter, tells me that they need replacing, and all of them to be sure and ensure reliability. Panasonic actually made capacitor kits for the AG-8600/8700 series, but they were easier to work on and didn’t have these awful hybrid modules (that I remember).
As the machine is mechanically fine, I’m going to use it as a tape winder and maybe even modify it with some pellon cloth rollers, so it can clean tapes too. I tend to use a machine with a built in TBC for transfer, such as the NV-FS950. |
15th Sep 2021, 10:39 pm | #6 |
Nonode
Join Date: Aug 2015
Location: Cambridge, Cambs. UK.
Posts: 2,198
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Re: Panasonic AG-MD830 dreaded capacitors
A sensible decision to be sure. My Panasonic surface mount capacitors measured badly too. I tested the instrument after each capacitor change, but it was disheartening not to see the slightest improvement after replacing so many.
Even taking great care, it was too easy to damage PCB tracks in the course of the work. At the time, I was guided by a couple of threads on other forums, but I noticed that in the end they kind of……..tailed off! Sometimes life’s just too short to spend our days on stuff that just doesn’t want to be repaired……….. Martin
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16th Sep 2021, 1:13 pm | #7 |
Octode
Join Date: Sep 2020
Location: Thetford, Norfolk, UK.
Posts: 1,741
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Re: Panasonic AG-MD830 dreaded capacitors
Oh yes. I recapped a few of these a long time ago. Very time consuming indeed.
Mind you - the biggest recap I have ever done, was replacing surface mount electrolytic capacitors in a Calrec broadcast sound desk. A total of 3000 overall! Took six months. |
17th Sep 2021, 9:19 am | #8 |
Octode
Join Date: Feb 2006
Location: Bristol, UK.
Posts: 1,042
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Re: Panasonic AG-MD830 dreaded capacitors
I have a Panasonic editing VHS that didn't work correctly. In the end I changed all the surface mount caps on the boards. My technique was to break the old caps off leaving the legs soldered to the board then unsolder the legs. New electrolytics were then soldered to the pads. In all I changed a 'lot' of caps and ended up with a working recorder. The whole job took me several weeks of a few caps at a time. I changed 5 caps then checked for any improvement. For a long time there was no change, then after one change I got a noisy locked picture, so I pressed on and finally I got a good stable picture. It seems that only one or two caps were responsible for the poor picture but finding them would have taken longer than doing a blanket swop.
Malcolm |
22nd Sep 2021, 4:37 pm | #9 |
Pentode
Join Date: Jun 2008
Location: Northern Ireland.
Posts: 158
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Re: Panasonic AG-MD830 dreaded capacitors
I have done a few of these! I would always heat it all up with the hairdryer to ensure that it was the caps and that it would give a good result. I remember getting away with leaving the old hybrid things. You can remove and heat one board at a time to find the worst and do it first. I would always use good 105 degrees standard wired caps, those surface ones are rubbish.
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22nd Sep 2021, 6:00 pm | #10 |
Dekatron
Join Date: Jun 2005
Location: Warnham, West Sussex. 10 miles south of DORKING.
Posts: 9,147
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Re: Panasonic AG-MD830 dreaded capacitors
I had the same problem with a JVC camcorder dating from around 1989 bought at considerable cost new.
It was not used for about 2 years and after being stored in a dry warm atmosphere discovered that it was completely non functional. I opened it up to discover a strong vinegar smell and most of those nasty caps leaking over the boards destroying the camcorder completely. I dropped in into the recycle bin and purchased a tiny Toshiba camera. The tiny battery lasts for ever and the movie quality excellent and that was a while back. It cost £99.00 £800 less than the original JVC! John. |
23rd Sep 2021, 2:38 pm | #11 | |
Heptode
Join Date: Jun 2005
Location: Sunderland, Tyne and Wear, UK.
Posts: 661
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Re: Panasonic AG-MD830 dreaded capacitors
Quote:
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