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  #21  
03-16-2019, 07:32 AM
dpalomaki dpalomaki is offline
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If the color issue goes away after some operation it sounds a bit like a failing capacitor where in it has to operate for a while with a voltage on it to reform and sort of temporarily self-heal to something close to the design value.

The capacitor problem was driven by several years of manufacturing with a bad electrolyte formula that was not stable over time. (Industrial espionage gone bad.) The failure is over time, and at different rates for individual caps.

As to time vs. cost, a shade tree auto mechanic operdting ona cash only basis might charge you $30/hour, the dealer $130/hour. The hourly rate has to cover direct labor, fringe, set-up and take-down, and overhead costs such as equipment, utilities, idle time, facility, tools, training, insurance, warranty, customer satisfaction allowance, and so on. In a commercial environment the billed cost can easily be several times the per hour salary rate of the technician.

Electrolytic caps have a tolerance that ranges 10-20%, sometimes more. Components age over time. Just replacing caps may be quick if one is experienced, but if that is all one does, and the unit still doesn't play well the customer will be upset, thus the need for a full cleaning, lube, electrical and mechanical alignment check/tweak as needed, before a unit is sent back. A fixed price means the service provide assumes the risk of a unit requiring more work. No one like a low estimated cost that then increases due to unexpected problems.

In my experience ham handed soldering on the boards can cause damage - especially boards with SMD rather than thru-hole caps. A bit too much heat and the copper trace can detach from the board. And replacing a 1/4 watt axial lead resistors in a stereo is in general a lot easier soldering task than an SMD on a tightly packed board. If embarking on a DIY project and not experienced in working with SMD boards, find a junk board on which to practice first to refine soldering techniques. And be aware of and accept the risks before you start.

When i recapped my AG1980 I measured the ESR and value of all caps I replaced. Perhaps 1/3 of the SMD (I forget the exact number now) were out of the acceptable range. A much lower portion of the conventional electrolytic (thru-hole mounted) were out of spec. I did not replace any on the main board nor did I replace any of the non-electrolytic caps.

The AG-1980 is from the industrial product line and is a much more complex beast than the consumer line. It was build to take a beating - as many have. It and did have a clear maintenance protocol specified for it that was necessary to keep it running well, something most home users would have ignored. Its main weakness was a run of relatively short life capacitors.
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  #22  
03-16-2019, 11:41 PM
RS456 RS456 is offline
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That is why I am am looking for AG-1980 for parts. If it doesn't turn out well I still have the pseudo working board.
Out of curiosity. Do medical grade VCRs have TBC built in? Reason I am asking is because when searching for other options medical grade recorders showed up. If so I actually have one.

Last edited by RS456; 03-16-2019 at 11:52 PM.
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  #23  
03-17-2019, 12:07 AM
ofesad ofesad is offline
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Quote:
Originally Posted by RS456 View Post
That is why I am am looking for AG-1980 for parts. If it doesn't turn out well I still have the pseudo working board.
Out of curiosity. Do medical grade VCRs have TBC built in? Reason I am asking is because when searching for other options medical grade recorders showed up. If so I actually have one.
I don't think that getting another AG1980 will solve your problem. Replacing caps will.
If you get a AG1980 for parts it will most probably have his caps spitting his juices out

Please be more specific: wich model, brand, are we talking? Post a picture if possible.

Sometimes some "Medical grade" VCR's were just professional VCR's.

For example the Mitsubishi MD 3000 is a Medical grade VCR with buil-in TBC and 3-D digital noise reduction and digital Y/C separation. The Sony SVO-9500, too.
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  #24  
03-17-2019, 12:18 AM
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I know the medical grade vcr I have is a Sony. I have still have to check the model number (It kind of looks like this SVO-9500MD). I was going to get the parts AG-1980 and recap that board. and put it in the working AG-1980 I have now which is a safer choice than ruining the somewhat working board if it doesn't work out.
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  #25  
03-17-2019, 12:33 AM
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Quote:
Originally Posted by ofesad View Post
Sometimes some "Medical grade" VCR's were just professional VCR's.
Usually not. These were tuned for recording, SP only, and not really playback. Above all else, these came from nasty hospital environments, and the internals were exposed to particles in the air due to the fan.

Some years ago, I bought a non-medical JVC VCR from eBay, and the model had a fan. When I got it, and plugged it in, it smelled odd in the room. A few moments later, I couldn't breathe well at all. Some sort of environmental spores had been sucked into the unit at the previous location, and then expelled when I plugged it in. I was rushed to the local clinic, where I was given a shot, and took meds for the next 5 days. Since then, I open "strange" VCRs outdoors, blow them out, brush the fan, then bring indoors. If anything looks odd, it never makes it indoors. I never want a repeat incident.

I can imagine a medical VCR would be far worse for toxins/pathogens.

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  #26  
03-17-2019, 12:56 AM
RS456 RS456 is offline
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Not to worry on that. The one I have isn't used in a hospital. VCR still looks like new an you could say I am a first hand user for it. Also I think most of my recordings are SP.
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  #27  
03-17-2019, 05:34 AM
dpalomaki dpalomaki is offline
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Medical Grade may have meant certification for electrical safety in a hospital environment, including electrical leakage (shock) and perhaps high oxygen concentration than normal air (fire hazard). It would likely have been a variation on industrial grade, but not necessarily higher video quality. One would have to read the manuals to determine whether or not is has specific TBC, noise reduction, or other features such as time lapse built in. And it likely would have been used by a wide variety of people, not just video techs.
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  #28  
03-17-2019, 06:36 AM
RS456 RS456 is offline
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I did say you could consider me a first hand user for that VCR. Only one who used it is my dad and that in his office on a regular outlet. I didn't think of it until I saw medical grade vcrs yesterday. I have to pull it out to see what features it has. All I remember is it was a Sony. You could say it is a hidden treasure I almost forgot about.
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  #29  
03-17-2019, 08:38 PM
dpalomaki dpalomaki is offline
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Several of them offered on e-bay.
Apparently has TBC and some other features.
Does not list LP or SLP/EP speeds.
Optimized for use with diagnostic equipment such as ultrasound recording and playback.

https://www.meyerinst.com/html/sony/svo-9500md.htm
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  #30  
03-19-2019, 09:24 PM
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I still have to pull that Sony medical vcr out (have to get through a lot of stuff to get it out) but I was wondering if anybody has any experience with Sony SLV-R1000? I would rather try to get AG-1980 fixed but price of Sony SLV-R1000 seems tempting if I could start with my transfers right away. How is Sony SLV-R1000 compared to AG-1980 or the other recommended vcrs?
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  #31  
03-20-2019, 07:36 AM
hodgey hodgey is offline
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I don't know anything about the quality other than that it does not have a TBC. I do remember from watching 12voltvids on youtube that many sony decks including this one have a gear that has a tendency to break though.
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  #32  
03-20-2019, 07:50 AM
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Quote:
Originally Posted by hodgey View Post
I don't know anything about the quality other than that it does not have a TBC. I do remember from watching 12voltvids on youtube that many sony decks including this one have a gear that has a tendency to break though.
No tbc? Are you sure? A lot of places equating it with AG-1980.
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  #33  
03-20-2019, 08:30 AM
dpalomaki dpalomaki is offline
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https://docs.sony.com/release/slvr1000.pdf

No TBC mention in the manual. (The APC description is not the same as a TBC.)

The comparison to the AG-1980 may be based on the SLV-1000's ability to do insert edits (it has a flying erase head) and being equipped with LANC which would allow it to be used in some linear editing environments to enable edits accurate to within few frames.
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  #34  
03-20-2019, 08:50 AM
RS456 RS456 is offline
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Then that option is ruled out.
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  #35  
03-22-2019, 05:09 AM
RS456 RS456 is offline
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Can you tell what problems these are exactly and how to fix them? I assume it might be a head problem but I am not sure.


Attached Images
File Type: jpg rainbow.jpg (70.8 KB, 14 downloads)
File Type: jpg wavy.jpg (121.1 KB, 12 downloads)
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  #36  
03-22-2019, 11:03 AM
RS456 RS456 is offline
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I forgot to mention the issues mentioned above are issues in an AG-1980 I am looking at. The subtle rainbowing is through coax and wavy picture is through S-Video and BNC Video out. The first issue (rainbow) is also present in the one I have. It is the issue I mentioned before that comes and goes as I play the tape. Any idea what these issues are called and how to fix them? You can notice the rainbowing issue in the 1st picture if you look at the white mini cape or cloak (whatever it is called).
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  #37  
03-29-2019, 01:05 PM
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I finally got a spare AG-1980. How do we remove the boards? It looks like all the smaller boards are soldered on the big board.
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  #38  
03-29-2019, 04:58 PM
dpalomaki dpalomaki is offline
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The daughter cards on the main board are generally mounted in sockets and have corresponding connectors on the daughter card. The sockets and connectors have detents/tabs on them that provide a modest interlock to prevent falling out due to vibrations. You may need to use a thin blade to free them, but use care not to break anything.
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  #39  
03-29-2019, 05:35 PM
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What is a clear indication in the playback that the capacitors have going bad or going bad? All the capacitors seem fine in the spare but the spare might have an issue with the Video output ports as it is outputting vertically interlaced video. The one I got before as I mentioned before get subtle rgb stripes that comes and goes away.
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  #40  
03-29-2019, 07:54 PM
dpalomaki dpalomaki is offline
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With my AG-1980 there were two primary symptoms of bad cap; i.e., dim display and barber pole-like interference on colors. There may have been additional symptoms but they were less obvious. Keep in mind that yours could be different.

The electrolytic caps are typically used in bypass and filter applications including power supplies. The precise visual playback image symptoms will depend on which capacitors are bad. In some cases you can spot a bad cap because the case is leaking, bulging, or split, but that covers only some cases. An in-circuit ESR tester can help identify bad and marginal caps with no obvious physical symptoms.
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