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10-09-2018, 01:17 AM
CZroe CZroe is offline
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In 2007 I was visiting family across the country when I found these two S-VHS players at a Goodwill: Panasonic AG-1970p and Panasonic AG-1980p. Someone donated a whole rack of high end video equipment, most of which was too exotic for me to recognize. Without knowing what they were exactly I snapped them up because they were S-VHS and I figured that the “For Commercial Use Only” stickers meant “no Macrovision.”

Anyway, I took both home in my luggage and, of course, it got inspected by the TSA. They left a nice little note and everything but it didn’t explain what they did with my receipt and extended warranty for a recent Best Buy purchase. *sigh* Ended up needing that too. They must’ve thought they were doing me a favor by throwing away a Black Friday flyer. Nothing with the video decks seemed damaged, at least.

I recall powering on one or both but I didn’t really try to use them until recently. That’s when I dragged one out of storage only to find out that the 1970p shuts itself off after a second or two. I haven’t been able to connect up the 1980p yet but it I did power it up to see that it has a very dim, almost completely invisible display (unlike the 1970p).

OK, to be more specific about the 1970p, it comes on and blinks “12:00,” but hitting power causes it to make some mechanical noises, then the power light goes off and it returns to the blinking “12:00.” Well, after doing that a few times it stopped trying whatever mechanical thing it was trying to do because now the power light just comes on for a second and goes off, returning the display to the blinking “12:00.”

The 1980p coaxial jacks are a strange threading I’ve never seen before. The standard F-type coaxial jack just doesn’t fit the threads. The dim display definitely isn’t flashing 12:00 like the 1970p does. Should it?

I’m no stranger to DIY recapping jobs. In fact, I’m in the middle of doing a Pioneer LaserActive with SEGA PAC for a friend and I do work like this routinely:
https://youtu.be/0maQnu2AjnM

With a desoldering gun and hot-air station with PCB pre-heater, I’m well-equipped for replacing the capacitors but it still looks like a daunting job so I’m hoping to find shortcuts. Does anyone have a BOM for the caps on either model? Would any of the established repair shops sell cap kits? Has anyone made capacitor maps?

I’ve gleaned that the 1970p has better caps than the 1980p. Does this mean I might be able to get away with replacing only some known-problematic caps?

Lastly, I kept both all these years because I thought they were a pair (editing player and editing recorder). I now realize that the 1980p is an upgraded model. If the 1970p is easier to fix due to having better capacitors, then I’m sure it’s more than enough VCR for me. Should I even bother recapping the 1980p? I see where the FAQ says not to throw it away but there’s no way I can afford to pay several hundred dollars to repair a deck Indont even need. Do the repair shops offer trades or buy broken units?

Thanks in advance for any questions you can answer!
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  #2  
10-10-2018, 03:58 PM
dpalomaki dpalomaki is offline
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I believe the 1970 does not routinely have capacitor problems. What you describe may relate to the tape transport having issues. Does it have a tape stuck inside by any chance?

The 1980 has the capacitor issues, and the dim display is but one symptom. The Y/C board and display (timer?) board were the primary areas needing repair. It may not be necessary to replace all caps in the beast, with luck only SMDs on the problem boards. I do have a spreadsheet with a cap listing somewhere, but I am on travel for a week or so and do not have it at hand. (The SMD cap problem is rumored to be a result of failed industrial espionage caper wherein a defective formula for electrolyte was stolen and used.)
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10-11-2018, 07:00 PM
CZroe CZroe is offline
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Quote:
Originally Posted by dpalomaki View Post
I believe the 1970 does not routinely have capacitor problems. What you describe may relate to the tape transport having issues. Does it have a tape stuck inside by any chance?

The 1980 has the capacitor issues, and the dim display is but one symptom. The Y/C board and display (timer?) board were the primary areas needing repair. It may not be necessary to replace all caps in the beast, with luck only SMDs on the problem boards. I do have a spreadsheet with a cap listing somewhere, but I am on travel for a week or so and do not have it at hand. (The SMD cap problem is rumored to be a result of failed industrial espionage caper wherein a defective formula for electrolyte was stolen and used.)
There is no tape stuck in the 1970p, but after unplugging it and pressing Power it was making some mechanical sounds before the light would go off. Now, after triggering that several times, the light just comes on and goes off a couple seconds later without making any sounds. I definitely think you’re on to something!

I had set a Commodore 1702 on top which may have sagged the top a bit unless that happened with the previous owner. The top shell had a very slight bend right over the moving frame that tapes slide into but I took it all apart and made sure it was pretty straight. It looked *slightly* bent before I straightened it but it didn’t look like it could catch on anything anyway, especially since there wasn’t a tape inside.

Thanks! If you could find and share that spreadsheet it would be a huge help... and no hurry. I mean, I’ve waited over a decade to even try using these things so I think I can wait a little longer.

Yeah, capacitor plague is the bane of my existence. I just got finished recapping two Game Gears this morning, only one successful so I’ll be transferring it to a third unit. I’ll be recapping a Turbo Duo later today so, yeah, I’m definitely no stranger to this stuff! I can’t say I’m looking forward to a huge job like the 1980p but I certainly won’t let it go to waste.

The espionage incident was supposedly because they only stole half of a Japanese formula that did not include the stabilizers. It was supposedly stolen by Taiwanese manufacturers for Taiwanese and Chinese production. What few will tell you is that the Japanese were reformulating for RoHS compliance and that even the stabilized Japanese caps are grossly inferior to what we had before RoHS. The Pb-free initiative that was also part of RoHS directly led to billions of dollars of failed laptops, game consoles, TVs, and graphics cards. The XBOX 360 debacle alone cost Microsoft BILLIONS!
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10-12-2018, 07:11 AM
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lordsmurf lordsmurf is offline
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Yep, caps was espionage. BadCaps.net had lots of info at one time, still might.

My Game Gear has bad caps, too. I could never solder well, and then MS ruined my fine hand motion in 2012, so I won't even attempt it. Too tiny. I've been looking for somebody to fix it for me for probably 3-4 years now. Can you do it? My screen is perfect, zero scratches, my main worry. Body of unit still looks new, I took care of my stuff.

I don't think the 1970 has any fewer problems than the 1980 in terms of caps issues. There are fewer 1970, due not only to age, but the fact that the 1980 had a long model life of 10+ years, final Panasonic S-VHS.

The 1980 main caps issue is the one affecting the TBC. It starts being dimmer/brighter, then all hell breaks loose within 6 months, total signal loss.

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10-13-2018, 08:47 AM
dpalomaki dpalomaki is offline
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The SMD capacitor problem messed up a Shure LX wireless system I was using. It was bought in the late 1990s. The bad caps were in the compander circuit of the receiver resulting in groslys distorted output. Once the caps were replaced (about 5 years ago) it worked OK again. I think bad caps also caused issues with the viewfinder displays of many camcorders (e.g., some of the old Canon Hi8 units) - loss of contrast was one symptom.

The 1980s display board includes a voltage multiplier to drive the display digits. I believe the bad caps on that board caused the gradual loss of brightness in the display over time. Recapping that board solved that issue.

I will look for the caps listing file when I return home. Did you read through the long old thread on AG-1980 repairs?
http://www.digitalfaq.com/forum/vcr-...ag-1980-a.html
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10-13-2018, 11:04 AM
CZroe CZroe is offline
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Quote:
Originally Posted by lordsmurf View Post
Yep, caps was espionage. BadCaps.net had lots of info at one time, still might.

My Game Gear has bad caps, too. I could never solder well, and then MS ruined my fine hand motion in 2012, so I won't even attempt it. Too tiny. I've been looking for somebody to fix it for me for probably 3-4 years now. Can you do it? My screen is perfect, zero scratches, my main worry. Body of unit still looks new, I took care of my stuff.

I don't think the 1970 has any fewer problems than the 1980 in terms of caps issues. There are fewer 1970, due not only to age, but the fact that the 1980 had a long model life of 10+ years, final Panasonic S-VHS.

The 1980 main caps issue is the one affecting the TBC. It starts being dimmer/brighter, then all hell breaks loose within 6 months, total signal loss.
Thanks for the info. I’ll get it all connected again and see what else works before I take a crack at the 1980p. Even without knowing anything else about it, a 10+ year product cycle tells me they were doing something right with this model, regardless of the caps issue.

I noticed that the threading on the coaxial RF connectors on the 1980p uses a different threading from standard. I actually do intend to use RF with this for capturing from some old RF-only devices. What is this type called? Would you know where I can find adapters? Not talking about the BNC connectors they use instead of RCA Cinch. Talking about the F-type used for 75-ohm cable/antenna. The 1970p uses standard F-type.

Sorry to hear about the health issues.

Regarding the Game Gear:
Sure! I’d be happy to do the caps if you are comfortable sending it. I’ve got at least 5 more (yes, five) to recap so I’ll be doing enough to batch them and do them all at once. I’ve been following a lot of repair discussions and I still cringe when I see someone flip a system over on a hard surface to get the screws out. Rest assured: I don’t do that!

My personal unit was in nearly new condition from an estate sale and you could tell that the previous owner really cared for it. The official case was full of official accessories, games, and manuals and the handheld looked like it had barely been used (though the collection says otherwise). It was the oldest unit too (flat screen cover; no patent numbers on the back) and I feel obligated to continue treating it just as well as the PO.

One of my pet peeves is seeing shops slap a big sticker on a paper box or label that somehow survived for decades before they got their grubby hands on it. It usually damages or destroys the stuff they carelessly put it on. I’d be totally ashamed if I ended up unnecessarily putting more wear and tear on something than it had experienced in decades prior.

Oh yeah! Looks like I did manage to fully restore both of those from the other day:
https://imgur.com/a/hr9zOy6

I found a via on the audio board that had no continuity with the capacitor above it. A quick jumper and it works great now.

Quote:
Originally Posted by dpalomaki View Post
The SMD capacitor problem messed up a Shure LX wireless system I was using. It was bought in the late 1990s. The bad caps were in the compander circuit of the receiver resulting in groslys distorted output. Once the caps were replaced (about 5 years ago) it worked OK again. I think bad caps also caused issues with the viewfinder displays of many camcorders (e.g., some of the old Canon Hi8 units) - loss of contrast was one symptom.

The 1980s display board includes a voltage multiplier to drive the display digits. I believe the bad caps on that board caused the gradual loss of brightness in the display over time. Recapping that board solved that issue.

I will look for the caps listing file when I return home. Did you read through the long old thread on AG-1980 repairs?
http://www.digitalfaq.com/forum/vcr-...ag-1980-a.html
Thanks. I have been making my way through it but I thought I’d start this thread since I also had a 1970p and wasn’t sure which one I should focus on.

Glad you were able to get the Sure LX wireless system working again. The problems seems to be with most anything using electrolytic caps, whether the are SMD or THT. Unfortunately, you can’t always use ceramic anywhere the original device used electrolytic, especially for audio applications. Faded displays, low/silent audio, and certain power issues almost always point to bad caps. It really is a plague on our electronics!

Last edited by CZroe; 10-13-2018 at 11:23 AM.
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10-20-2018, 07:35 AM
dpalomaki dpalomaki is offline
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Quote:
...The problems seems to be with most anything using electrolytic caps, whether the are SMD or THT...

Read more: http://www.digitalfaq.com/forum/vcr-...#ixzz5Ttrpt9kq
I think it relates more to the specific manufacturers and mfgr dates of the capacitors involved, with SMD being more problematic. I have many devices from that era, and older, with electrolytics that work OK, they are not plagued with cap failure.

FWIW tantalum electrolytic caps from the 1970's era had problems as well. I have a Heathkit oscilloscope that had several in the vertical input amps fail. I would hear one "pop" and the display would die.

-- merged --

The attached spreadsheet is a manual copying of the electrolytic capacitors from the parts list in the back of the AG-1980P service manual.

The parts list did omit some parts, and there were some minor variants of the boards over the production run, so it is at best a starting point. For example, in a recent AG-1980 thread post it was discovered that C1022 and C1016 on the power board were not in the manual's parts list.

The Panasonic capacitor part number was from the manual, and many have been discontinued (for good and sufficient reason, they were prone to failure) under that part number, so you have to find an equivalent replacement.

Then I re-capped several years ago I ordered the parts from Mouser Electronics. You may find it lower net cost to buy more of of an item than yo need for the quantity price break.

I did not need to replace any on the main board, audio boards, or the I/O board. the Timer and Y/C boards were my issues, but your case may be different.


Attached Files
File Type: xlsx AG-1980_caps.xlsx (25.3 KB, 23 downloads)
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