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-   -   Panasonic AG-1980 capacitor repair? (https://www.digitalfaq.com/forum/vcr-repair/5166-panasonic-ag-1980-a.html)

videonut 11-19-2014 09:55 AM

"If display = timer board, video card = digital + analog Y/C sections, and motherboard = main + Audio (main) + Video (main) sections in FSM speak. That is about 105 electrolyics with the power supply"
To dpalomaki, please count again. There are many types of electrolytic caps, as I am sure you already know. You should change the smd caps (also electrolityc) because they are vulnerable to heat. The 47uF ( well most of them) usually are still good, but the other ones are dry after so many years and so much use.
Onmouser you do not find all the parts and is not cheap either. Good luck finding caps made in Japan with the right size, voltage and temperature.
Cheers.

dpalomaki 11-20-2014 06:48 PM

videonut: care to share what you believe is the count of electrolytic caps (radial and SMD) in the named sections of the AG-1980?

FWIW: as I recall from earlier this year, Mouser carried just about all of the electrolytic caps listed in the FSM (or the Panasonic listed replacement for discontinued products) or an equivalent. In a few cases the specified voltage was out of stock but the next higher voltage was in stock). The exception being one special cap in the power supply listed for an arm and a leg by by some parts outlets that cater to the electronics repair trade.

What sources do you recommend that have appreciably better prices and in-stock availability?

MMIndy 11-21-2014 12:57 PM

I did it!!!
 
I plugged in my AG-1080, and it works with a nice looking picture. I did it! This middle aged housewife turned small biz owner with nervous hands and in need of bifocals did it!! I'm so excited! My husband and kids were more interested in the weird cartoon tape I found to test it than in my accomplishment, so I thought I'd share here. :D

Of course, I probably made a bunch of mistakes and other things on it will die soon enough, but for now it's working nicely. And I will begin to work on another of my AG-1080s with the same symptoms. These two both had a dark picture. One started off being intermittently dark, and only when TBC was on. Then it was always dark with TBCs, and a couple days later the picture was black with or without TBCs on. The second one went to a black picture pretty much all at once. I have a third 1080 with some interference (herringbone or barberpoling) in the picture, but it's not dark yet.

I don't have an oscilloscope, power supply, ESR meter, etc. I didn't diagnose, I just took an educated guess that Y/C pack CBA was the problem after reading lots on the internet. I bought a learn to solder kit, electronics repair book, hemostats, flux pen, solder wick, and a magnifying head lamp. I replaced all the surface mount caps (and only the surface mount caps) on that board by rotating gently with the hemostats until the leads broke. I could tell about 25% had leaked.

I posted earlier about a tight space where my solder iron would melt a nearby plastic connector. I was thinking I would have to use caps with leads in those spots. But apparently, the new caps I bought were 1mm smaller in diameter, so I managed to get my solder tip in there.

Thanks for letting me celebrate!! And I just want to say while it's apparently do-able for a novice, I had little money to spend on it, nothing to lose, time to spare, and luck that nothing else was wrong with it. Were that not the case, $275 to have someone experienced fix it all up to last seems like a good deal to me. :2cents:

dpalomaki 11-21-2014 05:25 PM

BRAVO! Congratulations!

If it works to your satisfaction any mistakes didn't matter!

videonut 12-05-2014 12:38 PM

Congrats. On the next one try go few steps further and replace also the other ones not just the SMD's. Also look for ones on the power source and the few on the display board (they go together). You only need a solder gun where you can set up the temperature, good solder, and good parts. Even if you replace only some of the bad ones, it is a good chance it will start working. I have a brand new panni that works but has quite few of the caps dried and non functional, but the picture is very good; can not tell the difference on the TV screen, unless you look into it closer with some other tools. I keep that one for proof plus it needs a lot of work to replace them all to make it perfect, and I thought at some point that someone was eager to do it for $1400, but nah...., I guess to much work and I know it is. Like I said this units were made to last and the PCB boards can take a lot of abuse. I am really happy for you.
Be safe and good luck.

dpalomaki 12-05-2014 04:22 PM

Quote:

Originally Posted by videonut (Post 35420)
... I thought at some point that someone was eager to do it for $1400, but nah...., I guess to much work ...

For $1,400 someone just might take you up on that. The going rate for the problematic sections seems to be somewhat under $300.

vidz_man01 12-05-2014 07:59 PM

Contact Tom Grant at TGrant Photo in Lodi Ohio. He has a website.

videonut 12-07-2014 12:41 PM

Thank but no thanks.
I can don it 201 % better..., I just do not have the time.
If I would trust someone to do it right is NJRoadfan, but I thinks he knows that what I am asking for takes a lot of work and time to select the right parts and is not worth for him.
Just to make sure you understand I never had one vcr I could not fix, so I do not need anybody to tell me how and what to do. I am far away from being perfect, but if I start something it has to be done right.
At the 300 rate , which actually is 199 if you look around, you get lipstick on a pig service (25-45 caps changed plus some lip service). That alone will revive your old vcr. But from that to get it rebuilt and change most of the caps takes a very long time and I bet pushing carts at wally will make you much more money.
Just my 2 cents.

digicube 09-29-2018 11:33 AM

@rumburaski Can you replace caps on an AG-DS850? How much would you charge?

lordsmurf 09-30-2018 04:30 PM

Quote:

Originally Posted by digicube (Post 56507)
@rumburaski Can you replace caps on an AG-DS850? How much would you charge?

Be sure to also PM him. :congrats:

rumburaski 10-01-2018 11:03 AM

I will thanks for reminding me.

Dthomas 10-20-2018 01:40 AM

@rumburaski and anyone else. Had a quick question about the Y/C board. Do you replace the caps in between the main Y/C board and the smaller board connected to it? If so is there a function for that wire connecting the boards other than to hold them securely together? It does not look like it is attached to any leads so I am not entirely sure if it has any other purpose.

Thanks
D

Dthomas 10-20-2018 02:49 AM

In trying to answer my question I posted above I have come across another couple of questions. I was going through the capacitor list for the Y/C board. According to the service manual the capacitors on that smaller 3400 series board are all ceramic. What I see does not look like ceramic but more SMD electrolytic.

After this i decided to look at some of the other boards and discovered 2 electrolytic capacitors on the power supply not listed anywhere. I have a 10V 1200uf at C1016 and a 16V 1800u at C1022. Are these not in the service manual because I have a service manual from an earlier AG-1980?

Thanks
D

dpalomaki 10-20-2018 07:00 AM

C1016 & C1022 are shown on the schematic diagram and the PC board layout in my AG-1980P service manual. However, they do not appear on the parts list. Probably an editing omission/error on the part of Panasonic.

The daughter board 34000 series is memory, and the caps in the C34001-C34008 are 68 pFD 50v surface mounted ceramic. C34009-C34012 part number comes up as a 0.1 mFD 16v SMD ceramic which strikes me as appropriate for its location in the schematic.

Does the wire provide a ground connection between the foils on each board?

rumburaski 10-20-2018 08:50 AM

DThomas, the general rule is that anything I remove goes back.

Dthomas 10-20-2018 11:01 AM

3 Attachment(s)
Thanks @dpalomaki I missed those on my schematics. Quick question - can you get 'can' ceramic caps or do I have something different here. Attaching a couple of pictures.

Good advice @rumburaski - is my general procedure as well - wondered more about the function of the wire for level of preciseness while working. Guess with these boards just best to treat everything as careful as possible.

I am not sure if they are grounding the boards. Attaching pics of them as well. Thanks for any and all help.

dpalomaki 10-21-2018 07:19 AM

I can't tell from the photos. Today ceramic caps tend to be SMD and look like tiny bricks, or are leaded for through hole mounting. I don't recall seeing any in cans like the small, low voltage electrolytics that come in AL cans.

FYIW, sometimes during a long production run a mfgr. may discover some small issue that is addressed by adding a component, possibly a capacitor, wire, or resistor, that is not normally mounted on the board but added as an afterthought/fix. This sort of mod might not make it to the formal maintenance manuals. It is possible that the wire you see is that but no way of telling from the photo. You could check its resistance to ground.

nobleEightfold 02-17-2019 09:55 AM

I know this thread is old but I just wanted to say thank you to everyone who posted in here. Using the information in this thread I was able to replace all the smd and radial caps on my AG-1980's Y/C board and completely restore the picture, which I had thought was gone forever.

It was a brutal and time consuming process for me as an amateur, but the picture being restored now, it was completely worth it.

So thank you all again.

digicube 02-17-2019 11:19 AM

Can you provide a list of capacitors to buy?

dpalomaki 02-17-2019 02:34 PM

1 Attachment(s)
Quote:

Can you provide a list of capacitors to buy?

Read more: http://www.digitalfaq.com/forum/newr...#ixzz5fp1wkHib
Not really. That would depend on which you caps intend to replace and may also depend on whether or not your model uses the exact same boards and components as others. We know there were variations in the Y/C board over time for example, and not all caps need to be replaced. Other posts in this thread provide more information in that regard.

However, attached to this post is a spreadsheet that was based on the parts list in the back of an AG-1980 service manual. It lists the board, value, and Panasonic part number (from the 1990s). WARNING: :warning: it could well contain some transcription errors and/or omissions. It can provide a starting point for your quest. Some parts numbers have changed since then, especially the problematic SMDs, so you will need to select a substitute part that will electrically and mechanically fit the board..


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