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-   -   Panasonic AG-7510/AG-1980 Capacitor Replacement (https://www.digitalfaq.com/forum/vcr-repair/7922-panasonic-ag-7510-a.html)

cabrower 04-05-2017 01:39 AM

Panasonic AG-7510/AG-1980 Capacitor Replacement
 
Hi guys, I want to say that for you for all the valuable information you guys provide on this forum. I have a AG-5710 which I believe is in need of a capacitor replacement. I searched through the forums but didn't know if there was a list generated with all the recommended capacitors to be replaced.

I wanted to order all the capacitors prior to disassembling everything. Also I didn't know if there was any photos which point out the locations of all the capacitors to be replaced? I seen some people talking about making videos of doing it, but i didn't see anyone post any.

Any information you guys have would be great.

Thanks,
Chris

bever 04-05-2017 03:17 PM

Here you go sorry no video

not necessarily a complete list but a good start
following here is a mix of SMD caps and radial aluminum electrolytics

5-3 VIDEO (MAIN) SCHEMATIC DIAGRAM PG 50

C1002 16V47/EKA
C1004 18V47/EKA
C1007 6V220/EKA
C1013 6V47/EKA
C1015 6V47/EKA
C1098 10V220/EKA
C1099 6V100/EKA

C1812 6V100/EKA
C1814 6V100/EKA
C1816 6V47/EKA

C3016 6V47/EKA
C3030 16V10/EKA
C3031 ECEAGJU331B 6V330 ECEAOJKA101
C3032 16V10/EKA
C3033 6V1B00
C3036 6V100/EKA
C3064 6V47/EKA

C3828 6V220
C3830 16V10/EKA
C3930 16V10/EKA

5-36 ANALOG Y/C SCHEMATIC DIAGRAM

6V100 C30005
50V 3R3 330009
16V 10(b) C30010
16v 10uf c300012
16v 10 c30014
5v 4R7(B)c300015
16v 10 c30020
50v 1(B) c30027
6v 100 c30031
25v 4R7(B) c30033
50v R22 c30037
6v 100 c30039
16v 22(C) c30062
6v 47uf(C) c30070

5-22 HEAD AMP SCHEMATIC DIAGRAM

C502 6V 47/EKA
c501 6v 22/EKA
C555 6V 220 ECEAOJPK221I
C558 6V 47 ECEAOJPK4701

5-21 INPUT/OUTPUT SCHEMATIC DIAGRAM

C3986 6v 22 /EKA
c3692 6v 22/EKA
c3918 6v 22
c3913 16v 47EKA
C3921 6V 100eka
c3929 6v22

5-9 VIDEO CONTROL SCHEMATIC DIAGRAM

c6011 6v47/EKA
C6011 6V47/EKA
c6016 6v22/EKS

I am also tooling up for a cap replacement endeavor on a panasonic vcr. This one is an AG-1980 is a EBAY "find".
In the last sentence the word find may be considered the punch line.

Here is the way I am doing it.

Looked through the schematic and make note of all electrolytics that you might need. I compared that against the pars list and also against a visual inventory from the boards themselves and ordered about $60 worth of caps way more than I hope I will need. In most cases I ordered qty of 10 or 25 each for price break. The Idea is to have all the stuff I need when it goes in for surgery. Caps not used will go into stock in my vintage electronics repair shop that is opening third quarter of 2017. Most of the little SMD caps wont get used in vintage electronic but the small conventional aluminum radial electrolytics will.

Have on hand an ESD temp controlled soldering station (mine also has hot air), decent solder wick, tweezers, solder tweezers, solder sucker, Flux. I chose the flux you need to clean off vs the no clean type. Have a big magnifying light and something to hold the small boards as you work on them.

Watch several you tube videos on SMD soldering and desoldering.

Practice on some similar boards which are not too important, I have been working on two B&K oscilliscopes that are failed. Believe it or not they have caps leaking their guts out also. I have to get a feel for the temps on my iron and hot air solder melter.

Utilize an ESR type in circuit capacitor tester and also have a capacitor tester on hand to check the new caps going in and the satisfaction of proving the ones you pulled out are bad. It is my opinion that it is worth targeting bad caps detected in circuit and doing replacement first before doing wholesale replacement. It is entirely possible to induce problems in the circuit boards due to solder blobs, circuit board pad and run damage, heat etc while changing caps. less disruption the better.

Photograph boards before and after as a memory aid. polarity and values in correct location.

(I have an ace in the hole in the form of a newer 100 mhz digital scope which I can verify some basics like power supply ripple/noise and follow the signal flow to localize problem areas.)

on my want list.

NTSC pattern signal generator may be able to use a recording of a pattern for signal tracing as a workaround.

Real from the factory paper copy service manual in color if it is available so far no luck will have to work with pdf copy that I enlarge and tape together.

Let me know how your project works out cabrower. My machine is starting out with a dark barely recognizable picture and the tbc clears up the sync but makes the picture even darker.

Quasipal 04-06-2017 03:15 AM

I have just started on the rebuild of an AG8700. Was bought by a studio in the 90's and used about twice, so it is in mint condition. However the SMD capacitors are ALL bad - the smell of fish on powering up was not very pleasant and all the capacitors read so bad that my meter would not even see a capacitor in circuit. I am going to replace them all - there is no picture apart from noise and wavering bands of colour. The only card without SMD devices is the audio board - that has quality through-hole capacitors. The audio works perfectly.

Just a few comments on this subject - and this is my opinion only.

I will not be replacing the capacitors with SMD types, rather through hole with the legs formed in a suitable shape. The reason being is that some of the capacitor solder points are abutting resistors and other tiny SMD items that if they become dislodged or damages, will cause no end or headaches. Also some of the devices are under a lip of shielding cans, against the plastic body of adjustment pots etc and to apply even a dedicated tweezer iron will cause melting to some degree of these parts. I want to replace the capacitors without disturbing anything. I don't think that these boards were designed to be serviced, just replaced.

The same applies to removing the SMD caps. I realise any damage that happens when removing them will likely be the end of that board. So I have gone with the twist method of removing the old capacitors - but taking it extremely slowly. I am twisting each capacitor only around 5 degrees each way whilst pressing down. So far this has proved by far the best way (for me). No heat being applied and those pads really are not designed for being heated - they tent to 'pop' as the PCB below gasses (due to flame retardant).

I have worked as a trained audio repairer and so have some skills, but even with the correct tools (and very expensive they were) I often used manual methods of extraction over heat where I felt heat would damage a delicate area.

Anyway, just sharing - and I'll be following this thread with interest.

bever 04-26-2017 01:32 PM

Quote:

Originally Posted by Quasipal (Post 48773)

I will not be replacing the capacitors with SMD types, rather through hole with the legs formed in a suitable shape. The reason being is that some of the capacitor solder points are abutting resistors and other tiny SMD items that if they become dislodged or damages, will cause no end or headaches. Also some of the devices are under a lip of shielding cans, against the plastic body of adjustment pots etc and to apply even a dedicated tweezer iron will cause melting to some degree of these parts. I want to replace the capacitors without disturbing anything. I don't think that these boards were designed to be serviced, just replaced.

The same applies to removing the SMD caps. I realise any damage that happens when removing them will likely be the end of that board. So I have gone with the twist method of removing the old capacitors - but taking it extremely slowly. I am twisting each capacitor only around 5 degrees each way whilst pressing down. So far this has proved by far the best way (for me). No heat being applied and those pads really are not designed for being heated - they tent to 'pop' as the PCB below gasses (due to flame retardant)

Thanks for your input Quasipal. I see you have put some thought and execution into this.

Although I have been trained and certified for soldering through military and civilian aviation this is my first foray into surface mount component replacement. I dont like it and it scares me. It is (almost) as bad as changing a component on a memory stick for a PC. I have seen twist method of SMD cap removal demonstrated on you tube and it looks like it may be a good way. Also I have seen kevlar tape used to shield the adjacent components from collateral damage when using the hot air. One technique I watched or read about (cant remember) is cutting the top of the cap off to get easy access to the legs for removal with an iron. The whold mess reminds me of the old joke where you ask someone "have you ever smelled moth balls"

I ordered an MESR-100 ESR in circuit cap tester over 5 weeks ago and am stubbornly waiting for it to arrive.You could say it is literally on a slow boat from China. It is the last excuse I have before getting started.

Quasipal 04-26-2017 04:23 PM

Well I have the Peak ESR meter which also gives capacitance - got that one mainly because it was made locally and I HATE waiting!

My unit is all working now, fitted with genuine Panasonic capacitors. In the end I fitted new SMD ones simply because they were quicker than forming radial ones. But I did fit some this way, mainly the Bi-polars and a couple of odd values.

My method was:

Twist out old capacitor - no room for hot air and solder was contaminated with capacitor leaking so not melting.
Clean up pads with 25 Watt iron with tip ground to a chisel.
Dab of solder on the pads
Press down new component with a wooden stick (hold component with a tiny blob of Blu Tac)
Tack one leg with soldering iron
Drop of flux
Press down component and solder into place

This took practise, but I ended up with one removed and replaced per minute to a high standard. I had no problems at all, just time consuming. I'm glad I did not go the hot air route - may have dislodged some very tiny components abutting the capacitor solder pads.

So I can now take on any SMD job with some confidence - they are not really worse than through hole types once you get going. And getting a perfect working VCR for 'free' at the end is very heartening.

glazuna 05-11-2017 04:12 PM

Quote:

Originally Posted by Quasipal (Post 49132)
Well I have the Peak ESR meter which also gives capacitance - got that one mainly because it was made locally and I HATE waiting!

My unit is all working now, fitted with genuine Panasonic capacitors. In the end I fitted new SMD ones simply because they were quicker than forming radial ones. But I did fit some this way, mainly the Bi-polars and a couple of odd values.

My method was:

Twist out old capacitor - no room for hot air and solder was contaminated with capacitor leaking so not melting.
Clean up pads with 25 Watt iron with tip ground to a chisel.
Dab of solder on the pads
Press down new component with a wooden stick (hold component with a tiny blob of Blu Tac)
Tack one leg with soldering iron
Drop of flux
Press down component and solder into place

This took practise, but I ended up with one removed and replaced per minute to a high standard. I had no problems at all, just time consuming. I'm glad I did not go the hot air route - may have dislodged some very tiny components abutting the capacitor solder pads.

So I can now take on any SMD job with some confidence - they are not really worse than through hole types once you get going. And getting a perfect working VCR for 'free' at the end is very heartening.

I always thought if you put your mind into it you can do anything, especially if you are patient! Some people just never want to bother with anything. I am a type of person who will stick to it until finished. Most people would give up the moment it gets hard. Having gone trough computer science high school and college, we did have some soldering and quite a lot of hardware theory, so I am not exactly :screwy:
Will give this thing a shot this summer with my rtv950. Would be cool if someone could finally make a full list of all capacitors and possible pictures of where they go, apart from just the markings of them on the board.
By the way, the list on the first post has less than 100 caps listed, but people on forums are talking of 100+, 200 capacitors needing a replace:hmm:

Quasipal 05-11-2017 04:58 PM

Quote:

Originally Posted by glazuna (Post 49308)
I always thought if you put your mind into it you can do anything, especially if you are patient! Some people just never want to bother with anything. I am a type of person who will stick to it until finished. Most people would give up the moment it gets hard. Having gone trough computer science high school and college, we did have some soldering and quite a lot of hardware theory, so I am not exactly :screwy:
Will give this thing a shot this summer with my rtv950. Would be cool if someone could finally make a full list of all capacitors and possible pictures of where they go, apart from just the markings of them on the board.
By the way, the list on the first post has less than 100 caps listed, but people on forums are talking of 100+, 200 capacitors needing a replace:hmm:

Yes, putting effort in can be really rewarding and I actually really enjoy fixing things. Trouble is that so few people bother and stuff gets skipped instead.

Concerning the amount of capacitors, if the VCR has TBC cards then the amount of capacitors goes up massively. Those PCB's are packed with them!

glazuna 05-11-2017 05:09 PM

Quote:

Originally Posted by Quasipal (Post 49310)
Yes, putting effort in can be really rewarding and I actually really enjoy fixing things. Trouble is that so few people bother and stuff gets skipped instead.

Concerning the amount of capacitors, if the VCR has TBC cards then the amount of capacitors goes up massively. Those PCB's are packed with them!

One thing I would ask though. How is the access to the individual circuits, does the removal of the boards require dismantling the whole vcr (gears, belts) to the amount that it needs timing adjustments?
Talking abou the ag1980 type.

MrPete 12-22-2022 12:35 PM

For future info seekers: the list of caps on this thread contains many typos / errors. We now have a validated list at https://www.digitalfaq.com/forum/vcr...anuals-ag.html


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