AG-1980P/5710 owners: what caps in your head PCA c55, c58?

[MrPete]

We've got an interesting curiosity going.

Two capacitors in these VCR's, popular here at DigitalFAQ, are rather unusual:

• The documented parts don't exist, and Panasonic believes they never did.
• The actual parts in my 5710 are clearly from Panasonic, and have a series code that's unrecognized.

My question: if you own one, and/or have photos, are your caps same or different from mine?

• Perhaps yours has a substitution that was made at some point
• Or, perhaps they used these special caps quite a bit but more sleuthing needed to know what they really are!

My head PCA is VEP05202 H-1 (??date code?? 8911KR1)

The two caps in question:

• Lower left corner: c58, bright blue, 4mm diam, 7mm long, unique mark is [M] CE 85°C
• Upper center: c55, bright blue, 6mm diam, 7mm long, unique mark is same: [M] CE 85°C
  (Note: it's NOT c1. The c55 mark is on the PCA, behind the cap )

("[M]" is M in a box, the Panasonic/Matsushita logo, then "CE" is normally the series code, then 85°C is the temp rating.)

But there has never been a CE series.

As for the part numbers, ECEA0JPK221 and ECEA0JPK470, everything checks out except the series, which says "PK" but that has never existed either, according to Panasonic.

It would be great if you can add insight to this puzzle, either with:

• confirmation that you've got (N) devices that match, and/or
• yours have original caps that are different (what are they) and/or
• yours have replacement upgrade caps that work great (what are they)

Such fun!

[lordsmurf]

You make a lot of interesting posts on AG-1980 in recent months. I rarely participate, nothing to add, but I read. Indeed, interesting.

I dare not open my AG-1980, having just gotten them fixed by deter, and not wanting to tempt fate. I need to use these now, not screwed around with them. However, I have some failed units that I can look at eventually.

I'm tempted to just list cheap for repair/parts in the marketplace, wash my hands of it, move on, give up, somebody else can take a shot.

[yyonline]

Same markings and colors in my VCR.

So C558 tested good on mine. It's not a low-ESR cap, based on my measurements.

C555 tested at 158uF, much lower than the 220uF it's supposed to be. I'm going to replace that one. I'm going to go with Panasonic KA for both and hope for the best, based on the fact that they don't appear to be low ESR.

I see a lot of metallic blue capacitors in old Toyota radios made by Panasonic. I wonder if these are audio-grade caps? Many manufacturers use bright metallic colors for audio caps. Do you have a schematic of the head amp board?

[yyonline]

I found this photo on Farnell: https://www.newark.com/productimages/large/en_US/4767318.jpg

They're blue, and don't have a series marking beyond "CE". They are a product image for AK series, which is an audio cap. AK series appears to be discontinued, but Farnell has some stock left. I ordered a few and I'll see what they look like when they get here.

Many older Panasonic caps have the series marked after CE. For instance, I have some NHG here marked "CE NHG". So it almost seems like the mystery blue caps on the VCR have no series marking at all.

I found a schematic for the head amp. C555 and C558 the audio head amp circuit, but on the power side rather than the signal side. Therefore, I'm not sure why they'd use an audio cap here, if the originals even are audio caps. Then again, I just repair things as a hobby, I'm not an engineer by any means.

[hodgey]

The Audio-grade caps are normally for signal coupling audio yeah. As you state c55 and c58 are there for power conditioning from the looks of the schematic, so while I could be wrong, I doubt they're anything special. If it's a custom series it's likely just some size/voltage/capacitance combination that wasn't normally made so they could make them fit under the shielding.

Just for a comparison since I had one lying around, the caps in the head amp board for the PAL AG7350 SVHS deck are all KA series.

I've seen some caps that seem to be custom series in panasonic vcr power supplies too, with X as series or as prefix to the normal series code. Some of the ELNA caps in the dvd-recorders and 2000s panasonic vcrs also seem to be from a series I can find no reference too (though presumably they are low ESR type due to their role.) So, I guess it's not unusual that they used some caps that weren't normally available for sale directly.

Quote:

Originally Posted by yyonline

C555 tested at 158uF, much lower than the 220uF it's supposed to be. I'm going to replace that one. I'm going to go with Panasonic KA for both and hope for the best, based on the fact that they don't appear to be low ESR.

Interesting, I experienced the same with the 220uF cap on the head amp board in the NV-HS1000 which is a PAL SVHS VCR form around the same time (though that one was ELNA branded) and for that matter with low profile 220uF capacitors in other vcrs so maybe these larger low profile caps from the time were a bit hard to make last.

EDIT:
The datasheet for the Hi-fi head amp chip that the unknown caps are on the power line too seems to be available too, it doesn't mention anything special about the power lines:
https://pdf1.alldatasheet.com/datash.../BA7745FS.html