Need Advice on a Capacitor

[tillmbil]

I purchased main power capacitors for an JVC RS-5. 6800uf 35v and they arrived from Mouser as a two pin
application. Unfortunately when I un-soldered the ones in the receiver they have three pins. Can you help me with a part number from mouser so I can get the right ones? I ordered the Nichicon PW's in the two pin style.

Thanks

 

[petehall347]

2 pin should work . thats so long as 3rd pin is not connected to anything

 

[knockbill]

Yep,,, the 3rd pin in the old ELNA was probably a ground lug, so if you had wires connected to all 3 pins, check the pics you took before disassembly,, or a schematic to be certain where the 3rd lugs wires go...

 

[gadget73]

Once in a while you'd see two ground and one hot, or sometimes the third pin was just for mechanical support. I have something that was a 2 ground, one hot, and the board was designed in such a way that it used the capacitor as a pass-through for the negative side. It needed a jumper installed to make it all work again with a modern 2 pin cap.

either way, you can use the 2 pin, just add a jumper if needed.

 

[NAD80]

Found the schematic here. http://www.vintageshifi.com/repertoire-pdf/Jvc-9.php. if you need it.

 

[redk9258]

Usually the extra pin will say no connection. It is only for support. If you look at the solder side of the PCB, the pad is usually isolated. You may have trouble putting the leads of the new cap through the PCB because of the pin spacing.

 

[redk9258]

According to the schematic, only 2 connections are made...

 

[gadget73]

you'd have to look at the board to confirm that. The Pioneer I pulled the 3 pin caps out of only shows two electrical connections, but it actually used all 3 in a specific way. Electrically the schematic was accurate but the physical board layout didn't quite jive with it.

 

[tillmbil]

Ok, I will take a picture for you guys to look at. Still confused on the issue.
Thanks

 

[tillmbil]

redk, where did you get the schematic? I could not find it on vintagehifi

 

[tillmbil]

Never mind I found it, thanks for the link.

 

[tillmbil]

Here are some pictures of the PCB board. I have the schematic now but do not see a parts list. Any idea where one might be?
Thanks gain for your help. I am trying to upgrade this as practice before I tackle anything more expensive.

 

[petehall347]

looks like the 3rd pin isnt used for electrical connection

 

[Blue Shadow]

looks like the 3rd pin isnt used for electrical connection

This is seen by the pin being in an area of the board that does not have the trace on it. You can see the traces from component leads and that color is different from the areas that don't have the copper trace on the board anymore, removed when the board was manufacturer.

 

[redk9258]

It that crap all glue? Or is it glue plus cap puke? I have two R-X40's. One looks like that one doesn't. Maybe someone at the factory went crazy with the glue. On any account, it needs cleaned off!

 

[gadget73]

agreed, doesn't look like an electrically connected terminal.

brown stuff looks like glue to me. That stuff can become corrosive though, so either way it needs to be cleaned up.

 

[redk9258]

I started the recap on my R-X40. There was a bunch of the crap on mine too. I scraped most off with a small screwdriver and used alcohol on a QTip to get as much of the rest off that I could.

 

[tillmbil]

I believe it is glue that spread from the heat. I am cleaning that up as you say. Probably excessive heat, since these are low powered receivers. I will go ahead and use the 6800uf 2 pin caps that I bought. I will post some more pictures, and eventually a finished product.

 

[tillmbil]

Here is a couple pictures of the recap so far

 

[tillmbil]

If anybody is looking I have now completed the re-cap as far as I can with my limited skills. It sounds pretty darn good, no distortion up to 12 o'clock on the volume knob on a pair of Minimus 7's. I have taken some picture0s and was hoping someone had an idea how to set bias and DC offset if possible. The current DC offset numbers are
RF -37.4 LF 6.9 RR -40.0 LR 9.1 not too bad but the right side channel's are a bit high. Again any help would be greatly appreciated as I delve into recapping old electronics