I can't seem to find these capacitors?

[M.Joshi]

Hello,

I am looking for these capacitors which are leaded and measure approx. 7mm height x 8.5mm diameter.



What type of capacitor should I be searching for? They look different to standard electrolytic capacitors.

Thanks.

 

[Pommie]

My guess would be aluminium electrolytic capacitors. I'm also guessing that the black mark indicates the negative lead - does the arrow on the PCB align with the black sides? Only 1 arrowhead is visible.

Also, that looks like a very old board, any idea what year it was manufactured?

Mike.

 

[augustinetez]

They look like Polymer Electrolytic Caps - made by Panasonic, Nichicon and some others.

RS still sell them and I should think other major component suppliers will have them too.

 

[M.Joshi]

They look like Polymer Electrolytic Caps - made by Panasonic, Nichicon and some others.

RS still sell them and I should think other major component suppliers will have them too.

Thanks, I can't seem to find the same profile. Is there anything special about polymer ones? Is it lower ESR and size?

 

[rjenkinsgb]

We've used similar style ones in the past, but I cannot figure out where they came from! I'd guess Farnells, though they do not seem to do that wide, low profile style any more.



They may well have been discontinued by the manufacturers in favour of surface mount ones.

If the exact size / proportions are not important, then there are a few types available:

https://uk.farnell.com/w/c/passive-components/capacitors/polymer-capacitors/aluminium-polymer-capacitors?capacitance=220uf&voltage-dc-=25v&ae-capacitor-case=radial-leaded

 

[Nigel Goodwin]

Thanks, I can't seem to find the same profile. Is there anything special about polymer ones? Is it lower ESR and size?

I would suggest normal electrolytics would be perfectly fine, are you sure the existing ones are faulty?.

 

[M.Joshi]

I would suggest normal electrolytics would be perfectly fine, are you sure the existing ones are faulty?.

Going to desolder them and check. Can't measure them properly in-circuit. It's for a backlight inverter board where the fuse has blown. Lots of darkening on the PCB.

 

[Nigel Goodwin]

Going to desolder them and check. Can't measure them properly in-circuit. It's for a backlight inverter board where the fuse has blown. Lots of darkening on the PCB.

I would say it's VERY, VERY unlikely to be those capacitors. Have you replaced the fuse?, and did it blow again? - inverter fuse failure for no reason is common.

If the screen LED or CCFL?.

 

[M.Joshi]

It's a CCFL on an old Sony Bravia TV. Haven't replaced the fuse yet. Why is fuse failure common?

 

[Nigel Goodwin]

It's a CCFL on an old Sony Bravia TV. Haven't replaced the fuse yet. Why is fuse failure common?

I've always presumed it's simply aging/failure of the fuse, no cause for it.

Replace the fuse, it will be perfectly fine - as a Sony Dealer Engineer I replaced countless inverter fuses (SM ones) in numerous Sony sets - and in fact I have one of them in my bedroom. Incidentally the fuse is on the inverter board, which is part of the LCD panel assembly, and which isn't a Sony part at all.

 

[augustinetez]

Thanks, I can't seem to find the same profile. Is there anything special about polymer ones? Is it lower ESR and size?

https://uk.rs-online.com/web/c/pass...lymer+capacitor&applied-dimensions=4294817747

As per others, not likely to be the caps blowing a fuse.

 

[M.Joshi]

When removed from the boards, almost all 20 of the capacitors measured out of spec between no reading to typically 80-140µF.

Attached is a photo showing the burnt PCB leaded fuse. Looking at photos of other inverter boards for sale, it seems to be a F10A. Is anyone able to confirm from the schematics?

 

[rjenkinsgb]

There is a spare board in clean looking condition on ebay at present, for a very low price:

INVERTER FOR KDL-20S4020 KDL-20S2030 KDL-20S2020 TV PCB2684 A06-126313 CSN306-00 | eBay

PCB2684 A06-126313. INVERTER BOARD. This item is compatible in above specified model.

www.ebay.co.uk

 

[Nigel Goodwin]

Did you ever try just replacing the fuse?.

 

[M.Joshi]

Is it definitely an F10A?

 

[Nigel Goodwin]

Is it definitely an F10A?

As it's not a Sony board there's no schematic for it, and no information at all (it's supplied by the LCD panel manufacturer as part of the LCD).

It's been so long now I can't remember what I used to fit - but stick your meter on the 10A range across the fuse, and measure what current it takes (that's what I did originally).

 

[Nigel Goodwin]

I wouldn't guarantee it, but I seem to recall fitting a 4A circuit protector, which was the largest size we used to stock.