Identifying capacitor type (Laserdisc PSU)

[LeBeauLuc]

Hi,

I am trying to figure out what type of capacitors those could be, the picture attached is coming from a laserdisc power supply from the late 90's. I have accessed to the service manual and it is lacking the info for the 20 capacitors and doesn't specify the type either. Looking at the value, those seems to match ceramic type, are those ceramic?

[eccerr0r]

Re: Identifying capacitor type (Laserdisc PSU)

caps that look like that are usually polystyrene. If there are that many of them, they probably chose cheapest and other plastic caps will work just fine...


...though they usually don't fail...

[LeBeauLuc]

Re: Identifying capacitor type (Laserdisc PSU)

caps that look like that are usually polystyrene. If there are that many of them, they probably chose cheapest and other plastic caps will work just fine...


...though they usually don't fail...

Thank you very much for the info, eccerr0r.

Also, I wanted to know if it is normal that the one I circled red to look that dark compare to the one circled green, I am thinking that it might be toasted.

[redwire]

Re: Identifying capacitor type (Laserdisc PSU)

To me they look like polyester mylar film capacitors similar to Nichicon QXY. I would replace with Panasonic ECQB (although obsolete) or anything with the same lead spacing and ratings. Polystyrene is always tubular shaped and they don't look like that to me.

They should be yellow coloured, so the darker brown/red parts have been affected (cooked) by the nearby power resistors' heat. I would replace them.

[PeteS in CA]

Re: Identifying capacitor type (Laserdisc PSU)

The brownish cap is between a heatsink and a power transformer, both sources of heat, and possibly impeding airflow or convection, and as redwire noted, there are two 1 watt resistors near the cap.

FWIW, the first picture has what I think is a Shindengen logo in the PCB silkscreen. Power supplies tend to have mostly polyester film capacitors, with some polypropylene parts in important places.

[LeBeauLuc]

Re: Identifying capacitor type (Laserdisc PSU)

Thanks all for that valuable info, looking on the interwebs, they do appear to be polyester film capacitors, knowing that I will be able to replace the burned ones.