Sony SAT Receiver

[Gianni]

Today I repaired a SAT Receiver, it was easy because I found immediately the culprit: the VDD cap, on VIPer50S supply voltage, was completely out of spec, it was 1.22uF 565ohm instead of 47uF.
I think it is normal that after some years it failed because Rubycon YK are not low ESR for high frequencies.
I replaced it with 47uF 25V YXF.

Here some pics.

Ciao
Gianni

[japlytic]

Re: Sony SAT Receiver

This capacitor would be most likely to be used for filtering the low voltage supply on the primary for the switchmode controller IC.
I prefer to use low-ESR units on all parts of the power supply section, except for the 400/450V unit, all of which are 105C units.

[Krankshaft]

Re: Sony SAT Receiver

I had a ton of Rubycon YK fail on my Orion built (Toshiba branded) 27" TV. They don't like heat at all they failed in under 5 years. First they screwed the functionality of the vertical circuits (horizontal lines in picture) then the microcontroller circuits (TV turning on by itself and changing channels randomly).

Replaced them with Pana FCs. The ones above the ICs went high ESR there was a slight board darkening so they were kept toasty by the SMT ICs underneath. More the reason why 105Cs should have been used.

Personally I think there is no place for 85C caps in any modern electronics but the factories will get an extra few pennies wherever they can.

What's worse they didn't bulge either if I didn't have my ESR meter to sniff them out I'd still probably be scratching my head.

[Krankshaft]

Re: Sony SAT Receiver

It may be that the temps in these electronics are too high for these 85C caps or this is a lemon series from Rubycon.