Can't find exact matching caps for replacements, what should I get to prevent video issues?

[SluggerB]

I have an old Tivo. The Power Supplies are known to have caps that fail. Here are the caps that come with the original power supply:



I could not find replacement caps with the exact same specs. I followed an online guide and recapped the power supply with caps with these specs



The power supply now works, however the HDMI video is giving me eye strain. I don't know how a capacitor on a Power supply could impact an HDMI video signal, but it does, the Tivo interface has a flicker now and the color/brightness is off. So I want to get some new caps that as as close to the original specs as possible, but exact replacement don't seem to be available to order anywhere. I can match the capacitance and voltage but the ripple and impedence are more difficult, sometime I can match the ripple, but often I can only get kinda close, sometimes I can't even get close with what is available. The replacement guide says "the ripple current must be equal to or higher than the original parts".

Ripple seems to be the main thing I can differentiate on here, so if I can't find an exact match how far is it OK to deviate? Is a lot higher better than a little lower? I'm not sure what the interplay is between ripple, impedence, and the HDMI video signal.

[stj]

in a switching psu you want low esr.
dont bother matching the originals - it was built to a price, go a bit lower on the esr - the increase in ripple current handling is a bonus.
in europe the best low esr caps for the money are panasonic FR, but in the u.s. it may be nichicon

[SluggerB]

in a switching psu you want low esr.
dont bother matching the originals - it was built to a price, go a bit lower on the esr - the increase in ripple current handling is a bonus.
in europe the best low esr caps for the money are panasonic FR, but in the u.s. it may be nichicon

OK I will see if I can find aset of 8 with lower ESR than the ones I listed, and for Ripple I should look for higher?

[stj]

yes, lower esr and higher ripple is good.

[SluggerB]

yes, lower esr and higher ripple is good.

OK I went through my list one by one and saw what I could find, replacement wise, focusing on low ESR and High Ripple. Here is what I found:

• 470UF, 200V - I already have the lowest ESR and Highest Ripple cap listed
• 47UF, 50V - I have 300mA Ripple/430 mOhm ESR Caps, I found 405mA Ripple/140 mOhm ESR caps, I assume these would be better (lower ESR & higher Ripple)
• 10UF, 25V - I have 160mA Ripple/1.5 Ohm ESR Caps, I found 230 mA Ripple/520 mOhm ESR caps, I assume these would be better (lower ESR & higher Ripple)
• 2.2UF, 50V - I have 55 mA Ripple/4.5 Ohm ESR Caps, I found .45 mA/1.8 Ohm Caps, would these be better? Note the lower ESR but lower Ripple
• 1000UF, 10V - I have 1.56A Ripple/30 mOhm ESR Caps, I found 1.79 Ripple/26 mOhm ESR caps, I assume these would be better (lower ESR & higher Ripple)
• 470UF, 16V - I have 1.24A Ripple/41 mOhms ESR Caps, I found 1.29A Ripple/38 mOhm ESR caps, I assume these would be better (lower ESR & higher Ripple)
• 2200UF, 10V - I already have the lowest ESR and Highest Ripple cap listed
• 1000UF, 16V - I already have the lowest ESR and Highest Ripple cap listed

[SluggerB]

Also which of those values (ESR or Ripple) would have an impact in the HDMI video signal?

[stj]

you usually dont have to replace the mains smoothing cap - the 200v one

[SluggerB]

you usually dont have to replace the mains smoothing cap - the 200v one

I've had one of them go bad on another power supply, but I will leave the original on this power supply.

Any thoughts on which of those values (ESR or Ripple) would have an impact in the HDMI video signal?

[stj]

any good caps should not cause noise in the system.

[SluggerB]

any good caps should not cause noise in the system.

Thanks. How about this replacement:

• 2.2UF, 50V - I have 55 mA Ripple/4.5 Ohm ESR Caps, I found .45 mA/1.8 Ohm Caps, would these be better? Note the lower ESR but lower Ripple

I'm assuming the other replacements are OK?

[stj]

thats not smoothing the output - so isnt important

[SluggerB]

thats not smoothing the output - so isnt important

OK thanks, I will order those up! I really appreciate the help!