Replacing Nichicon PJ and PF in a PSU

[Y. Signal]

Hello, I want to recap the PSU in the photo so I'm looking for adequate replacements and I have some questions. This is the list of electrolitic capacitors (rated ripple current in mArms at 85ºC in parenthesis):

• 1uF 50V Nichicon VR
• 2.2uF 50V Nichicon VR
• 180uF 16V Nichicon PF
• 560uF 16V Nichicon PJ
• 39uF 400V Nichicon VZ

- Is Rubycon BXW 39 uF 400V a good substitute for the VZ?

- For VR replacement, rated ripple current (mArms at 85ºC) is lower in Rubycon PX, and higher in Rubycon YXF. Are the PX adequate because they are used as GP, or should I choose other caps like the YXF in spite of being low ESR with higher ripple current?

- For PF and PJ replacement, since the capacitance values are 180uF and 560uF I've considered to use Panasonic FC, they have a slightly better ripple current (555 instead of 405 and 1050 instead of 950) which is good, but impedance is considerably lower (0.117 vs 0.31 and 0.06 vs 0.12). Are they ok for this application?

Thank you in advance.

[momaka]

Re: Replacing Nichicon PJ and PF in a PSU

PF is just the old obsolete series that was later replaced with PJ. They are equivalent in specs, though. See this:


As far as I know, PJ series are not problematic (unlike PR and possibly PL + PF series - the equivalent of PM and PJ series), so I wouldn't replace them unless absolutely needed... and if needed, I think you can still find Nichicon PJ for sale.

This adapters appears to use flyback topology, however, so using caps with lower ESR should be okay. As such, Panasonic FC will likely work fine. Another equivalent of those are Nichicon PW and United Chemicon KYB (both of these you will likely find cheaper). United Chemicon LXZ is probably the second closest to Nichicon PJ, but still with considerably lower ESR. Rubycon YXJ is close in specs too, but it doesn't have 180 uF and 560 uF @ 16V. Otherwise, they are excellent for PSU use.

On that note, regarding the Nichicon VR replacements... yes Rubycon YXJ is fine, since this is a swtiching power supply. Same goes for Nichicon PW, United Chemicon LXZ, and Panasonic FC, as all of these are rather similar in specs. For the small caps, I regularly use one of these brands/series (and sometimes even Nichicon PM/PS, though I've been finding lately that PM/PS may not be that trustworthy).

As for the Ruby BWX replacing the Nichi VZ for the 39 uF @ 400V cap... probably okay, as this is the bulk input filter cap. If space (and budget) allows, I always try to go for bigger input caps.

[PeteS in CA]

Re: Replacing Nichicon PJ and PF in a PSU

Nichicon PJ series and Chemicon LXV series are equivalents. PW, LXZ, and FC are equivalents. So if the original PJ and PF need to be replaced. PJ and LXV would be the closest equivalents, and PW, LXY, LXZ, and FC are lower impedance, but probably close enough to be fine.

[Y. Signal]

Re: Replacing Nichicon PJ and PF in a PSU

Thank you for the detailed replies, it's much appreciated. I'm still learning the basics and this helps me a lot to make the correct decisions.

I've just recapped another PSU, and the only capacitor out of spec (I simply measure capacitance) was a Nichicon PR 10uF 25V. The Nichicon PL and Panasonics (GE, NHG and FAU) were pretty close to spec in capacitance.

[PeteS in CA]

Re: Replacing Nichicon PJ and PF in a PSU

The PR series was discontinued in the mid 2000s because it was not RoHS compliant. The same is true of the PL series. But:

* The PL series was replaced with the RoHS-compliant PM series;

* The PR series was replaced with the RoHS-compliant PS series.

[momaka]

Re: Replacing Nichicon PJ and PF in a PSU

Nichicon PR has problems with caps leaking electrolyte from the bottom, so always change all PR series on sight. PL, I think is fairly stable, though I haven't seen that many of them to conclude anything.