Panasonic switching power supply daughter board has two 27uf @ 50 volt capacitors which I do not keep in stock

[sam_sam_sam]

I don't see a main PWM control IC in there, but the two 27uF caps might be for the driver stage of a 1/2 bridge, they are to keep imbalance or maybe average current reasonable. They see action when the PSU is heavily loaded.
Never seen a Marcon primary cap before 180uF 400V.

Actually I did have a few 27uf @ 50 volts but they were in a container that is odd values or low voltage capacitors that I mainly use for 5 volt switching power supplies I did not even think about looking in this container because I was looking for some 3300uf @ 35 volt I have some but they are not brand name ones for this switching power supply but I am not going to change them because of the quality of these boards and that I had to do a repair job in four places

[CapLeaker]

To date I have not figured out what the substance was. Almost like dried up FluidFilm. Weird. I also can't figure out why this “coating” was just in the power supply, And it was sucked in from the front. The 2 radios inside were clean as a whistle. If someone would have sprayed it from the front, it would have been all over the place inside.
so this would really limit things.
I did figure out the playing dead problem. It was the bigger ribbon cable that is between the TX radio and the front LED board. The ribbon cable chaffed down to the Ethernet cable that goes between the board on the front and a temperature control board on the back.
Sorry sam_sam_sam I totally hijacked your thread.

[sam_sam_sam]

Sorry sam_sam_sam I totally hijacked your thread.

I would not worry about that because I have been interested in your off topic about my endeavors about my Panasonic switching power supply that the circuit boards are crap and how you are trying to resolve your own issues with your experience with the substance in your switching power supply so it is not completely off topic

[Agent24]

27uf +20% for tolerance is 32.4uf
just saying

Ah, but what if your 33uF capacitor is also +20%....

[stj]

never happens - ever
i suspect caps are graded like leds and the good ones go to specific customers while the average ones go into the supply chain

[Agent24]

never happens - ever
i suspect caps are graded like leds and the good ones go to specific customers while the average ones go into the supply chain

By that reasoning though, the original 27uF caps would never have been +20% either.
So the circuit may well be unstable with something that much higher

[stj]

well lets see the board

[sam_sam_sam]

well lets see the board

In post # 9 I showed one side of the board but I am not going to remove it again because of how poor the soldering joint traces because I plan on reusing it for a project that I want to complete I am going to replace the output capacitors I just have not got to this part of the recapping process of this board yet

If I can take a better picture of this board I will post it

[redwire]

I think today they can manufacture electrolytic capacitors within a few % tolerance. It's not the 1950's anymore for the -20%/+80% number, and its +/-20% nowadays still a 40% wide window.
Many larger caps I've bought are at basically at -18% lol. An old cap is 82uF 450V, the new one measures ~70uF (happened several times) so I end up upsizing and buying 100uF to get 85uF. This is Chemicon and Nichicon. Why would you give the customer more than what the spec is

Smaller caps seem to be closer tolerance to rated value, so a 27uF would be very close to that.
Wild guess this is a half-bridge SMPS and the 27uF is part of the driver circuit, like in PC power supplies.

[sam_sam_sam]

These are the best pictures of the daughter board