Need a replacement capacitor

[Oakey]

One of my monitors blew up this morning, or more specifically one of it's capacitors did. Despite googling the markings on it there seems to be a variety of similar but slightly different matches. Anyone able to find this exact cap:



On the side it says PW(M)105c(C)0521

[Gary29]

https://www.tme.eu/gb/details/pf2w121mnn1845/105c-...

[Oakey]

Thanks Gary, will give that a go

[Gary29]

Well it matches the electrical spec, I'd just compare the physical dimensions to make sure they are the same before ordering one.

[peterperkins]

It looks like it may be part of the Switch Mode Power Supply.
It may have been taken out by another component failure nearby.

When an SMPS dies it can be a royal PITA to fix..
Replacing the cap certainly won't guarantee a fix.

Has it blown any onboard fuses as well?

[Oakey]

Everything else looks fine, and the cap is like a couple of quid so it seems worth having a go at fixing it before binning it. I should point out it's a Dell monitor that's almost 15 years old and a quick Google suggests this isn't an uncommon failure.

Edit: on closer inspection, just noticed this has gone too

Edited by Oakey on Tuesday 19th March 14:36

[curlyks2]

Oakey said:

Everything else looks fine, and the cap is like a couple of quid so it seems worth having a go at fixing it before binning it. I should point out it's a Dell monitor that's almost 15 years old and a quick Google suggests this isn't an uncommon failure.

Edit: on closer inspection, just noticed this has gone too

That looks like a 0.22ohm resistor, need to know the power rating really: https://www.mouser.co.uk/Passive-Components/Resist...

Choices on the capacitor originally asked about too: https://www.mouser.co.uk/Passive-Components/Capaci...

[anonymous-user]

Work with caution or you may have an unpleasant surprise, check and double check the big capacitors before working on them.

[Oakey]

From this thread; https://www.badcaps.net/forum/showthread.php?t=148...

R670 is 0.22 Ohm, 1 Watt.

[ATG]

The 120uF (microfarad) is the capacitor's capacitance. The 450V is the max voltage it is supposed to stand. So you should be OK to replace it with any 120uF electrolytic capacitor rated to at least 450V. And make sure you connect it the right way round; electrolytic capacitors are not reversible.

I'm sure it'll be easy enough to find a resistor colour code table on the interweb. There'll be 4 coloured bands on the resistor. 3 of them translate into a digits to represent a number of the form X.Y × 10^Z ... e.g. if they were 1, 2 and 3, then the resistance would be 1200 Ohms. The fourth band indicates the "tolerance", the margin of error as a percentage in the indicated resustance. And the size of the resistor tells you its power rating. Off the top of my head I can't remember what your one is; probably 1/2W. Your replacement resistor should have exactly the same resistance markings as the original, the tolerance should be the same or better, and the rated power dissipation should be the same or better. No need for better; point is it doesn't matter if they are, so if you have "better" lying around or you can scavenge them from something else, they'll be fine.

Edited to say: poster above says 1W for the resistor. Very likely right. Hard to judge size from the photo

Edited by ATG on Tuesday 19th March 16:00

Edited by ATG on Tuesday 19th March 16:00

[Oakey]

I've found a replacement power board on Ebay for £10 from China so I may as well just buy that. As much as I thought this would be an easy fix, when you take into account sourcing all the components, trying to identify if anything else has gone wrong but may not be visibly damaged, the time desoldering and soldering everything to the board, etc it works out easier to just spend £10 on a replacement board. Can't compete with that!

[curlyks2]

Makes complete sense. Had similar with a power supply in some audio kit last year but a replacement was about £110, so tried the replacement capacitor route first which worked so saved £108. If a full replacement had been available for £10, I'd have just bought that.

[Oakey]

Wasn't a Kef sub was it?

[Whoozit]

I had something similar on a Samsung 22 inch TV. New power board, £15 IIRC, and away we went.

[curlyks2]

Oakey said:

Wasn't a Kef sub was it?

No, it was a mixer. The caps that came out were standard/budget 1000 hour lifetime items; I spent a few pennies more (literally) to replace them with 10000 hour longlife ones. You have reminded me though... I do have a sub (not a Kef) in need of some PSU tlc.