Recapping

mchambin

Member
2011-03-13 8:21 pm
Which supplier and brand do you recommend ?
I need electrolytics of various values and sizes.

This is for a board in a LCD screen; Over 30 caps, 6 have a bulged top. Not the power supply board ( PSU makes 12V and 20v ), the main board has bulged caps, I presume there are several DC DC converters on this main board.
Screen is: Belinea 10 20 30W.
 
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The big four are Panasonic, Nichicon, Rubicon, Vishay. Less stringent service life end specs are from United chemicon, Cornell Dublier.
I like to buy service life >3000 hours so I don't have to do the job 4 times in 40 years as I did buying TV parts store caps. Digikey & Farnell will show the the service life in the selector table if you ask for it. Mouser makes you read each datasheet. If you buy old * discount caps from farnell, be sure to charge them up with a DC supply series a resistor before use. They are past "shelf life" and need reforming. Check to see how fast voltage sags, sometimes they need reforming twice. I use 12 v supply & a 47 k resistor, even on 450 v caps.
Europeans recommend distributors RS & Reichelt; they don't operate here so no opinion. Whatever distributor, make sure they have a warehouse in your customs zone. It took 4 weeks to get stock through customs from one farnell warehouse in the UK to the one in US that serves me. Make sure to tick the "hold until order complete" box or you'll pay for two UPS boxes.
Good luck on repair. I had a Dell LCD display that would work for 10 minutes before quitting, so I replaced the e-caps. Now it doesn't work at all.
OTOH I've re-e-capped switcher supplies in Allen organ and Peavey audio amps, and they worked. Having a schematic for the amps helped. The Dell was an emergency video replacement for a Samsung 2017 LCD TV that refused to turn on after 23 months. Luckily I found a used input board for the Samsung on e-bay, that worked, except for not turning off. A power strip can deal with that problem.
 
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diyiggy

Member
2019-01-16 12:22 am
If you're talking about lytics, go for long life, high temperature caps, Panasonic FR 105C range or Rubycon long life 125C are good, Vishay, etc, all the usual brands. They have polymers as well. Either Farnell and Mouser work fine in CE. Of course take care about caps needed for smps power supplies which needs to be very low impedance
Automotive rated parts are also less fragile. Sometimes you have also to check some very bad low grades ceramic on such boards...
 

diyiggy

Member
2019-01-16 12:22 am
Yes I know, I didn't say u had to check the ceramic caps with your eyes. With X7R or X8R you should not have problems while with the lower grade and how they are solicited you may have to !


If you hve old ceramc discs (I doubt there are in such gears however) I will desolder one to check the capacitance... if sms...well it's up to you. Sure just swap the lytics...
 

mchambin

Member
2011-03-13 8:21 pm
I opened another monitor I want to repair.
This one has clearly one bulged cracked top electrolytic capacitor.
A 470uF 16V.
Trouble is, it is a SMD cap.
I know with trough holes, but with SMD it will be a first time.
Please teach me.
I see the cap has a plastic base and there are two opposite solder joints at the side of the base.