computer motherboard capacitor repair

[luke9511]

Probably not, if it's electrolyte high humidity may make it conductive enough to disturb the system.

ah ok, any ideas on how to remove it or should i just keep trying with Isopropyl alcohol?

 

[mneary]

I would try clean (distilled if available) water. Dry it thoroughly.

 

[Nigel Goodwin]

ah ok, any ideas on how to remove it or should i just keep trying with Isopropyl alcohol?

Yes, and a small tooth brush or similar to scrub the board.

If it's really hard you can scrape at it with a screwdriver, but if it's really hard it won't cause any problems anyway.

 

[eggplant_casserole]

Hi there,

I worked in IT for several years, so can confirm that a cap job can sometimes (but not always) cure all.

As for the residue, you could try a foaming cleaner - available from most electronics stores. If you use IPA, be careful where you get it. On older chips, there were soft pads - these disintegrate when in contact with IPA! Any similar foam parts would probably do the same.

Off the top of my head, here are some distributors in the US:

Farnell / Electronic Component Distributors / Suppliers / Electronics, Electrical Parts, Electrical Components and Wholesale Electronics.
**broken link removed**
Mouser Electronics - Electronic Component Distributor
Digi-Key Corporation - USA Home Page

Most of these should be able to help. Digikey and MCM will sell to customers who aren't business, not sure about the others. Digikey should send you out a free catalogue if you ask (may be a form on-site). I think MCM still do, too.

Usually their catalogues will state dimensions. Ours do in the UK.

As for measuring:

Some printable paper rulers

Good luck!

 

[be80be]

you can scrape at it with a screwdriver

Work good just keep the kids
away mine cost me a new board with one. I had waited two weeks to get it to fix a computer put the new one in didn't work checked the CPU and there it was. They cut the track by it. Any way how many of them cap do you want and size I can send them to you for not more then stamp. if you want them.

 

[tariq7868]

Better go through ur or other pal nerd's junk and look for any type of damaged motherboard and comb out the capacitor u need...a large percent of motherboards do have these types of capacitor.. i did the same with a Pentium 3 motherboard and it just did solve the problem..

 

[luke9511]

i just checked like 2 other bad motherboards i have 1 was struck by lightning and no longer works and the other i just noticed has bulging caps but it has something else on the board that makes a burning smell when plugged in so its trash and neither has the right caps

EDIT: this looks like what i need **broken link removed**

 

[Sceadwian]

Oh canned air... Small cans of inert compressed air work great for blowing the solvent around under and off the board.

 

[luke9511]

thanks for all the suggestions i will try some of them once i get the chance thanks alot!!!

 

[luke9511]

is there any capacitors that i could use to replace 4700uf caps?

 

[Nigel Goodwin]

is there any capacitors that i could use to replace 4700uf caps?

Yes, 4700uF - it's a standard value - ensure you buy the correct voltage ones (higher voltage is fine, but not lower). Also it's important that you buy 105 degree ones, 85 degree ones are pretty useless these days.

 

[Hero999]

Low ESR is also recommended.

Also, don't worry about increasing the value slightly, if you have 6800µF capacitors then there's nothing wrong with using them instead.

 

[Thunderchild]

yea: ones of the same value and type only!

 

[unclejed613]

a lot of caps just fail for no better reason than a very bad electrolyte formulation. it's also a very common problem with flat panel TV,s and home audio equipment. once the ESR starts to rise just a tiny bit, it generates heat, which dries out the electrolyte faster, which increases the ESR more, etc..... it's thermal runaway in slow motion.

 

[luke9511]

hey everyone i hope your all doing well, i need a little help with your knowledge, im fixing an old arcade monitor by recapping it etc and im needing to replace 2 diodes resistors or whatever they are with 2.2ohm 2 watt of the same thing, but im not sure which is which, im including a picture hoping you can help, thanks for looking

first picture is what im replacing and the 2nd is what i think im replacing with

 

[Thunderchild]

pictures are not that clear but it looks like a 2.2 ohm resistor

 

[luke9511]

pictures are not that clear but it looks like a 2.2 ohm resistor

sorry for it not being very clear it was the best i could do, is there any color markings i should look at to be sure the ones in the second are as follows, by itself is gold,gold,white,orange and the 2 that are together are brown,green,black,gold

 

[Thunderchild]

make sure the colours bands are exactly the same, make sure the replacement is at least as physically big

 

[luke9511]

make sure the colours bands are exactly the same, make sure the replacement is at least as physically big

the ones pictured in the 2nd pic are not the same as the one in the first, however i did get a kit with the monitor when i got it that has 2 of the same ones in the first pc though a little smaller and blue instead of grey but the color bands are the same and thanks soo much for your help

 

[unclejed613]

there are some flameproof 2 watt resistors that are smaller than the standard 2 watt size. if those came with the repair kit, they're probably ok. i've seen 2 watt resistors the size of a half watt resistor, the difference in heat dissipation being the body material and special coatings that vastly improve the dissipation over standard resistor types. they are very expensive compared to standard resistors.