Can I replace damaged capacitors in my power supply with a 1000uf cap?

[slee95]

The monitor/ tv will power on for around 30s and i can see all the icons on the tv but then will shut off I'm thinking its the power supply so i took a look at it and 3 of the capacitors look bad i have no clue where to get capacitors in the Harrisburg Mechanicsburg are. I don't want to buy online i want to buy from a store though. Can i use a 1000uf cap the 3 caps that look bad are 820uf 25v.

 

[yungman]

If you don't want to buy online and you can't find one in your area, you got a problem!

 

[slee95]

but would a 1000uf substitute for a 820uf cap?

 

[yungman]

but would a 1000uf substitute for a 820uf cap?

If it is a filter cap, yes.

 

[Studiot]

820μF is a funny value to put in a psu filter rather than 1000 are you sure it is a filter cap as yungman said?

 

[jim hardy]

there's lots of sites where people discuss their repairs

my son fixed a 50 inch samsung with help from folks here
three Radio Shack caps got his trashpile-rescued tv going for around seven bucks

http://forums.anandtech.com/forumdisplay.php?f=38

try a google search on your model and symptom.

 

[slee95]

I got the capacitor. Noticed a tv store on my way to a doctors appoint and got it for $6. filter cap? I'm still learning about electronics at votech the cap is a dc capacitor like this pic http://www.google.com/imgres?num=10...w=131&start=0&ndsp=18&ved=1t:429,r:1,s:0,i:75. Ok now to install it will i have to be grounded while handling the power supply? If so i do not own a grounding reistband what else could i use to ground my self?

 

[vk6kro]

If you had bad capacitors, you would be getting bad smells and possibly crackling noises.


If you are using Windows XP, there is a "power options" icon in Control Panel which could turn the monitor off in as little as 1 minute.
Worth checking this by borrowing a friend's monitor to check it. If your friend's monitor turns off too, then it could be a computer setting.

If you power up the monitor and computer separately, then turn the computer off then on but leave the monitor turned on, do you get the same effect?
The monitor should stay off if it is causing the problem, but it should give a short period of normal picture if it is the computer doing it.

 

[slee95]

If you had bad capacitors, you would be getting bad smells and possibly crackling noises.


If you are using Windows XP, there is a "power options" icon in Control Panel which could turn the monitor off in as little as 1 minute.
Worth checking this by borrowing a friend's monitor to check it. If your friend's monitor turns off too, then it could be a computer setting.

If you power up the monitor and computer separately, then turn the computer off then on but leave the monitor turned on, do you get the same effect?
The monitor should stay off if it is causing the problem, but it should give a short period of normal picture if it is the computer doing it.

It does show all the computer icons for a very brief time then shuts off and 3 of the caps look really blotted on the power supply so i will replace them but did not know if its static sensitive. The monitor/tv it has the port for either or is a samsung with speakers on the side and is at work so i don't know the model numb. but i will know tomorrow.

 

[slee95]

Oh the computer tower i tested it on was a e-machines with xp. I like the monitor and they were going to throw it away so I'm attempting to repair it. When i pull the power cord off and back on it will show the computer icons but only briefly the monitor works but only stay on for 30s or so.

 

[slee95]

blotted is a typo i meant to say enlarged like this http://www.google.com/imgres?um=1&h...w=170&start=0&ndsp=16&ved=1t:429,r:7,s:0,i:97

 

[vk6kro]

That sounds better, but don't waste too much money on it.

Nobody wants CRT monitors any more and you can pick them up cheaply ($15) or free.

No, power supplies are not usually static sensitive, but beware of capacitors that can hold charges long after the power is turned off. They can zap unwary fingers.

 

[slee95]

thanks vk6kro the caps only costed be $6 while i have the back off of it what other things should i look at before powering it up again?

 

[vk6kro]

You realize that this is a bit of a gamble, so if you are sure you have the polarity of the capacitors right and you haven't accidentally pulled any plugs out of their sockets, just turn it on and see what happens.

If it behaves the same as it did before, I would ditch it.

Collect your capacitors out of it and any power transistors, Schottky diodes, ICs, ferrite toroids or heatsinks for your junk box and get rid of what is left.

 

[slee95]

Than kvk6kro very much :).

 

[NascentOxygen]

It does show all the computer icons for a very brief time then shuts off and 3 of the caps look really blotted on the power supply so i will replace them

I'm intrigued; what does a capacitor look like to appear "blotted"? http://img845.imageshack.us/img845/1143/confusedsmiley010.gif

My feeling is that if 3 capacitors can be seen to have burst, there are probably 10 times as many hidden away on other boards, or on the underside, that are in an equally poor state.

 

[slee95]

The monitor lives again and is working good :) NascentOxygen yes the old ones were partially exploded and no the caps where only on one side. :)

 

[NascentOxygen]

The monitor lives again and is working good :)

I hope your rescue enjoys a long and productive second life.

 

[slee95]

Thank you NascentOxygen very much :).