How to calculate the total voltage and capacitance of capacitors?

[one_love]

My friend monitor Samsung Syncmaster B2030 screen is showing wavy line and the screen becomes full white after few min. I brought the monitor to my home to check if the monitor is faulty and when I connected to my system it show same problem. I suspect the monitor power supply is the problem.

I want to change the two electrolytic capacitors which have value 1000mf 10volt in parallel. I don't have two 1000mf 10volt capacitor so I want to know if I can connect only one 2200mf 10volt ? Will it work?

 

[andy_in_kenya]

Hi one_love,

are you absolutely positive the two caps are really connected in parallel? Not perhaps only connected to the same rail on the negative side, but then to different ones on the positive? This would actually be the common way to 'wire' them. I'd consider it quite unlikely for a commercially manufactured circuit to use two caps in parallel (which would effectively result in capacitance being the sum of the two single caps) rather than just going for one piece of the wanted capacitance which would in nearly all cases be the cheaper solution. For the board design as well as for material costs...

Please carefully check again whether the negative (marked) pins are joined together without any other components between them (except for wire bridges or zero ohm resistors) AND even the positive (unmarked) ones.

IF they are truly in parallel, then yes, you can just use one piece of 2200 mikrofarads/10V to substitute them. But really only then...

BTW, be VERY CAREFUL when you handle the power supply circuits of that screen. The main filter Cap can under circumstances hold a high charge for quite some time, plus (if it's not an LED model) probably the same board will also carry the high voltage inverter circuitry for the fluorescent background lights. DANGER!
Make sure you ALWAYS disconnect the mains power before you do anything on the circuits. And still be careful. Safety first...

Best
Andy

 

[one_love]

Best answer selected by one_love.

 

[one_love]

I am happy to see that some1 had replied to my question, thanks for taking time to write the answer. I had studied basic and advance electronics in radio and television. I had certificate for it. It was 10years before that I had completed my technical studies. I was giving home services in t.v. repairing for atleast 2-3 years and I had worked with t.v. SMPS also. For 1year I stop doing repairing of t.v. and because of this long break I forgot the series and parallel capacitor how to calculate value?
Thanks you again for replying and for your help.

 

[andy_in_kenya]

You're welcome mate.

We're actually sort of colleagues... My professional training in Germany was electronics, but digital rather than analogue TV/Radio. Had to decide which way to go, two different branches 27 years ago...

Cheers!

 

[one_love]

I am now working with only PC's someday all CRT will be replaced with Flat panel display and the technology is so much fast changing that in future there will be no soldering iron needed. I am thinking what will be the future where common person who don't have electronics knowledge can also change a PCB where there is no need for us.

 

[andy_in_kenya]

Well, let's face it - basically that is even possible TODAY already. If people are willing to bother about finding the part, opening the device in question and even paying the price for the part at the risk that they might still mess it up... At least here in Kenya they still rather prefer to call me for help if anything goes wrong. But well, I'm working mainly with IT hardware. Let's just hope for the best, at least until we will retire... Cheers!