I want to change the capacitors on my LCD monitor power board.

The power board of the LCD is the following:

LCD Power Board

The 3 of them who have the upper part popped are 820uF 25V.

If i remember something of electronics that part is some kind of filter.

Is correct to assume that I can take bigger capacitors keeping the same voltage, this should make the filtering better right? I ask this because by buying them on online shops is not always possible match all the same specs, for example can I replace them with 3 x 1000uF 25V ?

Also, should I check something else before buying them? I remember people talked also about Low ESR or something like that? Someone can explain me what it means and help me pick the right replacement for a case like this?


closed as off-topic by Leon Heller, Matt Young, Null, Daniel Grillo, PeterJ Nov 14 '15 at 23:01

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "Questions on the repair of consumer electronics, appliances, or other devices must involve specific troubleshooting steps and demonstrate a good understanding of the underlying design of the device being repaired. See also: Is asking on how to fix a faulty circuit on topic?" – Leon Heller, Matt Young, Null, Daniel Grillo, PeterJ
If this question can be reworded to fit the rules in the help center, please edit the question.

  • 1
    \$\begingroup\$ Just replace everything with what it says on the case. Unless you know exactly what you're doing, fiddling with the values is not a great idea. \$\endgroup\$ – Daniel Nov 14 '15 at 18:10
  • \$\begingroup\$ @Daniel My only problem is that I'm not very able to find around 820uF capacitors, I found easily 1000uF 25v, and a friend of mine fixed a same situation by changing 820uF 25v with 1000uF 25v and it worked and for long. But obviously I raised the question for the sake of learn. \$\endgroup\$ – user3450548 Nov 14 '15 at 20:36

This is a Samsung LCD, right. I did replace with 3 x 1000uF/25V (Syncmaster 931). If I can remember well they are all in parallel, if so, you can use 2 x 1000uF + 1 x 470uF.

  • \$\begingroup\$ Yeah is a Samsung LCD. I took this pic some time ago, so I should re-open it and look closely but yes, I think they are in parallel indeed. So instead of using 3 x 820uF = 2460uF I could go for 2 x 1000uF + 1 x 470uF = 2470uF that is pretty close, thank you! Also i think that 3000uF (3 x 1000uF) could work good the same, the frequency cut of the filter would be just slightly shifted. \$\endgroup\$ – user3450548 Nov 14 '15 at 19:33
  • \$\begingroup\$ As said I don't remember well, can be that only 2 of them are parallel 1000+690, I did change all with 1000uf and it is working. I have changed all caps except the big one, is rated 450VDC, but it is at the input rectifier, in shop they had 400VDC rated but I didn't know the positon, as I made a quick list of all caps. We have 230VAC so 230*1,41=325V. Anyway don't bother too much, change the caps (I spent 5€ for all) and bring the monitor back to life. \$\endgroup\$ – Marko Buršič Nov 14 '15 at 23:34
  • \$\begingroup\$ I checked the board and, yes, they seems to be in parallel configuration. So probably I will go without too much throubles with 3 x 1000uF instead of the original 3 x 820uF. I will not change all the caps there because it would be too much time consuming and they seems to be in a good / unstressed state. Thanks ;) \$\endgroup\$ – user3450548 Nov 15 '15 at 0:45
  • \$\begingroup\$ I really don't understand why all this frenzy by mods to mark things as offtopic/downvote/close. I read the rules linked, before posting and only the: "The device contains proprietary chips (no documentation)" could be considered into this topic (even if assume is a rule referred to FPGAs, ..). In this case is just a visible capacitor replacement where you don't need such documentation, also I tried to ask the question as more generic / not localized possible. A further user would easily apply the knowledge learned here for fix another monitor / power board, just maybe with different uF specs. \$\endgroup\$ – user3450548 Nov 15 '15 at 0:59
  • \$\begingroup\$ It's a very poorly framed question, that is more or less unanswerable. By sheer luck Marko recognizes this (unidentified in the question) circuit board and has done this same mod. BY SHEER LUCK. Otherwise no one has any hope of really helping you. \$\endgroup\$ – Daniel Nov 15 '15 at 2:01

Not the answer you're looking for? Browse other questions tagged or ask your own question.