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I am repairing (trying to repair) my TV.

I found 1 capacitor 25V \$1500\mu\$F which i think is bad (it has some weird shape at top) I don't have any capacitors with that value but I have some similar to that

  • 25V \$470\mu\$F x3
  • 35v \$1000\mu\$F

Can I replace the bad one with this 35V \$1000\mu\$F, or can I combine them (serial or parallel)?

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closed as off-topic by Nick Alexeev Oct 22 '14 at 16:57

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?" – Nick Alexeev
If this question can be reworded to fit the rules in the help center, please edit the question.

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If you put your three 25v 470uF caps in parallel, you'll get a 25v 1410uF cap with 3 times the current rating and 1/3 of the ESR (equivalent series resistance) of the individual caps. Depending on the application, this will be close enough capacitance (original tolerance is probably +/- 20% or so) and the lower ESR could be nice too...unless your jerry-rigged setup dwarfs the caps' ESR with its own actual resistance.

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  • \$\begingroup\$ So, if i connect my 3 capacitors 25v 470uf in parrallel, it would be good replacement for the bad one? \$\endgroup\$ – Ricky Oct 22 '14 at 17:01
  • \$\begingroup\$ Probably. If you keep the leads short, it might even work better than the original. Not that it would be noticeable though. \$\endgroup\$ – AaronD Oct 22 '14 at 17:44
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If you combine capacitors in parallel, their value will add.

(C1 + C2 = Ctotal)

  • 2x 1000uF capacitors in parallel will be equal to a single 2000uF capacitor.

If you combine capacitors in series, their value will divide:

(1/C1 + 1/C2 = 1/Ctotal)

  • 2x 1000uF capacitors in series will be equal to a single 500uF capacitor.

You should be able to replace the faulty capacitors with any that have:

  • The same (or higher) voltage rating
  • The same capacitance (with more knowledge of the circuit, it is possible that other values could be used)
  • The same polarity

Replacing these can be pretty dangerous (read: physical harm could definitely result) unless you know what you are doing, though. Make sure to unplug the TV, and also discharge the capacitors before removal.

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Your original capacitor is very likely bad. I had the exact same problem on one of my TVs and I repaired it by replacing the capacitor. Your new capacitor(s) must have the same or higher voltage rating (i.e. 25V or higher) but should have the same capacitance (\$1500\mu\$F).

You can achieve a \$1500\mu\$F capacitance with one \$1000\mu\$F capacitor in parallel with a pair of \$1000\mu\$F capacitors in series -- the series capacitors have an equivalent \$500\mu\$F capacitance, and the parallel combination of that \$500\mu\$F and \$1000\mu\$F capacitance adds to \$1500\mu\$F.

schematic

simulate this circuit – Schematic created using CircuitLab

It would probably be easiest to just buy a \$1500\mu\$F capacitor rated for \$\geq 25\$V, though, since the PCB will only have space for the one original capacitor. They are pretty cheap on Amazon.

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