Should I use lower ESR capacitors?

[watdahel]

My LCD monitor started acting up where the screen is very dim and flickering from a cold start and eventually corrects itself after a few minutes. I opened it up and found three capacitors popped. I circled them on the image below. There are four others that appear OK but I'm wondering if I should replace them while I'm at it. The brand is CapXon and it doesn't have a great reputation. I'm wondering if the replacement capacitors need to be the same ESR as the original or would using the lowest ESR I can get better?

 

[Modelworks]

They are in a switching circuit by the looks of it so you need to use the same ESR or lower. Lower doesn't mean they will work any better if the first ones were chosen properly. What is more important is to get some with a higher temperature rating. That heatsink next to them is going to heat up that general area. Go for the highest voltage and temperature rating you can get that will fit in that area and still keep the ESR and farads the same.

 

[bryanl]

Lower than those defective capacitors have now? Of course, since they may currently measure several ohms ESR. 🙂 But much lower than when those capacitors were brand new? No, since they may be in an L-C filter (inductor-capacitor filter) circuit, and very low ESR in such filters can result in ringing because the ESR normally dampens it. Try to get replacement capacitors of equal or higher ripple current and approximately the same ESR. High quality brands, such as Nichicon, will last much longer, even if their ESR ratings are a few times higher. One of the capacitor manufacturers mentioned in their catalog or application notes that the voltage rating should not be far higher than the working volage, but I believe they specified 5x the voltage as the upper limit, and double the voltage will be fine.