Hi All,
I have a general question about capacitors.
I have a PC monitor that stopped powering up. Instead of disposing of it and purchasing a new one, I’d like to see if I can fix it.
After opening it up, I found that the capacitors powering the video processing circuit have a slight bulge. These are the larger blue capacitors in the pictures below. You can clearly see the bulge — it’s not severe enough to have leaked or popped, but it’s noticeable, so I suspect these capacitors are probably the culprit.
The blue capacitors are rated at 10V 1000µF. I ordered replacements with the same rating (10V 1000µF), but they are much smaller in physical size. I’m planning to replace these capacitors to see if that gets my monitor working again.

 

Bad capacitors are a common failure mode.
If the capacitance value and voltage rating are the same you can go ahead and do the replacement. Make sure that you install it with the correct polarity.

It does not hurt to go with a slightly higher voltage rating.

 

Great, both are 10V 1000uF, but as the original Cap was much larger, I was wondering its there element in the specification i was missing.

 

i would not worry about that... materials science is not marching, it is sprinting. products done years ago are always bulkier...

 

The lead spacing does not look the same. That should not matter if you can still fit the new capacitor in the PCB holes.
A physically larger capacitor (or higher voltage) might have wider lead spacing. Nevertheless, this is not critical.

What has not been mentioned is the ESR (equivalent series resistance) of the capacitor. A higher ESR might cause the capacitor to heat up and hence fail sooner.

 

Well, it's an old monitor, if it can give a little more life, i would be happy

 

The fact that new-type capacitors are much smaller than old-type capacitors should not be surprising.

There may be several reasons – old capacitors may be designed to operate with higher currents. Or it could be that the manufacturer saved on materials, and the new type of capacitor will not be able to operate with a 10V voltage.

Since capacitors were used in the monitor, it seems they were used in the SMPS converter. In such circuits, capacitors with low ESR are required. If you don't know the ESR of the new capacitors, the advice would be to use capacitors with a larger capacitance than the old ones. Even better would be to connect two capacitors in parallel instead of the old one

 

I swapped the capacitors and the monitor is back working now