I have a number of LCD monitors that have all suffered from a particular fault at one time or another -- swollen and possibly dried out 105C low ESR filter caps on the 12V and 5V rails of the power supply (switchmode).
When I purchased the capacitors for the second monitor, I bought enough to do the rest (and then some).
Recently one monitor died, and then a day or so later another one did.
The first one I opened up had a combination of capacitors fail I had not seen before. Only the 5V filter caps were swollen, and in fact leaking. Also they were ones I had replaced about 3 months earlier.
When I grabbed the replacement capacitors, I noticed that one of the new and unused ones was already sporting a bulging top, and measurements revealed it had a much higher then expected ESR. The other three new ones were fine.
I can only imagine that one or both of these new capacitors I had installed three months earlier had been faulty.
These capacitors were unused, and stored in very benign conditions.
The second monitor had the typical pattern of failure with both the 12V and the 5V filter caps affected by heat/age, and was one I had not repaired previously. So it was just a coincidence that two failed in two days.
The place I got the capacitors (Jaycar) is unfortunately staffed by people who don't care. I showed them the new capacitor and they just shrugged. I would have expected them to at least say "that's odd" or something.
The capacitors in question were 10V 1000uF low ESR. I have found that 16V 1000uF low ESR caps have a much lower ESR (about 40% lower) and also have a form factor that better fits these boards, so the second monitor got these.
When I purchased the capacitors for the second monitor, I bought enough to do the rest (and then some).
Recently one monitor died, and then a day or so later another one did.
The first one I opened up had a combination of capacitors fail I had not seen before. Only the 5V filter caps were swollen, and in fact leaking. Also they were ones I had replaced about 3 months earlier.
When I grabbed the replacement capacitors, I noticed that one of the new and unused ones was already sporting a bulging top, and measurements revealed it had a much higher then expected ESR. The other three new ones were fine.
I can only imagine that one or both of these new capacitors I had installed three months earlier had been faulty.
These capacitors were unused, and stored in very benign conditions.
The second monitor had the typical pattern of failure with both the 12V and the 5V filter caps affected by heat/age, and was one I had not repaired previously. So it was just a coincidence that two failed in two days.
The place I got the capacitors (Jaycar) is unfortunately staffed by people who don't care. I showed them the new capacitor and they just shrugged. I would have expected them to at least say "that's odd" or something.
The capacitors in question were 10V 1000uF low ESR. I have found that 16V 1000uF low ESR caps have a much lower ESR (about 40% lower) and also have a form factor that better fits these boards, so the second monitor got these.