Why do Caps fail so often?

[Bishop]

I've started repairing flat panel monitors in my spare time just to see what makes them tick. So far I've fixed three monitors and all have been bad caps.

Does anyone know why caps fail?

Maybe it's me but I see too many flat panel monitors headed for the trash can. I know it's too costly for computer shops to repair because of the time/cost issue, but if this is the future of monitors, were all in trouble.

Manufacturer's can do better at design than than this.

Is it heat build up, lightning, power surges, or is just turning it can kill a cap?

Rod

[lucky13]

Re: Why do Caps fail so often?

I'd say heat build up due to a poorly designed power supply section.

Most of the time I see caps sitting on top of the heat sinks baking away....then there are the crap brands.

Problem is the new monitors are selling so cheap that people are attracted by the wide screen new monitors and no longer interested in having the old ones repaired.

[shadow]

Re: Why do Caps fail so often?

You are correct that manufacturers could design their products a bit better or at least use better components for the job.

However this costs money. I do not know anything about LCD monitors but with power supplies and motherboards, an extra couple of dollars would make a 'bad' product significantly better in most cases.
However when items are mass produced, every cent saved means a fair bit of extra profit in the long run.

With respect to why capacitors fail. There are many reasons.

1. Crap components are used. Cheap capacitors that have exaggerated specifications and/or are plain junk are used to save some cash.
2. Skimped components, less components are used than what would be recommended. Less components = cheaper product.
3. Heat build up, heat kills capacitors. Clearly seen in Dell SFF PC's, even top Rubycon MBZ capacitors fail in those PC's.
4. You mentioned lightning and power surges. These can kill capacitors. However not many things can survive a lightning strike without the appropriate equipment to protect them. You are basically praying that not everything is killed in your house unless you have a lightning suppressor of some sort fitted in your house.

[370forlife]

Re: Why do Caps fail so often?

I got a little 60mm delta fan sucking air out of the back of my Westinghouse 22". The psu board is a delta with all capxon. Doesn't get too hot, but the fan is just a reassurance. I run fan off of a 9v battery, runs forever and is not loud at all.

[lucky13]

Re: Why do Caps fail so often?

I got a little 60mm delta fan sucking air out of the back of my Westinghouse 22". The psu board is a delta with all capxon. Doesn't get too hot, but the fan is just a reassurance. I run fan off of a 9v battery, runs forever and is not loud at all.

I've seen many delta boards using Crapxon and they bulge like crazy. The fan may help especially many LCD monitors are quite hot once it's been on for awhile. I've seen some monitors got so hot after a few hours that you cannot pick it up by the metal frame inside (guess that's why they have plastic cabinets).

[PlainBill]

Re: Why do Caps fail so often?

One thing to keep in mind is the LCD display industry is about where the TV manufacturing industry was in 1965. The design of these things are evolving like crazy.

One serious problem holding things back is the lack of feedback from consumer to manufacturer.

PlainBill