Posted: 2/28/2015 9:59:53 PM EDT
|
Need to replace some blown capacitors in a pair of computer monitors, where is the best place to source these parts from?
I can't remember if they were 820 or 850uF 25v and I only need like 6-10, not 1000. I know I can get kits for $15 but that seems steep for 6 little caps. Thanks |
|
There are a few reasons why the caps blow in the first place. Overall, heat is the culprit, but there are a few factors to consider.
1. Physical size: The larger the can, the more heat it can dissipate. 2. ESR: Equivalent Series Resistance. The higher the ESR, the more power is lost as heat inside of the capacitor, needing to be shed by #1. 3. Electrolyte formula: Some electrolyte formulas withstand temperature better than others - both how high of temp, and for how *long* they can withstand that temp. Keep in mind that as operating temperature goes down, the lifespan goes up HUGELY. So even if they're rated for a "measly" 3,000-7,000 hours @105C, if you're running them at sane temps, they will last exponentially longer. A combination of a large can, low ESR, and long-life electrolytic is what you're looking for. If you want to do it right, throw something like some Panasonic FM or Nichicon HE capacitors in there, with preference to the Panasonics. Get the same diameter, same working voltage as the replacements, and at least as high of capacitance. In every monitor I've ever re-capped, I've had room to go at least one size taller on the replacement caps than the original units, which means both a larger can, and lower ESR. When you see a "bank" of capacitors of equal size, near each other, if even one is popped, REPLACE THEM ALL. Mouser or Digikey should have the Panasonic FM series. If you follow those guidelines, the new caps will outlast the rest of the monitor. If you buy cheap caps (like those at Rat Shack), you'll be getting high ESR, and low-temp/low life electrolytes, and you may just end up doing it again before long. Your original caps failed because they were cheap, don't make the same mistake again. 
|
|
Their title is misleading, there are no motherboards that use 25V caps. But, if they aren't knockoffs and are the appropriate height and diameter for his monitor, KZM series are straight-up good stuff. |
|
Thanks for all the replies.
The caps blew because of Chinese industrial theft. My brother (the computer guy) found out that during the time frame that these monitors were made, the Chinese were using capacitors made with a stolen formula, except the idiots stole the wrong formula and the caps lasted a fraction of their intended life. So properly manufactured parts should be fine without me going too higher rated parts. And all the Radioshacks are empty here too. |
|
Quoted:
Thanks for all the replies. The caps blew because of Chinese industrial theft. My brother (the computer guy) found out that during the time frame that these monitors were made, the Chinese were using capacitors made with a stolen formula, except the idiots stole the wrong formula and the caps lasted a fraction of their intended life. So properly manufactured parts should be fine without me going too higher rated parts. And all the Radioshacks are empty here too. I doubt it. The time frame when that was a thing was 15 years ago, is your item that old? These days, people just use cheap, under spec caps. Or manufacturers put amazing claims on data sheets, but don't actually live up to them. Save fifty cents on caps, item still makes it out of warranty, profit. That seems to be the philosophy. |
| I have gone up on capacitance and voltage, but not huge jumps. I'll use a 470 in place of a 330, and for anything over 25v I use a 50v cap. Also a good idea as previously stated to replace ALL the caps not just the bad ones except the one giant battery sized cap as it never goes bad. I work with an electronics recycler buying recycled monitors for repair, I've done about 80 recaps in the past few months. I'm actually posting this on a 28" Hanns-G high def that cost me $25 next to a $10 24" Acer, once you do it and see how easy it is you can make a good side job out of it. |