capacitor value too high

[martyb]

so when 1000 uf caps red at 1150 uf does this mean capacitor should not be used and is this signs of a deteriorating capacitor or has it simply been made that way

[stj]

it's bad.
your meter is being fooled because it has electrical leakage between the pins internally.
this causes it to take longer to charge which fools the meter

[jons]

Specs

[stj]

yes, but thats VR, in the real world at room temperature your going to get -20% and +nothing%.
they are never over - i'v always suspected they are graded at the factory for special customers.

and i have seen many dozens of caps read over-value.
every one had internal leakage on my tester

he could charge it with a battery and then leave it for a while before checking it with a voltmeter but i'm telling you now that it's gonna self-discharge

[jons]

Oh yes, you're right in this aspect /still can't wake up/

[jiroy]

That's typical .. Lot of people confuse testing devices functions . Those are mainly a quick help to locate a problem , and accelerate a repair , but professionals repairers always have in their arsenal electronic circuits to test specific components under load . The more components circuits loaders you have , the more you're a professional .

[martyb]

i find generally that new caps read prety close and old caps read higher or lower than the ratings printed on them and any over 10 percent higher or lower i do not use asuming that they are going bad due to aging

[jiroy]

Momaka wrote a good thread about reconditioning capacitors . It may help you .

https://www.badcaps.net/forum/showth...ing+capacitors

[stj]

i recondition caps by throwing them in the bin

who was the member who used to throw them into a garden fire? LOL

[jiroy]

Originally Posted by stj

i recondition caps by throwing them in the bin

who was the member who used to throw them into a garden fire? LOL

Lol ....

[momaka]

Originally Posted by martyb

so when 1000 uf caps red at 1150 uf does this mean capacitor should not be used and is this signs of a deteriorating capacitor or has it simply been made that way

What stj said in post #2.
Usually higher capacitance means higher internal electrical leakage.

However, I also say it depends on the capacitor brand and series a little - as in, if you see around 15% or higher capacitance on a Chinese, Taiwanese, or Korean brand, it's probably a safe bet the capacitor's electrolyte has started to break down, causing internal leakage to go higher, and most likely will continue to go higher / break down further, leading to failure over time.

With the reputable Japanese brands, though, I treat them a little differently, since even a cap with higher internal leakage could still last longer than a cheap no-name garbage brand. For example, I still have some Nichicon HZ 6.3V 2200 uF with date codes beginning with H05 (from Xbox 360 motherboards) that are known to go bad over time. Almost all of my stock of these has gone bad. The very few that I still have that haven't bulged/leaked read well over 20% capacitance... and have been that way for a number of years. So clearly they are not to be used for anything long term. However, they still work good enough for testing out or temporary equipment recaps if I don't have enough caps. So even in their "half-failed" state, they have been more reliable than some no-name garbage brands.

Of course, the bottom line is: if you're doing a repair you want to last a while, don't use caps that have higher than 10% higher capacitance, especially any non-Japanese brands.

Originally Posted by stj

i recondition caps by throwing them in the bin

You're wasting good rubber feet!
https://www.badcaps.net/forum/showpo...&postcount=548
https://www.badcaps.net/forum/showpo...&postcount=585

Originally Posted by stj

who was the member who used to throw them into a garden fire? LOL

c_hegge
I couldn't recall the name, but I remember the avatar with the blue-colored lizard... so took a look through one of the early sticky threads and sure enough found out.

[petehall347]

in the old days capacitors could be something like -10 / + 100 percent .

[eccerr0r]

Need leakage tester. If you see high leakage with high 'capacitance' be sure to mark the capacitance suspect.
Note that pretty much all aluminum electrolytics leak some current, question is how much and how much is too much. The larger the capacitance the larger the expected leakage -- to an extent.