Why replace only 1K or higher

[axlmastr]

I've read every inch of this forum and came to a basic conclusion that you recommend replacing caps around 1K or above. I determined many of the boards and power supplies I possess have the visible disease described in the value range most mentioned at this site. I am only curious for clarification purposes because I have boards, for example, with Chhsi caps down to 10uf @ 25V. Should I replace the 470, 68, and 10s or just the 1200 and 1500 values? Please clarify because i have about 25 of one board to do and 5 others that have some values below 1K in Lelon, Teyeh, etc. BTW I thought I was the only one three years ago finding badpower supplies with blown main caps! Thanks for making me feel akin to others with the same damn problem.

P.S. I'm not a "tree-hugger" or anything like that, but what happens to all of this cheap Communist Chinese produced comsumer electronics that look pretty, but only last a short time. It satisfies the demand for instant gratification of the North American consumer, but what happens when it's crapped out and the consumer only knows to throw it out. Throw it out where? This is bad ju-ju people. We as consumers have created our own worst nightmare. The Chinese say, "why repair, just buy a new one". (with a smile on their face) We have sucker written on our face because we are enslaved by greed to the Chinese and are at their mercy. Wake up! The American Dream is not American anymore!

[kc8adu]

Re: Why replace only 1K or higher

there are known bad caps in 330 and 470
like anything chssi,hermei,g-luxon,ect.
and i agree on the throwaway aspect.
i am waiting for this to bite us in the ass.
i rebuild antique stuff and get better service than any plastic crap.
my home a/c is a 40 year old frigidare made here in dayton.
my sw reciever is an r-390a.
i watch the news in the morning on a 62 magnavox round screen color combo thats 8 feet long and weighs 300lbs.
my stereo is a fisher 400.
and the pc i am typing this on is a msi 694d dual 866 that was free due to you guessed right...bad caps.china=crap.i will spend my money rehabbing good old well built stuff.

[axlmastr]

Re: Why replace only 1K or higher?

@kc8adu I'm with you on repairing the antiques. I get better service out of the old crap as well. I have always been a "fix-it not chuck it" kind of person. I still have some dinosaur P1 comps floating around and running 24/7 for basic office apps. The oldest currently is a Packard Bell Tower P133 I purchased new back when I didn't know about proprietary crap, but all in all it is still running with its original Quantum Fireball HD. Aah the nostalgia! Anyways, If you were to recap 25 machines to put back into corporate class service as everyday desktops (IBM A40 NetVistas for ex.) would you replace below the 1k value or would I be safe? I don'rt want to have to de-install again to replace those small boogers.

[kc8adu]

Re: Why replace only 1K or higher

on some of the netvista boxes there are a bunch of 330@6.3 that are always bad.
post a pic of your board.

[bushytails]

Re: Why replace only 1K or higher

I posted some photos of an exploded 100uf Rulycon a while back...

--Randy

[AK0R]

Re: Why replace only 1K or higher?

Anyways, If you were to recap 25 machines to put back into corporate class service as everyday desktops (IBM A40 NetVistas for ex.) would you replace below the 1k value or would I be safe? I don'rt want to have to de-install again to replace those small boogers.

My rig in 1978:
1st transmitter: Heathkit DX-60 + crystals (later bought a VFO)
1st receiver: Hallicrafters SX-122
These were my dad's back in 1960. He gave these to a neighbor getting started in radio. As far as I know, they still work (as of 1993).

As for the capacitors, crap is crap, no matter what the value. The small value caps just have more margin to failure (e.g., 25 VDC on a 5V circuit). If you already have the board out, why not spend the extra buck or two and replace all the crap caps? Presumably, you aren't paying for the caps, the business is. If you own your own business, and charge for the repairs, then you have to weigh the small additional cost against your business reputation. Personally, I'd rather be known as a business that fixes it right the first time, even if it means trying to negotiate for the cost of the extra caps, or having to eat the cost this time, but being more knowledgeable for the next time.

[axlmastr]

Re: Why replace only 1K or higher

@kc8adu

I'll get a pic posted for this board this weekend. It seems that the caps are of mixed brands! The 1500uF are Panasonics but the 1200uF close by are Chhsi.
@AKOR
I don't really want to recap the whole board since I keep finding in the forum that the suggestion is replace all that have vents on top or around 1000uf or higher.

BTW I just came across an IBM 300PL tower from a nice old lady who surfs the internet. It has an Intel board with riser. Caps near the PII slot are Nichicon while there's three (3) Chssi 560uf 25V nearby (next to two toroids) that are doming. The machine came to me with a 56K Winmodem failure after a T-storm. This was one of the many off-lease machines that became available at the local white-box dealers here. They got 2 1/2 years out of a $129 machine. Just recycling the old antiques one machine at a time.

[willawake]

Re: Why replace only 1K or higher

I keep finding in the forum that the suggestion is replace all that have vents on top or around 1000uf or higher.

in many cases you will get away with replacing 1000uf and above, the board will be totally stable. We have seen advice to go as low as to replace the above 470uf. that rule does not take into account the 330uf 25V seen on some boards which are fat and have vents and should be replaced. the smaller value caps can indeed cause stability probs in the board anyway on occasion

it is a factor how much money you want to spend on the project. i usually replace the 1000uf and above and if there is some fat say 330uf 25v with vents then i replace them also. in your case the 560uf 25v are a candidate for replacement. if the board still has stability probs then i would look into replacing the smaller caps.

in the end there is no real rule. like akor said all crap caps should go and then you will have problem free for years. otherwise if you are on a budget then replace the above 1000uf, replace also the fat caps which have smaller value like the 560uf. do memory and stability tests and see if ok

i have seen us robotics internal after a lightnight storm with a small component broken, under the cover of the pci card. computer would not boot with the pci card in

[Neo2_000]

Re: Why replace only 1K or higher

The high voltage rating of the smaller value caps may provide a certain amount of failure immumity by way of overkill. Having said that, like kc8adu if I encounter certain brands of caps such as chhsi, I treat them with suspicion as I have seen these exhibit physical failure.