I have a computer motherboard with 5 blown caps. 4 of them are 2200uf 6.3v and have KZJ printed on them. The remaining one is 1800uf, 6.3v and also has KZJ printed on them.
Should I look for capacitors that have exactly the same marks (1800/2200, 6.3v and KZJ)?
Does the KZJ mean anything…or perhaps is it a brand?
The 1800uf is slightly smaller in diameter. Can I replace it with a 2200uf?
You can in some applications use a larger value cap, but there are some applications that will require the correct cap for the circuit to perform as designed.
For a motherboard you should probably stick to the same values, KZJ is just be the brand so ignore that.
Just make sure to get some that are low ESR and 105.C rated, Stick to panasonic and rubycon imo and I’d also avoid buying from china as you could end up with fake ones.
Also, the voltages don’t have to match exactly. As long as the voltage rating is at least as high as the original caps, you’re okay. The only potential issue with using a higher voltage capacitor is that it may be physically bigger (ie fitment could be a problem).
Capacitance doesnt need exact. even 1000uf instead of 2200 & 1800 will work but reduced life or not stable.
some high quality low ESR 1000uf caps are much more better than high ESR 2200uf caps.
voltage not to be same but must be at least 6.3V. you can use 10V or 16V rated caps too but they are bigger than 6.3V caps if same capacity.
some years ago I replaced 3 blown 2200uf 6.3V caps with locally brought 2200uf 10V caps. board works and died again after few weeks. then I replaced those caps again with 2200uf 6.3V NICHICON caps that I pulled from another dead motherboard. they worked few years without any issue till motherboard died due to another fault.
Here is a pic of 4 1800uF caps at 16V They might be larger than what you have, but they would be OK if they physically could fit. Where did they come from? An old motherboard that I had put aside. I save a lot of old electronics for that very purpose. And the parts are organized and easily identified when they are needed.
Just last night I replace a brick for one of our cordless phones with a brick from a Nokia cell phone from 10-12 years ago that I had put aside when I replaced it years. In fact I have a whole box of power bricks.
IMHO, I think that because you have 5 blown caps, there is another problem here. There is probably a common cause for all 5 to blow. Going out and spending money (and the effort to locate them) could be a waste. I didn’t actually say this, but I think it could be a whole lot easier to locate an old computer or motherboard for the parts. If they blow also, you are only out your time.
Actually, unless your motherboard is the latest and greatest, it would just be easier to replace it. Last year I bought a motherboard for a dual core AMD cpu from NewEgg for $15 after rebate. Works great.
Actually it depends on how they are blown… there was a period in time, about 10 years ago, where there was a epidemic of failed electrolytic capacitors, due to poor quality (the electrolyte was drying out prematurely if I recall correctly). It is quite common to see boards with a dozen or more of these capacitors all split on the top and leaking electrolyte. When you see this it is a good idea to change out all electrolytic capacitors with the same brand markings, even if they are not showing leakage.
There was a period in time, about 10 years ago, where there was a epidemic of failed electrolytic capacitors, due to poor quality (the electrolyte was drying out prematurely if I recall correctly). It is quite common to see boards with a dozen or more of these capacitors all split on the top and leaking electrolyte. When you see this it is a good idea to change out all electrolytic capacitors with the same brand markings, even if they are not showing leakage.
I get mine from Mouser if I know what I want exactly. I have had to buy quite a few over the years because I work on the occasional arcade machine. The last place I ordered them from is twisty wrist arcade…. but I don’t know if they have any caps you’d need. When I purchase caps I usually get more than I need of a certain quantity, and then some common values, and then I’ll usually have extra on hand when I need to fix something else.
Ebay might have some, but most places you buy caps from expect them to be shipped in priority boxes, so you’re going to end up paying $5-$7 in shipping. So it’s best to pad your order where ever you order them from to make it worth it. Oh and good luck finding anyone locally with a decent selection- radio shack carries a few, but good luck finding what you need there.
Mouser will have everything you need but it’s harder to navigate.
You’re searching for “Aluminum Electrolytic Capacitors” probably radial. Radial refers to the leg orientation, most caps people need have the legs at both ends. Also make sure to not whether your caps are bi-polar or not. Most likely they’re not. But be careful not to inadvertently order a cap marked “BP” if you don’t need one.
Also like has been said… it’s best NOT to go up or down in uF rating. In fact, I would never do it. It is possible but you have to know exactly what that cap does and the other components are up line or down line from it and a good knowledge of the circuit board you’re working on. The voltage rating is flexible… you can always go up in voltage, but never down. The only thing that changes is the size… which has never been a big deal for me, most of the time there’s plenty of room.
Because I have the ability, and resources, I would either use known good caps from a pull, or if it was a cheap motherboard, replace it.
I certainly wouldn’t go through the hassle of ordering replacements.
This thread got me looking at another computer I have, hunting for spare caps to harvest for this project. Guess what? It has blown caps as well!
The caps in my second computer were harder to identify as they were bulging from the bottom. I never would have known it, but one of the links ya’ll posted talked about caps that are leaning as being a sign that the bottom has blown. Sure enough they were.
I have two other non-working computers that I will be checking…I’m a bit of a pack rat :8)
kzj is the series.
they are a ultra low esr type.
they failed because of heat and ripple they were exposed to and lack of quality.
check your power supply too.
badcaps store or digikey for small qty orders.
Checked the local Radio Shack but they had limited items. Found some Rubicons on ebay for cheap…about 56¢/ea…enough to do a few computers…hope they work out. A few questions:
1) I remember in electronics shop class way back in the day we had to use a little aluminum heat clamp/sink for certain components that couldn’t withstand the soldering iron’s heat. Should I use one on these caps?
2) I’ve heard touching/desoldering capicitors can be very dangerous. Are these too small to worry about?
3) Should the excess wire from the caps be trimmed before or after soldering?
