Noob needs help choosing replacement caps (experts please help)

[Stevevil]

Hi everyone, I'm new and I've decided to repair my IZ3d 22" monitor. It was making high pitched noises when running last time I plugged her in over 2 years ago and it had been getting progressively worst. I knew I had probably blown caps or nearly (although it was still working when I retired it).

I've disassembled the monitor and identified the bad caps in question...
<drum roll>
Capxon

Yea.

So help me please. Here's the specs of what I'm replacing but I have no idea what to replace them with (since I sure don't want more Capxon).

Capxon Black 2200uF 10v KF series 105c P711 vent 20mm x 10mm
Cap Size Ripple Impedance
2200uf 10x20 1380 0.090

Capxon Black 100uf 25v KF series 105c P710 vent 11mm x 6.3mm
Cap Size Ripple Impedance
100uf 6.3x11 265 0.5

Capxon Green 2200uf 10v KF series 105c P722 vent 20mm x 13mm
Cap Size Ripple Impedance
2200uf 13x20 1750 0.041

I don't know how important it is to match the ripple and impedance.
Where should I buy them?
What brand should I get?
Can anyone identify the exact 3 capacitors I need to buy? Pretty please?
I know it's important to get the uF and voltage right but since it's a monitor if the other stuff is important and I don't get it right, it very may manifest in pixel or color artifacts.

Much appreciation for anyone who is willing to help me.

[Pentium4]

Re: Noob needs help choosing replacement caps (experts please help)

Capxon Black 2200uF 10v KF series 105c P711 vent 20mm x 10mm
Cap Size Ripple Impedance
2200uf 10x20 1380 0.090

Use these http://www.digikey.com/product-detai...1751-ND/589492

Capxon Black 100uf 25v KF series 105c P710 vent 11mm x 6.3mm
Cap Size Ripple Impedance
100uf 6.3x11 265 0.5

Use these http://www.digikey.com/product-detai...1545-ND/756061

Capxon Green 2200uf 10v KF series 105c P722 vent 20mm x 13mm
Cap Size Ripple Impedance
2200uf 13x20 1750 0.041

Use these http://www.digikey.com/product-detai...2357-ND/613718

You want to match or increase ripple ratings. Capacitance can be a little lower in some cases as long as the ripple rating is matched or exceeded. The impedance will be close enough with those caps, and they will be much more reliable.

There should be more value of caps in that PSU, like little 10uF-47uF 50V caps. If these are CapXon you will want to replace them too, they tend to dry out and cause start up issues

[lexwalker]

Re: Noob needs help choosing replacement caps (experts please help)

Capxon Black 2200uF 10v KF series 105c P711 vent 20mm x 10mm
Cap Size Ripple Impedance
2200uf 10x20 1380 0.090

Rubycon YXJ, 10YXJ2200M10X20, size=10x20, ripple=1400, impedance=0.046

Capxon Black 100uf 25v KF series 105c P710 vent 11mm x 6.3mm
Cap Size Ripple Impedance
100uf 6.3x11 265 0.5

Nichicon HE, UHE1E101MED, size=6.3x11, ripple=340, impedance=0.22

Capxon Green 2200uf 10v KF series 105c P722 vent 20mm x 13mm
Cap Size Ripple Impedance
2200uf 13x20 1750 0.041

Nichicon HE, UHE1A222MHD6, size=12.5x20, ripple=1900, impedance=0.035

I don't know how important it is to match the ripple and impedance.

Preferably almost the same specifications. Can also choose those with higher ripple handling and much lower impedance.

Where should I buy them?

Try either RS Components, Mouser, Farnell and/or Digikey.

What brand should I get?

The usual ones like Panasonic, Nichicon, Rubycon, Sanyo/Suncon and Nippon Chemicon.

[Stevevil]

Re: Noob needs help choosing replacement caps (experts please help)

Thank you both for your help. If I understand your responses correctly I gather the "ripple" is how much variance in volt/amp the cap can tolerate? And that's why it's ok to go higher but not lower?

I guess Impedance would be the cap's resistance, also the reason it is ok to go lower but not higher?

Also, I read on another site these caps are low ESR, are the replacements you guys suggested? (or does it matter?)
Also, I've heard people talking about switching and non-switching caps (or something to that effect). Is this something I need to worry about too? If so, how can I find out, because there was no mention of that in the specsheet on the Capxon website.

There ARE other Capxon caps on the board I pulled from this monitor but they all appear undamaged so far. I am not terrific at soldering and if I replace them all we're talking about a dozen instead of just four. Do you guys agree Pentium4 about going ahead and replacing them all instead of just the bad ones? I know Capxon has a bad reputation but do they suck so bad that all of their caps fail? Will using more slightly off spec caps have a cumulative effect causing problems?

Also, can anyone else confirm what these two guys have told me so far? I'm sure they are waaaaay more knowledgeable than I am, but if I get this wrong and fry my IZ3D monitor I won't be able to get another one since they stopped manufacturing them 2 years ago.

[Pentium4]

Re: Noob needs help choosing replacement caps (experts please help)

Thank you both for your help. If I understand your responses correctly I gather the "ripple" is how much variance in volt/amp the cap can tolerate? And that's why it's ok to go higher but not lower?

Correct

I guess Impedance would be the cap's resistance, also the reason it is ok to go lower but not higher?

Correct

Also, I read on another site these caps are low ESR, are the replacements you guys suggested? (or does it matter?)
Also, I've heard people talking about switching and non-switching caps (or something to that effect). Is this something I need to worry about too? If so, how can I find out, because there was no mention of that in the specsheet on the Capxon website.

Yes they are low ESR caps, higher ripple ratings, and much higher heat tolerance

There ARE other Capxon caps on the board I pulled from this monitor but they all appear undamaged so far. I am not terrific at soldering and if I replace them all we're talking about a dozen instead of just four. Do you guys agree Pentium4 about going ahead and replacing them all instead of just the bad ones? I know Capxon has a bad reputation but do they suck so bad that all of their caps fail? Will using more slightly off spec caps have a cumulative effect causing problems?

The reason I say replace them all because not only are CapXon one of the worst brands, but monitor PSU's are passively cooled, so they run hot. I have seen dozens of small CapXon caps fail (no signs of bulging) either due to low capacitance, extremely high ESR (20+ ohms) or fail open circuit. The start up cap (Probably 47uF 50V or 22uF 50V) should at least be replaced. If you don't want to do this repair again, replace ALL of the CapXon, but you can leave the big 400 or 450V cap

[Stevevil]

Re: Noob needs help choosing replacement caps (experts please help)

I see. I definitely don't want to do this repair twice. Especially after reading the BC FAQ talking about damaging the board by pulling off/on caps multiple times. I want to get it right the first time. I'll count all the capxons when I get home and see what we're talking about here. I may ask for additional help locating the correct caps for the others once I get their specs (please be patient with me, as although I don't know much about capacitors, I swear I'm not a dummy... so I'll learn this stuff pretty quickly as you guys help me).
I really appreciate it!

[Stevevil]

Re: Noob needs help choosing replacement caps (experts please help)

Ok, I went back in the Capxon KF pdf and realized that there was voltage listed up top (I had tried to match using uF and size alone previously). Felt a little silly for not noticing this before.

Here's the actual ratings (according to the Capxon KF manual)...

Black 100uf 25v KF series 105c P710 vent 11mm x 6.3mm
Cap Size Ripple Impedance
100uf 6.3x11 370 0.35

Green 2200uf 10v KF series 105c P722 vent 20mm x 13mm
Cap Size Ripple Impedance
2200uf 13x20 1750 0.041

Black 470uF 35v KF series 105c P724 vent 20mm x 10mm
Cap Size Ripple Impedance
470uf 10x20 1200 0.065


but here's what I'm really not able to understand...
One of the bad caps has these markings:

Black 2200uF 10v KF series 105c P711 vent 20mm x 10mm

In the manual though the dimensions don't match. It listed this under 10v...

Cap Size Ripple Impedance
2200 13x20 1750 0.041
2200 10x25 1650 0.52

There was a 6v cap with 20x10 but I can clearly see 10v on the cap.
As you can see there's a huge difference in Impedance between the two models. Am I being too careful about matching the 3 catagories? I don't want to destroy my monitor since they don't make these anymore. Please advise...

Also, if anyone is willing to find me a good match for the first three now that I have the correct properties for those I would so appreciate it. I'm starting to understand capacitors a little better as I read through the forums but IZ3D went out of business in 08 and I'm very worried about choosing the wrong replacement and blowing it up for good.

[mariushm]

Re: Noob needs help choosing replacement caps (experts please help)

If there is room on the pcb, you can fit capacitors rated for higher voltage. For example, you can use 2200uF 16v instead of 2200uF 10v if it's cheaper or better in specs.

The ripple values and impedance do depend a bit on the can size, so by going with slightly higher voltage rated caps which are a bit fatter or taller, you can get better specs.

Don't go overboard choosing very low impedance capacitors, you should stick close to the old impedance value. As in... don't replace a capacitor with 0.15 ohm esr with a 0.05 ohm esr, it might cause problems.
You can (if you have no choice) even replace with capacitors that have impedance a bit higher than the old ones.. something like 5-20% extra.
Think about it : those capacitors started to fail months ago and their specs slowly diminished until they went so outside the specs that the monitor simply couldn't work with them. In addition, the values listed in those datasheets for Capxon could very well be a bit too "optimistic". So the circuit will tolerate quite a bit of impedance variation.

But you should have no problems finding capacitors with a bit lower impedance and lower impedance is better for longer life in that heat in the back of the monitor.


As for your last questions... sometimes manufacturers simply label 10v rated capacitors as 6.3v and other things like this, to fill holes in a series of capacitors. It could be that they're reusing 10v capacitors and selling them as 6.3v rated capacitors.

[PeteS in CA]

Re: Noob needs help choosing replacement caps (experts please help)

I guess Impedance would be the cap's resistance, also the reason it is ok to go lower but not higher?

Resistance (ESR) is part of impedance. Technically, resistance refers to DC resistance; impedance is DC resistance plus AC reactance (which varies with frequency; it's a vector sum, not simply adding, but that's probably TMI). If you're talking 1% or 5% higher, it will be OK. But lower impedance can cause other kinds of problems; I wouldn't go more than 25%-30% lower.

Also, I read on another site these caps are low ESR, are the replacements you guys suggested? (or does it matter?)
Also, I've heard people talking about switching and non-switching caps (or something to that effect). Is this something I need to worry about too?

The parts P4 and lex recommended are all low impedance ("ESR" = Equivalent Series Resistance).

"(S)witching and non-switching caps" refers to the type of circuit in which the caps are used. Switching power supplies - whether the grey (or whatever color) box into which the AC cord plugs or the DC-DC converters on your mobo - subject output capacitors to significant stress. P/S output capacitors must be low impedance, so the ripple voltage will be low, and must be rated for fairly high ripple current. Capacitors suitable for switching power supplies have lower impedance and higher ripple current ratings than general purpose parts.

If you try to use general purpose parts as output capacitors in switching power supplies the ripple may mess up computer operation, and the general purpose parts won't last very long. On the other hand, low impedance capacitors will usually work quite well (maybe with longer life) where a general purpose part is adequate.

[PeteS in CA]

Re: Noob needs help choosing replacement caps (experts please help)

BTW, don't feel bad about being a "Noob". We all start there.

[Stevevil]

Re: Noob needs help choosing replacement caps (experts please help)

As for your last questions... sometimes manufacturers simply label 10v rated capacitors as 6.3v and other things like this, to fill holes in a series of capacitors. It could be that they're reusing 10v capacitors and selling them as 6.3v rated capacitors.

I'm not sure I understand your answer completely (or maybe I didn't explain enough).

The capacitor on the board is marked 10v with the markings I specified and has the 10x20 dimensions (I measured them with a metal mm ruler) but the pdf that lists all the Capxon KF series only show the two I listed which neither match the dimensions of the actual 10v capacitor on the board. Either the document I'm referencing is out of date or there's something missing in the document (maybe a discontinued line or something?) Either way, the specs of the two listed 10v 2200 caps are quite different so I'm at an impass for choosing a replacement (do I trust either of the specs for this since it doesn't match either (dimension wise at least)).

I'm pretty sure I could fit a slightly larger (certainly taller) cap in that spot but the specs are my concern.

Here's the pdf I'm referencing for my values...

[Pentium4]

Re: Noob needs help choosing replacement caps (experts please help)

I have noticed that too with some CapXon capacitors, the datasheets are probably old. You don't need to worry though, the replacement parts don't have to match exactly 100% It doesn't make much difference if the caps are a little larger dimension or height wise as the ESR will usually only be marginally different, maybe 0.01Ω

[jetadm123]

Re: Noob needs help choosing replacement caps (experts please help)

Any possibility is that sometimes board manufacturers may ask for a "custom" size cap. This is done when you have a highly populated board and the existing size caps offered may not fit. Because the cap industry is so competitive, manufacturers will gladly accommodate you if you order their minimum amount.

[Stevevil]

Re: Noob needs help choosing replacement caps (experts please help)

Here's what I've picked out for replacements. Can someone knowledgeable please check my specs and see if I'm going to encounter any problems with my choices? Pretty please.
--------------
Original:
Black 100uf 25v KF series 105c P710 vent 11mm x 6.3mm
Cap: 100uf
Size: 6.3x11
Ripple: 370
Impedance: 0.35
-
Replacement:
Applications: General Purpose (100uF 25v)
Ripple Current: 290mA
Impedance: 250 mOhm
http://www.digikey.com/product-searc...ds=UPW1E101MED
-
OR I COULD USE: (Which would you use?)
-
Applications: General Purpose (100uF 25v)
Ripple Current: 340mA
Impedance: 220 mOhm
http://www.digikey.com/product-searc...ds=UHE1E101MED
--------------
Original:
Green 2200uf 10v KF series 105c P722 vent 20mm x 13mm
Cap: 2200uf
Size: 13x20
Ripple: 1750
Impedance: 0.041
-
Replacement:
Applications: Automotive
Ripple Current: 1.75A
Impedance: 33 mOhm
Size: (12.50mm x 27.00mm)
I've checked and I have the extra verticle room
http://www.digikey.com/product-detai...MHD-ND/2597385
-
I have come to the conclusion that the listed impedance of 0.52 on that unknown capacitor must be a misprint. It's within 100 ripple and very close to the same size (albeit taller rather than fatter) but bet they meant to put 0.052
-
Working on that assumption I think the specs are close enough to the other 2200uF that I can use the same for that one too.
----------------
Original:
Black 470uF 35v KF series 105c P724 vent 20mm x 10mm
Cap: 470uf
Size: 10x20
Ripple: 1200
Impedance: 0.065
-
Replacement:
Applications: General Purpose
Ripple Current: 1.22A
Impedance: 52 mOhm
http://www.digikey.com/product-detai...0301-ND/266310
-
So that's it. I checked availability at mouser and I can order each of these with a minimum of 1 so that shouldn't be a problem.
Does anyone think these specs are too far off? What about the one I found two for?
Also, one of these says the "application" is "Automotive", what the heck is that about? Is that the wrong kind of capacitor? (because the specs look pretty close)
Also, are any of these capacitors I've picked out the wrong kind for a monitor power supply? Like I said, I know nothing about ESR and all that jazz (except what little you guys have told me about it) so I just want to make sure I don't mess up by going with the wrong "series" or something like that.
-
I Seriously can't express enough gratitude to those of you who have participated in my discussion so far. It's so important that people who have knowledge use it to help others and I'm so glad you guys feel the same. Thank you.

[Pentium4]

Re: Noob needs help choosing replacement caps (experts please help)

Original:
Black 100uf 25v KF series 105c P710 vent 11mm x 6.3mm
Cap: 100uf
Size: 6.3x11
Ripple: 370
Impedance: 0.35
-
Replacement:
Applications: General Purpose (100uF 25v)
Ripple Current: 290mA
Impedance: 250 mOhm
http://www.digikey.com/product-searc...ds=UPW1E101MED
-
OR I COULD USE: (Which would you use?)
-
Applications: General Purpose (100uF 25v)
Ripple Current: 340mA
Impedance: 220 mOhm
http://www.digikey.com/product-searc...ds=UHE1E101MED

Second option

Original:
Green 2200uf 10v KF series 105c P722 vent 20mm x 13mm
Cap: 2200uf
Size: 13x20
Ripple: 1750
Impedance: 0.041
-
Replacement:
Applications: Automotive
Ripple Current: 1.75A
Impedance: 33 mOhm
Size: (12.50mm x 27.00mm)
I've checked and I have the extra verticle room
http://www.digikey.com/product-detai...MHD-ND/2597385
-
I have come to the conclusion that the listed impedance of 0.52 on that unknown capacitor must be a misprint. It's within 100 ripple and very close to the same size (albeit taller rather than fatter) but bet they meant to put 0.052
-
Working on that assumption I think the specs are close enough to the other 2200uF that I can use the same for that one too.

Notice how it says "price break 300" You would have to order a minimum of 300, and I wouldn't use those anyways. I would order these:
http://www.digikey.com/product-detai...1510-ND/756026

Order them, and have fun recapping you may just become addicted

[cheapie]

Re: Noob needs help choosing replacement caps (experts please help)

Looks good. I'd use the second choice for the one with two possibilities.

[lexwalker]

Re: Noob needs help choosing replacement caps (experts please help)

Resistance (ESR) is part of impedance. Technically, resistance refers to DC resistance; impedance is DC resistance plus AC reactance (which varies with frequency; it's a vector sum, not simply adding, but that's probably TMI). If you're talking 1% or 5% higher, it will be OK. But lower impedance can cause other kinds of problems; I wouldn't go more than 25%-30% lower.

The parts P4 and lex recommended are all low impedance ("ESR" = Equivalent Series Resistance).

Very often I would use what I had in hand, and that includes capacitors that have much lower impedance/ESR than the original ones such as those Panasonic FM, Panasonic FR and Nichicon HE series (as I would stock them up normally). Rarely I would ever use lower series like Panasonic FC, Nichicon PS and Nichicon PW. For example, ocassionally I would use Panasonic FC to replace CapXon GL especially those 1000uF 10V ones (closest match to the original capacitors, can find them plenty in Samsung monitors) but often I would use Panasonic FR or Nichicon HE whenever I ran out of Panasonic FC. So far I've not had any return cases nor problems over the years.

If you try to use general purpose parts as output capacitors in switching power supplies the ripple may mess up computer operation, and the general purpose parts won't last very long. On the other hand, low impedance capacitors will usually work quite well (maybe with longer life) where a general purpose part is adequate.

Believe it or not, I have seen general purpose capacitors used on SMPS before. However they are usually accompanied with bypass ceramic capacitors in parallel (to create that "low ESR" effect). An excellent example would be Creative GigaWorks S750 speaker (which uses SMPS). Mostly CapXon GS and Su'scon SL series general purpose 85C capacitors on the secondary side, often placed very close to the heatsink! I was shocked at such travesty and replaced them all without any hesitation. Anyone who has/own these speakers should check it out themselves.

[PeteS in CA]

Re: Noob needs help choosing replacement caps (experts please help)

Very often I would use what I had in hand, and that includes capacitors that have much lower impedance/ESR than the original ones such as those Panasonic FM, Panasonic FR and Nichicon HE series (as I would stock them up normally). Rarely I would ever use lower series like Panasonic FC, Nichicon PS and Nichicon PW. For example, ocassionally I would use Panasonic FC to replace CapXon GL especially those 1000uF 10V ones (closest match to the original capacitors, can find them plenty in Samsung monitors) but often I would use Panasonic FR or Nichicon HE whenever I ran out of Panasonic FC. So far I've not had any return cases nor problems over the years.

I'm not saying substituting, for example, PW for HE or HE for PW won't work or will go . There's just some risks. In a PW for HE swap, ripple will probably be higher, the part will probably be hotter, and loop stability could be affected. If the end user doesn't stress the circuit, is good about cooling and keeping the whatever dust free, and the loop design allows lots of margin, the substitution will be invisible. In an HE for PW swap the risk is that loop stability could be affected. But if the loop design allows lots of margin, the substitution will be invisible. And even if a PW for HE swap results in an excessively hot cap, the consequence will be shorter life, not . In such a case, it might still be invisible to the end user, since the repaired whatever is likely several years old, and the end user might replace it with a newer whatever before the cap dies. So all in all, with a decent control loop design, risk is fairly low, and getting a repaired whatever back into the customer's hands is the big goal. Sometimes being a purist compromises the timeliness aspect of serving a customer

Believe it or not, I have seen general purpose capacitors used on SMPS before. However they are usually accompanied with bypass ceramic capacitors in parallel (to create that "low ESR" effect).

In a low current secondary output (e.g. the -5V or -12V in a computer P/S) this can work just fine, especially if it's on the O/P side of a 3-T regulator (e.g. 7905 or 7912). BUT it must have decent cooling. Some 30 years ago I tested an Astec P/S which used a UCC SM series (GP) cap rather than an RX series (low ESR) cap on a secondary O/P. It would have worked just fine, except the cap was surrounded by taller, hot, components. At room temperature on an open bench running at full load the cap case was >85C. I let Astec engineering know of what I found (they had a design group in Silicon Valley back then, and I knew the group's manager), and the next time I saw a sample of that model it had an RX series cap in that location. Needless to say, I don't think fly-by-night P/S mfrs would be so careful, or give a @#$% if such a problem were pointed out to them.

[lexwalker]

Re: Noob needs help choosing replacement caps (experts please help)

In such a case, it might still be invisible to the end user, since the repaired whatever is likely several years old, and the end user might replace it with a newer whatever before the cap dies. So all in all, with a decent control loop design, risk is fairly low, and getting a repaired whatever back into the customer's hands is the big goal. Sometimes being a purist compromises the timeliness aspect of serving a customer

Quite often many clients would use their hardware till they are broken/failed again. I've had stuff that came in that were previously repaired, and frequently the previous repairer did not really do a good job (e.g. using sub-standard replacements, not removing degraded glue in critical areas, bad soldering, etc). For many repairs, quite often time is important. Also I would not like those pending repairs stacking up while searching for suitable parts, comparing datasheets, evaluating parts to order and waiting for parts to be delivered.

In a low current secondary output (e.g. the -5V or -12V in a computer P/S) this can work just fine, especially if it's on the O/P side of a 3-T regulator (e.g. 7905 or 7912). BUT it must have decent cooling. Some 30 years ago I tested an Astec P/S which used a UCC SM series (GP) cap rather than an RX series (low ESR) cap on a secondary O/P. It would have worked just fine, except the cap was surrounded by taller, hot, components. At room temperature on an open bench running at full load the cap case was >85C. I let Astec engineering know of what I found (they had a design group in Silicon Valley back then, and I knew the group's manager), and the next time I saw a sample of that model it had an RX series cap in that location. Needless to say, I don't think fly-by-night P/S mfrs would be so careful, or give a @#$% if such a problem were pointed out to them.

Many of those general purpose capacitors in the Creative GigaWorks speaker that I've earlier mentioned previously, was right after the rectifiers and not only the output side of the linear voltage regulators. The main power section with 70V output also uses these general purpose capacitors, again right after the rectifiers! Just search for pictures of the speaker's internals and you will start to see what I meant. This speaker has little or no ventilation at all, and gets very hot/toasty inside quickly. That's not the only example. Occasionally I would find Rubycon YK (standard 85C) being used in SMPS section of certain power adapters. And the list goes on.

[PeteS in CA]

Re: Noob needs help choosing replacement caps (experts please help)

Hmmmm ...... maybe I should have said, "Fry by night".