Identifying ceramic capacitors

[l0cke]

I am currently fixing the power supply in a gateway monitor. I am replacing all of the caps in the psu, but these two confused me.

One says:
12J
3KV
JNC

The second says:
N3
3KV
SEC

These are part of the inverter circuit for the back light. They where close together but do not read the same thing.

I've looked up several guides on google about identifying caps, but I still can't seem to find out the actual value of these.

Thanks

 

[PottedMeat]

3KV is the voltage rating.

12J means 12 picofarads

N3 - I have no idea.

JNC/SEC may be temperature tolerances/ratings.

CCFL transformer output capacitors usually look like this:

http://search.digikey.com/scri...etail?name=445-2758-ND

 

[dporter]

10cke,

Did you ever find where to get those capacitors? I'm having the same issue. I just need to replace the ones with 12J, 3kV, JNC on them. I've found the ceramic capacitors with 3,000 volts but I'm not sure which uf to get.

Let me know what you found out I appreciate it.

 

[Check]

good job resurrecting a thread that has been long dead.
a pm would be more suitable in the future perhaps?

 

[l0cke]

Judging by the number of PM's and emails I get about this problem I will say that there appear to be a lot of people searching for these capacitors and google links to anandtech.

The 12J 3KV JNC one can be replaced by Digi-key part number P9643-ND

I still don't know about the N3 3KV SEC one, but there appears to be no need to replace it.

 

[nico95]

Hi,
Hope its not to late to ask a question on such a old post. I have the same bad caps 12J 3KV JNC looks like its ready to burn up and the other one all ready has. Do I need to replace the other caps
N3
3KV
SEC
They look ok.
Since no one seems to nothe value of this one I was wondering if I can get away with no replacing it. Also Should I replace all the Electrolytes caps. I tested them all with a ESR meter all came out good, but the filter cap. Its a low ESR but a little higher than it should be. .73 and should be around .53. There where a few that had real high Capcitance(instead of 240 or 640 they where like 2400, but Im guessing it's possible because they where in circuit. My meter will test in circuit but it may still be throughing things off. I didn't test any of the ceramic caps. There are a couple of those as well. None of the caps looks bad excpet the 2 bad 12J's
Thanks in advance,
Nico

 

[ZippyDan]

good job resurrecting a thread that has been long dead.
a pm would be more suitable in the future perhaps?

I've always wondered what is the harm in resurrecting long dead threads. As long as you are adding (or requesting the addition of) information that is pertinent to the thread's original topic, what is the harm? In fact, to me a thread is just a way to organize related data together.

It has frustrated me several times when, for example, I search for some computer problem on google, and I find someone else having the same problem. As I follow the thread down, the problem is not solved, but then at the end I find someone chime in with the same problem, but new information and new symptoms. Then: Moderator> this thread is too old, locked and please start a new thread.

WTF? I can never find the new thread, so there I am following my only THREAD of evidence and I've been shut down by this silly rule.

 

[l0cke]

Hi,
Hope its not to late to ask a question on such a old post. I have the same bad caps 12J 3KV JNC looks like its ready to burn up and the other one all ready has. Do I need to replace the other caps
N3
3KV
SEC
They look ok.
Since no one seems to nothe value of this one I was wondering if I can get away with no replacing it. Also Should I replace all the Electrolytes caps. I tested them all with a ESR meter all came out good, but the filter cap. Its a low ESR but a little higher than it should be. .73 and should be around .53. There where a few that had real high Capcitance(instead of 240 or 640 they where like 2400, but Im guessing it's possible because they where in circuit. My meter will test in circuit but it may still be throughing things off. I didn't test any of the ceramic caps. There are a couple of those as well. None of the caps looks bad excpet the 2 bad 12J's
Thanks in advance,
Nico

I would replace all of the caps you can, unless you are going to get a new monitor soon. You can just replace the 12J 3KV JNC and it will work fine, but capacitors are not all that expensive so it is usually worth it to replace them.

As for the N3 3KV SEC, my monitor is still working fine with the original ones. Unless someone knows the value of them, you should be fine leaving them alone.

 

[PsiStar]

I've always wondered what is the harm in resurrecting long dead threads. As long as you are adding (or requesting the addition of) information that is pertinent to the thread's original topic, what is the harm? In fact, to me a thread is just a way to organize related data together.

It has frustrated me several times when, for example, I search for some computer problem on google, and I find someone else having the same problem. As I follow the thread down, the problem is not solved, but then at the end I find someone chime in with the same problem, but new information and new symptoms. Then: Moderator> this thread is too old, locked and please start a new thread.

WTF? I can never find the new thread, so there I am following my only THREAD of evidence and I've been shut down by this silly rule.

I concur ... even if the "electronics" is from 1910. Some moderators have a need to go on a power trip. Better would be if a moderator could re-name the thread by adding information per the thread's discussion??? I apologize for going off topic.

Per the thread's title, & looking for the part ... round brown caps with 2 leads off are also ceramic. I have to admit that I did not know that they failed ... ever!

The N3 may be a temperature curve. The "N" suggests (as I vaguely remember) a negative temperature spec. Vaguely enough that i don't remember if the capacitance goes up or down versus temperature!!

 

[nico95]

Thanks for the info form all 3 of you
I guess I will try to replace the other Electroite caps. I called DigiKey but htey didn't have any LOW ESR caps in the Values I needed. I will have to check another place. Would I be ok not touching the regular brown ceramic caps then? Just try and replace the regular Electrolite ones instead. Once I find them
Thanks again,
Nick

 

[sender87]

same problem here with a vizio vmm26 lcd power supply but my blown up caps says 12j 3kv jnc and c3d 3kv jnc i already have the replacement for 12j but i cant find any info on the c3d one

 

[l0cke]

same problem here with a vizio vmm26 lcd power supply but my blown up caps says 12j 3kv jnc and c3d 3kv jnc i already have the replacement for 12j but i cant find any info on the c3d one

Just checked to see if this thread was still kicking around, looks like it is!

Unfortunately I can't help you with the problem, I haven't improved much since 2008. If no one else here knows the labeling used maybe you should try another electronics forum? I can recommend http://www.reddit.com/r/askelectronics

 

[sm625]

People no doubt find threads like this while googling for "12J", "3KV" etc.

Post some pics of your parts. That makes it much easier to identify them.

Also, if you can remove the parts without damaging them there are quite a few ways to measure their capacitance. I used to insert them into an RC timer circuit then calculate the capacitance from the resulting frequency. Nowadays I just use a capacitance probe.

 

[Abwx]

N3 is 0.3nF , that is 300pF....

 

[Sanders285]

I know this is an old thread but, I have a question about ceramic capacitor ID markings.
C
3D
3KV
JNC
The capacitor is from a Hanns-G HSC1041 LCD monitor power supply. I would like to identify the value of this capacitor. I would like to replace the original that went up in smoke on the power supply board.

 

[Harvey]

I know this is an old thread but, I have a question about ceramic capacitor ID markings.
C
3D
3KV
JNC
The capacitor is from a Hanns-G HSC1041 LCD monitor power supply. I would like to identify the value of this capacitor. I would like to replace the original that went up in smoke on the power supply board.

I'm an electronic design engineer, and those markings are confusing to me. I'm not sure, but from what I've found, they COULD mean:

C = Capacitor series. In this case, ceramic, possibly with other characteristics.

3D is confusing. Some manufacturers use it to indicate a voltage rating of 2KV (2,000 volts). However, the following marking, "3KV" would suggest a 3KV (3,000 volts)rating. If so, 3D may also indicate a value, probably in picofarads (pF).

JNC may be a manufacturer's name, but not one with which I'm familiar.

You may want to try contacting the manufacturer's tech support. If they'll help you, they probably have the best documentation. Also, check with local monitor repair techs.

Good luck.

 

[lozcool]

I know this is an old thread but, I have a question about ceramic capacitor ID markings.
C
3D
3KV
JNC
The capacitor is from a Hanns-G HSC1041 LCD monitor power supply. I would like to identify the value of this capacitor. I would like to replace the original that went up in smoke on the power supply board.

Did you find where you can get one from

 

[William Gaatjes]

JNC might be : Jya-Nay Co., Ltd

http://www.jyanay.com.tw/

That website is kind of very basic.

 

[sao123]

According to this thread at BadCaps,
http://www.badcaps.net/forum/printthread.php?t=10119&pp=20&page=4

The "N3 3KV SEC" capacitor is a 3pf/3KV capacitor.
Read the Post by MrDog for details on how he found it.

I had the same problem with my Samsung 220wm LCD monitor. I was about ready to chuck it and decided that I would open it up and take a look - since I had nothing to lose if I destroyed it. I noticed that there was a fried
(exploded and unrecognizable) capacitor on the power board (c523 on a ILPI-055 / E59670 board). The adjacent capacitor (c528) looked similar and had "N3 3KV SEC" written on it. I couldn't find a schematic online for my monitor so I did a search on N3 3KV SEC to find out what the capacitance value is for this type of capacitor.

I got a lot of hits for people having problems with both the c523 and c528 but nobody seemed to know what the capacitance of either is. What I did learn from one capcitor manufaturer's spec page is that "N3" gives the physical
characteristics of the leads of the capacitor (presumably so board designers can know how far apart to drill the holes for the leads and how big the holes need to be). 3KV was obvious 3 kilo volts, and SEC (if I'm reading the chart correctly) means high temperature/low dissapation +/- .25 pF tolerance, etc -- nothing on the actual capacitance.

So then I decided to attack the problem from the board angle. What I found is that the ILPI power boards seem to be used in a lot of different monitors from different manufacturers. So I did a search on ILPI-055 and got nothing but a lot of other issues with various ILPI power boards. I did a search on e59670 and eventually found a schematic for a Viewsonic VX1935wm-3 using what I believe is a ILPI-004 power board.

(http://michaeljaylissner.com/archive...935wm-3_sm.pdf)

On page 66 of the schematic it shows that c523 is a 10pf/3KV capacitor and that c528 is a 3pf/3KV capacitor.

Comparing all the other capacitors on my board with the capacitors listed for this board, it was vary apparent that the ILPI-004 is very similar to my ILPI-055. So I went to Digikey.com and ordered Part # 445-2821-ND (Cer Cap 10pF 3KV 5% radial). I made sure that the temperature ratings were in the 20 to 85 degree C range etc.

Any way, the cap was $0.43 plus $2.00 Shipping and handling and took 2 days to arrive. Once It arrived, I unsoldered the remains of the previous capacitor and did my usual terrible job of soldering in the new one and the monitor seems to be working great for the last 3 weeks now.

Not bad for an amatuer with one year of high school electronics 38 years ago.

 

[Stephen Simons]

What is this capacitor? (the one on the bottom)

Sorry for invading another post, but I can't create a new post for some reason