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I cannot find the information on what this SMD Aluminum Electrolytic Capacitor is

post #1 of 21
Thread Starter 
This SMD Cap goes on a Mitsubishi DLP 73735 Main board. Allow me to describe it. on top there are number and letter codes..They do not match with what I've been able to look up on deciphering them. Reading from top to bottom...There is an 'O' looking symbol, then under that, there is a 'P2', then under that there is '680A', and finally under that there is a 'UD'. What is this so that I can order it online? I believe the P2 stands for .2 Picofarads.....680A might stand for 68pf, at 10V, or possibly 1% Variance of temperature....no idea what the UD is, or the 'O' symbol at the top.

Thank you for your time!

post #2 of 21
A close-up picture would help...
post #3 of 21
Thread Starter 
Here, I took two. Couldn't get all of the numbers at once to show. Notice how the 'X' in the top cap seems to bulge out a little? It is actually bulged in reverse of what the 'score' is on the cap, though the top of the actual cap does not look that bulged. PS works fine. The power comes in from the PS through here first into the main board, but just disappears at this spot on the board...thinking it MUST be these three caps....I hope....but, I can't figure out what they are in order to purchase them online Would you also agree with my logic on this being the issue? There is NO power to the rest of the TV...no fans on, no lights on the front, can't access the error message light codes for the power light on the front...absolutely nothing works...New PS, reset switch works, relay on PS clicks when plugged in...though Power button on the front of the TV does not work (it's tied into the Main board I believe). ALL circuits funnel electricity from this one spot at the beginning of the main board where power comes into it....all Surface mounted fuses show continuity too. The only odd thing I could find anywhere else on the TV is a diode on the PS, between the board, and ground, that I cannot get a reading with my Fluke of any kind through. It's one of those glass bubble kind, with the black spring, or carbon looking thing in the middle. It looks a little misshapen, and appears to have sort of melted into the glass, but it isn't burnt at all, nor does it look blown...not sure what that is, and the local large electronics supplier basically refused to help me do anything towards replacing it, looking it up so that I could order another, or giving me any sort of opinion. What jerks...they lost my business forever... anyway, I'll move onto that being the cause after replacing these caps, maybe bypass it by making a jumper to see if anything turns on...but like I said, brand new PS from the factory...that shouldn't be the issue, and it doesn't make sense that it would be.

Thank you for your help.

post #4 of 21
Thread Starter 
Working on it. Pictures are being held by the moderator...
post #5 of 21
Did you look here?

And here?
Edited by WS65711 - 2/19/13 at 7:43am
post #6 of 21
Thread Starter 
AH, Awesome! I was looking online for that a few days back, but could not locate the specific model I have. Let me go through it and see. I'm sure it will be listed.

Thank you so very much!
post #7 of 21
Thread Starter 
Alright, cannot find that cap ANYWHERE online, and there is no replacement. Correct me if I am wrong, but if you have a 680p, 10V cap, you can go up in voltage, as long as you stay with the same farans, right? And to clarify for myself so that I don't screw this up, a 680p is the same as a 68uf...correct? I can find replacements for it if this information is correct...

Thank you, btw, for the link to the the forum post about my issue. I had not seen that one, though I searched long and hard, and it is exactly the problem. You are so VERY helpful!

Have a Blessed day!

post #8 of 21
680pf = 0.68nf = 0.00068uf Link

Yes the voltage rating can be increased (higher than 10 volts)

Did you find that cap on the schematics?

I believe the "680" may indicate that the value is 68pf. Link Link

This may be the part you need (but I'm not sure if really available)
Edited by WS65711 - 2/19/13 at 12:09pm
post #9 of 21
Anything in a tin can is likely to be an electrolytic cap. There is a possibility that it is tantalum, but much less likely. Electrolytic caps are usually used where large cap values are required 10 uF and up.
Usually one can get away with using a capacitor of larger voltage rating and larger value, but this in not always the case. In a computer most capacitors are bypass capacitors, there just to keep the voltage stable under wildly changing load conditions. These are the ones that one can substitute a larger value & larger voltage.
If the cap is used in an audio filter, changing the value would change the frequency response, a bad idea.
In some power supply designs, the equivalent series resistance must be within a range to keep the power supply stable. If one gets the equivalent series resistance too high or too low, the power supply will oscillate. This would be very bad.
It is best if you can get an exact replacement unless you know how the capacitor is being used.
post #10 of 21
I believe the capacitors are ID'd as C9G50, C9G51, & C9G52 in the schematic in the service manual I linked to in a post above. If you open the service manual and search those item numbers in Acrobat it will show you where they are in the circuit . . .
post #11 of 21
Looks to me like an electrolytic capacitor. Looking at the schematic and parts list, could be either capacitor c9g50, c9g51, or c9g52 -- all Mitsubishi 189P256060 C-al-elec (10V 680) 'G' -- that is, an smd electrolytic 10V (DC) 680uf (microfarad) capacitor. Don't jump things out... could very easily blow something else out in doing so. Replace defective parts with exact or equivalent parts. I also see several fuses on the Main Board schematic in the 12V to 5V, and 12V to 3.3V converters, too. Check the voltages at the test points for them to rule out open fuses.

post #12 of 21
Thread Starter 
Yeah, I was thinking the 680 meant meant 68pf too. However, there was a link somewhere I saw that used the capacitor code 681 for that cap, which goes on a 680pf, not a 68pf...left confused by that.. still need to look at a few more links about all of this...but my brain is melting now I think..

Found the cap on the schematics...many thanks. It is part number 189P256060, and does not exist anymore. Here is the 'description' from a seller of it - C-al-elec (10V 680) 'G'...(http://www.encompassparts.com/item/7670237/Mitsubishi/189P256060/C-al-elec_%2810V_680%29_G), but they don't have it either. I guess the (G) is the variance? I think that means 2%, if that is indeed what that G means in this instance. There are no known exact replacement parts for this. But...I was thinking...Is there any way, with the variance of these caps being 2%, that I can take a normal cap, and use it instead? I have seen the discussions about the ESR Values, but wasn't sure if this would play too much of a role in where these caps are going. Though I am not positive about their exact role in this main board, they do appear to be funneled down through other components into proper voltages for further 'down the line'. Is it possible the power fluctuations within a normal cap would be leveled out, if I switched one of these SMD caps for a different kind? Maybe a radial one? And, if a radial type is used instead, using one with more Voltage...which in some information lowers the ESR value....and is also one I can actually locate?
Edited by DPenhead - 2/19/13 at 2:10pm
post #13 of 21
Thread Starter 
Fuses are not blown. Looked at all of those already for continuity, and they check out.
post #14 of 21
I believe they're filter caps -- on the output side of a DC/DC converter, they help smooth any AC ripple that may exist.

As for parts sourcing, search for Aluminum Electrolytic SMD 680uf 10V (in Mouser or DigiKey, for example) -- should come up with lots to choose from for less than $1 each (plus shipping, of course.)

Have you measured for resistance directly across the caps (without voltage applied)? If they're shorted, they could be your culprit.

Or, when the board is energized (power applied to it), If you read voltage across the capacitors they're not likely the problem. Measure between TP1.2VS and ground, you'd have 1.2VDC -- that would mean C9G50 is likely good, or open. Between TP5VSL and ground, you'd have 5VDC and C9G52 is likely good, or open. And betweenTP3.3VS and ground, you'd have 3.3VDC with C9G51 being good or open. Always take care when working on live circuits.

Also take care when removing/replacing smd's. An smd rework station is nice to have, but if you're very careful soldering you can remove and replace them without damaging the circuit traces/board.

Re: the misshapen diode -- if it got hot enough to melt glass, the diode would've blown long before that. And if it didn't, the circuit traces would've let the magic smoke out.
Edited by netsurfer44 - 2/19/13 at 2:29pm
post #15 of 21
Thread Starter 
One of the caps in this group has conductivity across it, and reads no capacitance that I could determine. I do know though that that can happen sometimes with the power off. The others seem to read in the ballpark of alright, but all appear a bit bulged in the score of the 'X'...like the X is flipped inside out. Doesn't really look right, though not anywhere near as bad as some others I have seen that were obvious. Hopefully any damage that may have originated from the Power Supply stopped with whatever happened to these capacitors on the main board...Figured I'd start with replacing them, and just see where that takes me... I have not run a check on them with the power on...little nervous about doing that and really messing something up. Probably aught to charge them up with the power on, then check them in sequence to see how fast they leak...repeatedly over a few minutes...Think I did that though...don't remember, but I can check again.
post #16 of 21
Thread Starter 
Well, here's the problem I have been running into. On the end of the description for this part it says (G). This IS the tolerance code right? If so, that code is 2%...however, every single smd I have come across is an 'M' tolerance code, or 20%.

Edit - OR, does this 'G' designate some other aspect of the SMD cap? Just found another 'M' cap with a G designation for what I think is the way the internal circuitry is laid out inside the cap. Is this instead what the 'G' means?
Edited by DPenhead - 2/24/13 at 7:36am
post #17 of 21
what I think is the way the internal circuitry is laid out inside the cap.

A capacitor is two conductive plates separated by an insulator.

Electrolytic caps have a very wide tolerance range, up to 150%. I would not expect to see one with a 2% tolerance.
These are filter caps, so their actual value isn't really important.
post #18 of 21
Thread Starter 
Alright. Thank you for your insight.
post #19 of 21
It's a 68 uF, 10V aluminum electrolytic. 20% is good enough, it's just a filter cap in this circuit.

Digikey offers multiple ones starting at about 70 cents, depending on the physical dimensions.
post #20 of 21
Thread Starter 
Ordering parts, but they're going to arrive after I leave home on the road. Might be a month before I get to fix it. Have to work out of town. I'll repost when I get back as to if it fixed it, or if I have further questions.

Thank you. I always learn something new when I'm on here. You people are very helpful...
post #21 of 21
Originally Posted by DPenhead View Post

.... I'll repost when I get back . . .

Don't you forget.. or we'll come lookin' for you . . . eek.gifbiggrin.gif
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