Dell E207WFPc

[PlainBill]

Re: Dell E207WFPc

I tried several of the pins for readings, but my DMM was jumping around so much I could not get a reading. The chip and the 3R3 component are both getting so hot you can't touch them with your finger and the same thing applies to the board even through to the back. Is this a short circuit or a bad component? Is one problem related to the other?

It appears C15 (and possibly others in the area) is the filter for the main output. With power off, measure the resistance across it. With power on, measure the voltage across C15. Try to have the power on as little as possible.

PlainBill

[killian6pk]

Re: Dell E207WFPc

The resistance reading for C15 is 34.6 ohms. I still can't get a DC reading on the caps because the DMM display is bouncing around so much. I think it is because I can't find a ground spot for the black probe. Would that be the problem. With the boards hooked up inside their cage they are not available to use as a grounding point. I have tried every piece of bare metal without any luck. For me to be able to get to the caps etc. on the TCon it must be opened. It's normal position is component side down. on the back of the LCD. Any ideas.

[PlainBill]

Re: Dell E207WFPc

The resistance reading for C15 is 34.6 ohms. I still can't get a DC reading on the caps because the DMM display is bouncing around so much. I think it is because I can't find a ground spot for the black probe. Would that be the problem. With the boards hooked up inside their cage they are not available to use as a grounding point. I have tried every piece of bare metal without any luck. For me to be able to get to the caps etc. on the TCon it must be opened. It's normal position is component side down. on the back of the LCD. Any ideas.

I'll try to be more explicit. I wanted you to measure the voltage across the cap - one probe on each end. At this point I would say it is a moot point. A 34.6 ohm load is significantly above the rated current, and is most likely the cause of the problem.

At this point I'd suggest measuring the resistance across each cap that measured in about the same range and remove the one that reads lowest. If you are lucky you will get it on the first try. If none are shorted, keep looking.

PlainBill

[killian6pk]

Re: Dell E207WFPc

Thanks Bill, Sorry I am so thick headed. I tried measuring the voltage with both probes on the same cap and I am still not getting a readable number because the DMM display is bouncing around so much. I will do what you suggest and go one by one. Once i find a cap like you are describing how do I determine its value. I am guessing that these are smd ceramic caps and from what I have been reading there are no codes to determine UF or PF etc. If they are shorted will I get a useable capacitance with say my ESR meter?

[PlainBill]

Re: Dell E207WFPc

Thanks Bill, Sorry I am so thick headed. I tried measuring the voltage with both probes on the same cap and I am still not getting a readable number because the DMM display is bouncing around so much. I will do what you suggest and go one by one. Once i find a cap like you are describing how do I determine its value. I am guessing that these are smd ceramic caps and from what I have been reading there are no codes to determine UF or PF etc. If they are shorted will I get a useable capacitance with say my ESR meter?

You aren't going to get any meaningful information from the shorted cap with any kind of meter, however if there are any more on the same power rail with the same physical dimensions you can measure the capacitance of them. I would expect something over 1 uF, probably as high as 15uF.

PlainBill