Dell E172fpb

[doorynrun]

Re: Dell E172fpb

Hello All,
I'm new to this forum. I joined a couple of weeks ago to better understand what it might take to repair a Dell e172fpb I'm trying to save from the landfill.

It started out as a 2 Seconds To Black problem that was traced to a couple of '5707s being shorted. After getting a transistor/fet/fuse repair kit from eBay it then started doing the Power Light Flashing mode, so I got a replacement cap kit from eBay. Really there was only one obvious cap failure, one of the 1000mf @ 10V ones...but what the heck put them all in.

I've finally discovered the true nature of the problem: a bad CCFL. It took a while, but I noticed arching along the edge of the LCD panel. After disassembling the panel I could see a burn marks at the end one of the tubes.

It looks like CCFL-Warehouse has the lamp assemblies for $35 or so. I haven't decided yet to put out the cash. It's really not worth it, but the inverter and digital boards are in good shape. Is there any interest in anyone buying these boards?
--Cheers!

[cadillacman]

Re: Dell E172fpb

Ugh. nevermind. Stepped out of my car tonight after work, monitor disassembled in a bag. Shit the car door, prosseded to slip and slide all over some nasty slick ice, and broke the heck out of the lcd. Ugh.

Oh well. At least i have parts for the next one i suppose.

[cadillacman]

Re: Dell E172fpb

hmm.. looks like im measuring 140ohms across the center and third leg of the little "2sc" transistors everyone is talking about. Time to pull them and see if i have an odd man out. Im hoping i have one shorted compared to the rest, at least i will know thats what it is. A repair kit on feebay for only like $8 so , if i find my odd duck out i will order that kit. The caps visual check ok but i know that doesent mean mean much.

[cadillacman]

Re: Dell E172fpb

I just got one of these. Unlike most of you fellows, mine is doing thr 1 second to black issue.

If i shine a light at the screen, i can still see the image, and the green power led stays on solid so the monitor is staying on except for the backlight.

Should i tear it down and check these common suspect transistors anyways?

edit whoops this is a E173FPc maybe its not the same internally.

[veeone]

Re: Dell E172fpb

How do i identify this part as it is now making a squealing noise and not all the time. It is T601 on the power board number on the sticker is 19.20267.001
Photo attached.
Cheers

Monitor has been plodding on for months and have been waiting for something to give up but not the case. Just squeals like a pig once it starts to get warm so good for about 20min and then it starts it call!!
So today replaced the large black main cap in the photo the 450V 100mfd Elite branded with a japanese equivalent and did not make any difference.
Now to locate a tranformer in the photo if i can as thats were the noise is coming from for sure!! Anyone have any idea where i may get one?? Cheers Vee

[Rtech]

Re: Dell E172fpb

Meter reads at the socket fluctuates between 241-245v ac. I might just get a new cap and see if i get different readings would that be a good idea? Cheers Vee

Must be worh a try.keep the Forum informed please, as this is odd !!

[veeone]

Re: Dell E172fpb

Meter reads at the socket fluctuates between 241-245v ac. I might just get a new cap and see if i get different readings would that be a good idea? Cheers Vee

[Rtech]

Re: Dell E172fpb

Well obviously something is amiss,BUT trying to identify what,is not going to be easy.The DC input seems correct to give you the correct DC voltage on the cap.The first thing to do, although it may seem odd,is to measure the AC in the wall socket...we know its going to be about your 240v mains AC,BUT what does the meter actally read,on the AC range you used to measure on the Cap ??/

[veeone]

Re: Dell E172fpb

I tested each 3-4 times with same results as i wanted to be sure i got it correct.
Why would it say that?

[Rtech]

Re: Dell E172fpb

730V AC !!!!!!! measure again I suggest....

[veeone]

Re: Dell E172fpb

Well soldered on some extensions to the cap. We are 240v system in Australia

Its an Elite brand Cap 450WV 100MFD pc(m) 105c

Readings 331v DC
730v AC

[veeone]

Re: Dell E172fpb

Ok thanks will try that later and get back to you. Cheers Vee

[budm]

Re: Dell E172fpb

You can solder two wires to the leg of the cap and run them out to allow you to connect the probes to them, you MUST BE REAL CAREFUL! you are working in the LINE (HOT side) of the circuits. Do not touch any thing with your hands.

[veeone]

Re: Dell E172fpb

With this monitor its pretty hard to do as you cannot get to the otherside of the board but will give it a try. Must be a workaround.
Also noise is definatley emanating from the transformer i rolled up a sheet of paper and put the tube over it and you can hear the noise easy and nothing when i do the same to the large cap. Cheers Vee

[budm]

Re: Dell E172fpb

That squealing noise may be due to bad main DC filter cap (that large black cap in the primary side). Put the meter in AC mode and take the voltage reading on the two legs of the cap, also take the DC reading as well.

[veeone]

Re: Dell E172fpb

How do i identify this part as it is now making a squealing noise and not all the time. It is T601 on the power board number on the sticker is 19.20267.001
Photo attached.
Cheers

[veeone]

Re: Dell E172fpb

Replaced the large brown 35v 1000uf with units about 50% larger in size (just squeezed in) and the rest of the caps for the board are on order.
Fired it up anyway as will be a several days for stock to come in and it is working well. Yay
Will replace the others so i know i have all good quality caps and the board has been totally resoldered all over so hopefully no more problems. Thanks for all advice everyone and tutorials retiredcaps . Vee

[veeone]

Re: Dell E172fpb

This Cap seems to be the probable issue so will get some in town tomorrow and replace it and others and see if i get a result.
Sorry macro on my camera is not that good but the large brown 35v 1000uf is the bulging one.
Missed it before when i replaced at the mofsets etc. Vee

[veeone]

Re: Dell E172fpb

Ok did i get i correct? Vee

[retiredcaps]

Re: Dell E172fpb

As i'm new to electronics which is the startup cap?

http://s1063.photobucket.com/albums/...rent=DV172.jpg

Post your images following my sig file exactly.