Dell E153FPB Back Light problem

[dell-usional]

Re: Dell E153FPB Back Light problem - and another

top fix chap, a bit of 2 amp fuse wire done the trick. all hale brian h

[coolcurrent]

Re: Dell E153FPB Back Light problem

Hello, my dell flat screen too has this problem. I have read the entire post, but it seems there ins't any particular solution. Can anybody point out which transistor is causing this

thanks

[PlainBill]

Re: Dell E153FPB Back Light problem

Hello, my dell flat screen too has this problem. I have read the entire post, but it seems there ins't any particular solution. Can anybody point out which transistor is causing this

thanks

1. The problem is not caused by a transistor. The problem is caused by bad solder joints on the transformers.
2. There are two identical circuits for each inverter. Either (or both) transformer can have bad solder joints. Usually only one pair of transistors fail.
3. You need an ohmmeter to determine which transistors are shorted.
4. If you replace the transistors without resoldering the transformers the new transistors will also fail.
5. Several different boards were used in each model of the monitor. Without determining which version you have, it is impossible to give you a location number.
6. There are pictures of some of the different versions of the board in this thread. Since you were unable to identify which one you have, a picture of YOUR monitor will be necessary. See my signature for information on taking and attaching one.

PlainBill

[coolcurrent]

Re: Dell E153FPB Back Light problem

my monitor model is E153FPb. one unique thing about mine is that you have to whop the monitor on the back, then it will come on and work just fine. then after powering off for long hours, the cycle restarts again

[PlainBill]

Re: Dell E153FPB Back Light problem

my monitor model is E153FPb

BFD!!! I had assumed you were smart enough to post in a thread that was related to your monitor. That STILL doesn't tell me what power supply / inverter board Dell happened to use in it!!! It is easy to identify the likely defective parts by looking at the board, I know of no way to do so without opening up the monitor.

PlainBill

[coolcurrent]

Re: Dell E153FPB Back Light problem

BFD!!! I had assumed you were smart enough to post in a thread that was related to your monitor. That STILL doesn't tell me what power supply / inverter board Dell happened to use in it!!! It is easy to identify the likely defective parts by looking at the board, I know of no way to do so without opening up the monitor.

PlainBill

Here is the board picture

[smason]

Re: Dell E153FPB Back Light problem

Here is the board picture

Seems obvious to me, between reading the rest of this thread, the fact that if you whack the monitor it comes on, and from that (not terribly good) picture.

BAD SOLDER JOINTS

[PlainBill]

Re: Dell E153FPB Back Light problem

Here is the board picture

Good grief, couldn't you make it smaller? Fortunately I was able to match it to a real picture.

Large blue circles - transformers with bad solder joints. Remove as much solder as possible from the pins and resolder

Red circles - bipolar transistors (2SC5706 or 5707). Test and replace both if either transistor in a pair is shorted.

Small blue circles - FET transistors, one for each pair of bipolar transistors. Sometimes fail when the bipolar transistors fail. Test and replace if shorted.

Yellow circle. Picofuse. Test and replace if open.

PlainBill

[alexanna]

Re: Dell E153FPB Back Light problem

The2 gray capacitors in the area of PlainBills Red circles are known for poor solder joints also. If you gently wiggle them sometimes you will see the solder move.
Al.

[coolcurrent]

Re: Dell E153FPB Back Light problem

thanks for the fast response, i'll do my homework and give feed back tomorrow.

without a sucker, which method is best for removing components with a soldering iron, i presently use brush with trimmed tips, but the brush seems to go bad quickly after few uses

[coolcurrent]

Re: Dell E153FPB Back Light problem

Good grief, couldn't you make it smaller? Fortunately I was able to match it to a real picture.

Large blue circles - transformers with bad solder joints. Remove as much solder as possible from the pins and resolder

Red circles - bipolar transistors (2SC5706 or 5707). Test and replace both if either transistor in a pair is shorted.

Small blue circles - FET transistors, one for each pair of bipolar transistors. Sometimes fail when the bipolar transistors fail. Test and replace if shorted.

Yellow circle. Picofuse. Test and replace if open.

PlainBill

Hello, thanks i solved the problem by just entirety de-soldering the two transformers you mentioned and re-soldering them again.

i will be watching it for a day or two

thanks

[PlainBill]

Re: Dell E153FPB Back Light problem

Hello, thanks i solved the problem by just entirety de-soldering the two transformers you mentioned and re-soldering them again.

i will be watching it for a day or two

thanks

Cool!!! You might also consider buying a lottery ticket. You might get lucky twice. Not only was the problem easy to fix, but nothing was damaged.

PlainBill

[josh_zedlav]

Re: Dell E153FPB Back Light problem

Hi Folks I'm New here I need help regarding may Dell E153FB.. I've been working on my monitor for almost 3 days.. I tried all i have read from this forum like changing the 4 transistors, resoldering the transformers and other components, and changing the fuse.. It's just that it still keep on turning on and off.. Any possible solution you can give guys? thanks in advance

[Welchs101]

Re: Dell E153FPB Back Light problem

Have you checked the "bulbs"?

If its turning on and then abruptly turning off then you might want to check the bulbs.

[retiredcaps]

Re: Dell E153FPB Back Light problem

It's just that it still keep on turning on and off.

How long does it stay on? 2 seconds? 2 minutes? 2 hours?

[EGuevarae]

Re: Dell E153FPB Back Light problem

Hi Folks I'm New here I need help regarding may Dell E153FB.. I've been working on my monitor for almost 3 days.. I tried all i have read from this forum like changing the 4 transistors, resoldering the transformers and other components, and changing the fuse.. It's just that it still keep on turning on and off.. Any possible solution you can give guys? thanks in advance

Caps?

[josh_zedlav]

Re: Dell E153FPB Back Light problem

hi tnx for the reply.. can you tell what is the proper way of checking the bulbs? another problem i encountered is that I cannot push the button while the lcd is on this mode.. It only took seconds to turn on and off.. then long minutes on then off again

[rukirie]

Re: Dell E153FPB Back Light problem

Hi all,

I just wanted to share my experience:

My father-in-law had a Dell 153FPB that 'died', i.e. had no backlight.
I saw it flash a bit when I plugged it in so I decided to google a bit to see if these things had a common point of failure (usually bad caps in my experience).

Fortunately, I read this forum and that pointed my attention to the PF751 fuse, not very obvious for an amateur like me I must confess.

I measured great resistance over the PF751 fuse, an indication of a blown fuse, so I replaced it with a 2A slowblow fuse and lo and behold!
We have a backlit image again! I hope the new fuse holds.

Thanks for the groundbreaking work,

Eric Benedikz

ps.saw this picture of the culprit:
http://s807.photobucket.com/albums/y...g=Dell+E153FPB

[PlainBill]

Re: Dell E153FPB Back Light problem

Hi all,

I just wanted to share my experience:

My father-in-law had a Dell 153FPB that 'died', i.e. had no backlight.
I saw it flash a bit when I plugged it in so I decided to google a bit to see if these things had a common point of failure (usually bad caps in my experience).

Fortunately, I read this forum and that pointed my attention to the PF751 fuse, not very obvious for an amateur like me I must confess.

I measured great resistance over the PF751 fuse, an indication of a blown fuse, so I replaced it with a 2A slowblow fuse and lo and behold!
We have a backlit image again! I hope the new fuse holds.

Thanks for the groundbreaking work,

Eric Benedikz

ps.saw this picture of the culprit:

Important!!! Resolder all inverter transformers or you will be replacing the fuse again. And some transistors.

For future reference, note the links in my signature on the proper way to attach pictures.

PlainBill

[EGuevarae]

Re: Dell E153FPB Back Light problem

I measured great resistance over the PF751 fuse, an indication of a blown fuse, ...

???