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Old 07-08-2009, 02:22 AM   #21
Bobdee
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Default Re: Dell E153FPB Back Light problem

Quote:
Originally Posted by Bubii
Hi Guys! I own Dell E153FPB and it has backlight problem. It works for a few secs and than the backlights turn off. The pictuire is there but no backlight. I did change pf751 and resoldered the transformers' contacts and it worked for about 20 mins (I tought it was fixed) and now it is just the same. I know it's easier to trow it in a trash but I spent so much time on research on this s##t...It was said that the problem might be the SG6841S High-integrated Green-mode PWM Controller but before I buy it I wanna know what you suggest. Help...Help...Plz.
Thanks.
Check out the 4 transistors on Inverter = Q739, Q740, Q759, Q760
You are looking for shorts between the pins, if they check out okay then check there solder joints to board of the transistors with about a 10X magnifying glass looking for ring crack or any bad solder joint to resolder
Do the same to the 2 mosfets as well Q743, Q759
also check the rest of the board for ring cracks or bad solder joints, Benq boards always have bad solder joints
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Old 07-08-2009, 02:39 AM   #22
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Default Re: Dell E153FPB Back Light problem

Mr Brianh...... i ask how thin is the wire you jumpered in replace with the MS 2A? or what other devices i can replace with that device? can i replace it ordinary fuse?with 2A on its spec?
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Old 08-22-2009, 09:46 AM   #23
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Default Re: Dell E153FPB Back Light problem

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Originally Posted by Nama
Yet another PF751 bad. Monitor has been on now for 3 hours with no problem. Thank you for you follow up Brianh. Jacob

Where can these Mini Pico Fuses be purchased?
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Old 08-22-2009, 01:44 PM   #24
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Default Re: Dell E153FPB Back Light problem

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Originally Posted by freakytiki4u
Where can these Mini Pico Fuses be purchased?
Mouser, Digikey both carry them.

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Old 08-22-2009, 01:50 PM   #25
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Default Re: Dell E153FPB Back Light problem

Wow, very fast reply from a few of you. I like this forum! Thank you very much. I actually just got off the phone with Digikey and have ordered what I need. Ill post if it works when I receive the parts. You guys rawk! I repair computers for a living and dable in electronics repair so if you ever need anything just ask.
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Old 08-26-2009, 11:00 AM   #26
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Default Re: Dell E153FPB Back Light problem

Update.......I ordered the wrong type of fuse . What I ordered were not axial (no legs) they were just square as if they were meant to be popped in. They were the correct voltage and amperage so I decided to solder some legs on and put it in. It works perfectly! I have thrown out sooooo many flat panels with bad inverters that I most likely could have fixed /sigh
Thank you guys so much for this thread.
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Old 09-08-2009, 11:58 AM   #27
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Default Re: Dell E153FPB Back Light problem

The Flat Panel I fixed has stopped working again. Now it just blinks on and off. Any ideas anyone? I was so excited to have it working.
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Old 09-08-2009, 08:41 PM   #28
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Default Re: Dell E153FPB Back Light problem

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Originally Posted by freakytiki4u
The Flat Panel I fixed has stopped working again. Now it just blinks on and off. Any ideas anyone? I was so excited to have it working.
What did you replace in the unit (and with what)?
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Old 09-12-2009, 07:09 AM   #29
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Default Re: Dell E153FPB Back Light problem

I replaced the PF751 Pico Fuse and the monitor worked for a solid week. Now it just blinks on and off repeatedly.
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Old 09-12-2009, 10:21 AM   #30
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Default Re: Dell E153FPB Back Light problem

I justy replaced the Pico Fuse again and its working again. What would cause the Pico Fuse to keep burning out? Please be very descriptive about location and part description as Im just a beginner board level repair newbie.
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Old 09-12-2009, 10:39 AM   #31
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Default Re: Dell E153FPB Back Light problem

Quote:
Originally Posted by freakytiki4u
I justy replaced the Pico Fuse again and its working again. What would cause the Pico Fuse to keep burning out? Please be very descriptive about location and part description as Im just a beginner board level repair newbie.
Probably a leaky transistor. Provide GOOD pictures of the inverter board and we can identify twhat to test.

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Old 09-12-2009, 11:11 AM   #32
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Default Re: Dell E153FPB Back Light problem

ok will do, the picture is attached of the Inverter Board.
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File Type: jpg PS-dell-sm.jpg (415.5 KB, 211 views)
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Old 09-12-2009, 03:12 PM   #33
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Default Re: Dell E153FPB Back Light problem

Quote:
Originally Posted by freakytiki4u
ok will do, the picture is attached of the Inverter Board.
Great picture!! I've marked it up. The four transistors circled in red should be checked with an ohmmeter. We are looking for differences between one pair and the other.

Also, two transformers were circled in blue. Resolder the leads on all of them.

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Old 09-12-2009, 04:53 PM   #34
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Default Re: Dell E153FPB Back Light problem

Thank you very much for the quick reply. I will resolder and check with Ohm Meter tomorrow.
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Old 09-22-2009, 08:04 AM   #35
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Default Re: Dell E153FPB Back Light problem

Quote:
Originally Posted by freakytiki4u
Thank you very much for the quick reply. I will resolder and check with Ohm Meter tomorrow.

If I want to order the 4 transistors on Inverter = Q739, Q740, Q759, Q760
for replacement, what would I ask for?
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Old 09-22-2009, 08:26 AM   #36
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Default Re: Dell E153FPB Back Light problem

Quote:
Originally Posted by freakytiki4u
If I want to order the 4 transistors on Inverter = Q739, Q740, Q759, Q760
for replacement, what would I ask for?
They are either C5707s or 6s
Read the front of one, (you may need magnifying glass)
You can replace 7s with 6s if doing all four, but there are plenty of both on ebay (type in search box 2SC5607)
You can get kits with 4 transistors + 2 fets fu9024n and a 2 or 3 amp p/fuse
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Old 09-22-2009, 08:37 AM   #37
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Default Re: Dell E153FPB Back Light problem

Quote:
Originally Posted by Bobdee
They are either C5707s or 6s
Read the front of one, (you may need magnifying glass)
You can replace 7s with 6s if doing all four, but there are plenty of both on ebay (type in search box 2SC5607)
You can get kits with 4 transistors + 2 fets fu9024n and a 2 or 3 amp p/fuse

Thank you very much, I found the kits on Ebay and have a few on the way. I appreciate the continued quick replies. You guys really do rock!
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Old 09-22-2009, 04:04 PM   #38
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Default Re: Dell E153FPB Back Light problem

Quote:
Originally Posted by freakytiki4u
Thank you very much, I found the kits on Ebay and have a few on the way. I appreciate the continued quick replies. You guys really do rock!
Just remember to resolder transformer points and all other cold solder areas that you come across, or either the 07's will fry again ...
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Old 09-22-2009, 04:07 PM   #39
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Default Re: Dell E153FPB Back Light problem

Quote:
Originally Posted by eguevarae
Just remember to resolder transformer points and all other cold solder areas that you come across, or either the 07's will fry again ...

Will do and thank you for the info
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Old 09-23-2009, 09:55 AM   #40
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Default Re: Dell E153FPB Back Light problem

What is the proper way to test the Transistors? I noticed they have 3 legs each. I tested with my Ohm meter and there are differences but I would like to know specifically what Im looking for and how to properly test to determine defective ones.
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