Common Fault In Dell E151FPb 15″ LCD Monitor
I have repaired many Dell E151FPb 15″ LCD Monitor. The complaint was no power (LED no light) and when you test the secondary output voltage with your analog meter, you could see that the voltages are actually pulsating! This is a common problem and i have repaired many of them. The cause of the problem is not a bad filter capacitor, faulty power IC, defective resistor or even diode. It was actually due to 2n7000 FET that was breaking down when under full load! That means the FET tested okay with your meter but fail when under full operating voltage.
I still could recall the first time i troubleshoot this problem. It took me many hours to solve it and now this problem can be solved in a matter of seconds! It is good to write down in a book all the problems and solutions in electronic repair so that you will not waste your precious time recalling the solutions.
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Scott
December 15, 2008 at 8:34 am
Hi, read your article on the Dell E151FPb monitor, I have one and was wondering if you could help me.
The screen was flickering and going white sometimes, so I took the main board out and looked, there were a few dry joints which I re soldered.
When I turned it on, the flickering was reduced but it still did flicker.
Took it apart again and rechecked, touched up a few more joints and turned it on, the Dell logo came up then flickered went white and turned
itself off.
When I turn it on now there is a high pitch whistling noise, the screen is white, sometimes with coloured lines up and down the right side, stays like this for a few seconds, then turns itself on and off every couple of seconds.
There doesn't seem to be any more bad joints, Ive rechecked all my soldering and cant see any obvious problems.
Do you think this is the 2n7000? I cant find any open or shorted diodes or resistors.
All I have is a multimeter and a soldering iron, I don't like poking around measuring while it is on, do you think it is an easy fix :)?
Scott.
admin
December 16, 2008 at 8:36 pm
Hi Scott,
If all the output voltages are okay then chances the problem in the LCD panel. I had came across few that have white display and it turned out to be a bad lcd panel.
Jestine
Scott
December 18, 2008 at 11:21 am
Hey Jestine,
Thanks for replying, would you be able to tell me where I should measure and what the voltages should be?
Thanks.
admin
December 24, 2008 at 6:32 pm
Hi Scott,
You should measure it at the mainboard (vcc supply voltages to ICs) and expect few voltages like 1.8 v, 2.5 v, 3.3 v and 5 volts!
Jestine
Scott
January 3, 2009 at 8:26 am
Jestine,
I measured the voltages from the power board to the smaller board at the pins
and got:
0.87v
2.65v
3.33v
3.33v
3 pins had 0v on them and I didn't get 5v, I'm wondering if there is a power supply problem or if its the screen.
admin
January 3, 2009 at 10:49 pm
Hi Scott,
Some LCD model may not have the 5 volt. Check the 3.3 volt and make sure it reach to the lcd controller ic in the lcd controller board. Sometimes there may have one small smd fuse. Make sure it is good. Without voltage to the lcd controller ic means the ic will not work thus you could only see white display. If there is voltage input then i guess you may have to replace the lcd panel.
Jestine
JETTTT
March 31, 2009 at 2:20 am
Hi jestine, I read your article about "How To Repair Dell E152Fpb LCD Monitor With No Display Symptom" in another site, and help me so much troubleshooting this problem in this model of lcd monitor, how your said in the articicle, replacing the 2 amp fuse, the monitor come back to work again. But sometimes in some monitors the fuse break it again.
Why the fuse break?? what need to replace too?
Thanks, and i hope u can help me
JETTTT
admin
March 31, 2009 at 10:55 pm
Hi Jettt,
If the fuse had break again, suspect something that had shorted in the downstream circuit like a shorted p-channel transistor or the push pull transistor. Check on all the semiconductors especially the one in the inverter board.
Jestine
JETTTT
April 1, 2009 at 12:04 am
Thanks Jestine, i will take a look in all the semiconductors..
JETTTT
Brant Meredith
April 16, 2009 at 3:51 am
Hi,
I have three Dell LCD monitors, an E152FPb, an E172FPb and an E173FPb. They are all doing the same thing. When you turn them on the LED shows green for about a second and then turns off and back on over and over. Nothing shows on the screen. Sometimes the 15" will come on after it has been plugged up for a while.
Is this the FET problem you were talking about, and if so how can I repair it. What compoent(s) do I replace?
admin
April 17, 2009 at 9:03 am
Hi Brant,
It could be the inverter board faulty (bad transistors, capacitors, dry joints in high voltage transformer and etc). Sometimes it could be a bad backlight that had caused the display to shutdown. Try check on the backlight first before concentrate on the inverter board. Since you have few models it is easy for you to compare the backlights whether it is good or bad.
Jestine
Craig
June 3, 2010 at 7:26 pm
Jestine, Hello
I have a blown fuse issue on this model. I replaced it and it popped right away. The main Cap 68uf 400v looks alright and I do not see any components that look burned. although I do plan on replacing two 1000uF 16V caps (C707 & C703) along with the big one (68uf) I was thinking of replacing the Mosfet Q601 SSS6N60A, But I have not been able to find one or a direct replacement, is there another manufacture other than Samsung? Every time I try to cross reference, I come up empty> Thanks in advance
Craig
admin
June 3, 2010 at 8:02 pm
HI Craig,
If the FET confirm bad then you can use 2sk2645 as replacement. By the way, if the power fet have problem, generally the power IC may give way too. You need to check all corresponding components in the primary circuit.
Jestine
Craig
June 4, 2010 at 2:29 am
Thank you, I was able to locate part.
ordered the IC601 UC3842B IC and the D604 1N4148 diode.
I found the bridge rectifier shorted as well, but not find original, so went with 200 volt higher rating @ 800V 2 amp p/n: 2KBP06M
All other parts check good
You are a wonderful resource, I thank you again Jestine
Best regards,
Craig
admin
June 4, 2010 at 8:53 am
HI Craig,
You are welcome!
Jestine
Craig
June 8, 2010 at 6:39 pm
Hello Jestine,
Happy to report components suggested were replaced and working as new again.
THANK YOU
Small Question,
Problem with SCEPTRE X9g-Komodo where a verticle band made from inch and one half horizontal lines go from top to bottom, in center of screen. Problem is only seen with white background. I check cable & connectors, but no change, Video card? or poor supply voltage, I hope not LCD panel..
Best regards,
Craig
admin
June 8, 2010 at 10:46 pm
Hi Craig,
Yes it can be the panel.
Jestine
Craig
June 8, 2010 at 11:04 pm
Not giving up yet, will report back I let you know results
Thanks
Chris Lamb
August 2, 2010 at 9:20 am
Please, typically what output voltages does a typical DELL lcd power board output?
12v? 5V? 3.3v?
Many Thanks, Chris
admin
August 3, 2010 at 8:53 am
Hi Chris,
There are many Dell models and 12v, 5v, 3.3v, 2.5v are typical voltages.
Jestine
george aknin
October 21, 2010 at 3:39 pm
I have a MECHANICAL (vs electronics) problem with my E152FPb Dell color monitor. The screen does tilt when pushed backwards from the bottom of the case. The screen does not tilt when pushed backwards from the top of the case. Isn't it suppose to tilt 4 degrees of an angle when pushed from bottom and 21 degrees when pushed from the top?
I thank you in advance for your help.
admin
October 21, 2010 at 10:58 pm
Hi George,
I did not check on the degrees how the screen should be placed. Usually if i secured the screws internally the display will not tilt. I wish that now i have the set with me so that i could give you a better answer.
Jestine
Genaro
January 31, 2011 at 1:44 am
Hey Jestine, thank you so very much for this information. I repaired my DELL E151FPb 15″ LCD Monitomonitor that was flashing a black screen every second or so. I replaced the 2n7000 FET.
Right after I repaired the monitor and plugged it into an electric socket the screen was still doing the annoying behavior but after several more seconds it started to display normally.
Thank you and God bless.
admin
January 31, 2011 at 4:31 am
Hi Genaro,
Good to hear that!
Jestine
Joey
February 7, 2011 at 8:05 am
Hello,
I have a Dell E173FPb monitor that is doing some strange stuff. When you turn it on, the screen is bright and divided into 4 horizontal sections, with the top section being the brightest, and getting darker with each section below it. The bottom two sections have a series of horizontal black lines running through them, with a shaded area that travels back and forth on these lines. The screen gets progressively darker to a point then stops fading. After about 5 minutes, the screen will go black, and the self-test color bars will appear. But then the colors start to change in the color bars. The screen then gets real bright and blotches of greens and purples start "soaking" the screen- it kinda reminds me of the cover to a Saw video. Then it all fades to black. This whole process takes close to 10 minutes, the power light stays green, and it doesn't care if the cord is hooked up or not (it never shows input from the PC). Any ideas?
admin
February 7, 2011 at 10:06 pm
HI Joey,
If the output from the power supply are good and stable then most likely the lcd panel is the fault. Make sure also the connection cable between the mainboard and the lcd panel are secured.
Jestine
Dave
February 26, 2011 at 3:43 pm
I have the SAME DELL. It will power on for a split second, then goes blank. The power light also then would go out. I want to replace the 2n700 and the power transistor. HOWEVER i encountered a problem...I can't find a cross reference to the DELL 334 or P7NC707FP.
Also do you know of a GOOD cross reference source for transistors? I have the NTE cross reference but that seems pretty useless.
I would GREATLY appreciate ANY help you have,
Thanks,
Dave
admin
February 28, 2011 at 4:20 am
HI Dave,
Sorry i do not have the data too. Usually i will use 2sk2645 as a replacement for this power fet.
Jestine
jojogreg
April 2, 2011 at 3:21 am
hi jestine,
I have a problem with my Dell E151FPb 15″ LCD Monitor,When i plug-in the power cord to the ac outlet the power green led automatically start blinking & blinking and never stop.Can you pls. help me solve the this problem?
thanks,
jojo g.
admin
April 2, 2011 at 4:55 am
HI Jojogreg,
It could be something shorted in the inverter board. If the output voltages from power supply is good then suspect a bad Mainboard.
Jestine
Jess Betchaida
June 9, 2011 at 9:31 am
Hi Jestine,
I have a problem with my Dell E151FPb LCD. After connecting, it will display nice but after sometime it will display the CONTRAST going to ZERO automatically, so no more display. Please help.
Thanks,
Jess
admin
June 9, 2011 at 8:32 pm
Hi Jess,
You mean it pop up the menu by itself and the contrast setting automatic move and making the display dim?
Jestine
Trevor
October 3, 2011 at 6:39 pm
Hi,
I have a dell pc monitor, but everything is in reverse. Switch on a white screen appears. The arrow is black not white. when looking up anything it is like looking at an old fashion negative.
Have you come across this before
admin
October 4, 2011 at 2:06 am
Hi Trevor,
Your case could be negative picture.If the output voltages and cables check to be good then suspect a bad lcd panel.
Jestine
Jerry Rose
October 18, 2011 at 9:57 pm
Dell E151FPB
When not connected to computer self test is fine as soon as it is connected to computer goes to sleep mode. If you disconnect from computer it goes to self test.
any suggestions?
I have your lcd monitor repair and have had a fair amount of luck repairing monitors.
admin
October 19, 2011 at 5:50 am
HI Jerry,
Thanks for the support on my ebook. Try this link:
http://www.electronicrepairguide.com/troubleshooting-lcd-tv.html
Jestine
Sunny
November 12, 2011 at 11:11 pm
Hey Jestine, found your blog quite interesting!
I have a problem with my E151FPb moniter, it's button function seem to appear on their own (The moniter's menu opens up without me even pressing it!), this got a bit annoying, I put a OSD lock on it, mainly because it shows a smaller icon than the normal huge menu... but now the lock sign keeps showing up and is smack bang in the middle of my screen, I have no idea what the problem is and I quite really use an expert's advice! I have tried to take the OSD lock off but the buttons dont seem to be working now? :S
Your advice will be much appreciated"
Thanks,
-Sunny
admin
November 14, 2011 at 11:57 am
HI Sunny,
The problem seems to be a bad/corrupted MCU or eeprom ic.
Jestine
Charles
January 12, 2012 at 3:56 am
Hello Jestine-
I am having a variation of the problems discussed here. I have the DELL E151FPb monitor, and not long ago began experiencing what appears to be a common problem (internet search reveals numerous complaint posts by users of this model).
At first, I had the typical problem described; that is, upon powering up the PC/monitor, the monitor would appear to be operating normally, but then the screen would go black, followed by a faint flashing across the screen, along with the green power light flashing on and off, repeatedly. As other users have described, I initially had some success getting the monitor to correct itself, usually by tapping lightly on the back of the monitor housing. After several tries, and once the monitor was able to stay on for some time, it would usually operate normally until powered down. If allowed to idle into screensaver or sleep mode, reactivating the monitor would usually trigger the same problem, thus requiring more tapping, etc. This worked for awhile, but progressively worsened to the point that I decided I would have to open up the unit and search for the problem.
[Note: I am a novice at electronic work and have only an elementary understanding of electronic repair and terminology.]
Upon first examination, all of the boards seem to be in fine condition. No obvious signs of blown components. Diodes and resistors all look good, no apparent bulging or burning. Solder joints appear fine. I don't see any that look suspect, dry, or loose. I poked around a few to make sure, but all seem to be solid joints.
The interesting thing is, after reconnecting the boards and supplying power, somehow the above-described problem had suddenly changed, suggesting that my tinkering around affected the problem in some way. Now, the monitor will power on, the power light illuminates solid and stays on with no blinking. The LCD screen will power on normally, and for a moment, displays normally...it will fully display either the self test graphic or the Windows boot up screen, if connected to the PC. The problem is that after about 1 to 2 seconds, the screen goes extremely dim...NOT totally black, but almost...just extremely dim. If I press the power button off and then back on, the screen will display at full strength for about a second, and then go dim again. Now, by "dim", I mean that you can still see a very faint ghost impression of the display, it's just so dim that it is almost totally blacked out (that is, even after it dims out, you can still faintly see the self test graphic floating around, it's just very faint).
Based on the problem as it existed prior to this "dimming" reaction (that is, it worked properly with some "assistance"), and based on the fact that the screen WILL display properly, if only for a moment, I am guessing that the problem is not a bad LCD screen (?). It seems that maybe a component is overloading?
Anyway, my question to you is, does this sound like it could be the 2N7000 FET going bad? Or, should I be looking elsewhere for the source of the problem?
I am currently testing each individual component, and so far all are testing good, including the FET. I'm just hoping you might lend some insight on what you think it might be, so I can better know what I am dealing with.
Many thanks for your help and your informative blogs.
Cheers-
Charles
admin
January 14, 2012 at 9:59 pm
Hi Charles,
Display shutdown after 2 seconds can be caused by bad backlight, dry joints, in the high voltage transformer, output voltages from the smps not stable and bad components in the high voltage transformer area. If you have an extra backlight i suggest that you replace it first.
Jestine
Czedric
April 1, 2012 at 1:40 am
Hey Jestine,
Thanks for the detailed directions. Do you have a schematic diagram (power section) of the same Dell model by any chance? Can you mail it to me at czed_01@yahoo.com ? Thanks!
-Czedric
Jestine Yong
April 1, 2012 at 9:37 am
HI Czedric,
Sorry I do not have the diagram. Try search from eserviceinfo.com
Jestine
neoanderson
August 5, 2012 at 11:25 pm
Dear sir i have dell 15¨monitor LCd, i replace 2AMP fuse and work for one week, today when i power on show blue linesand power of and same
Jestine Yong
August 7, 2012 at 6:57 am
HI Neoanderson,
Blue vertical or horizontal is the problem of bad lcd panel assuming if all the cable connection are intact. lcd panel can't be repaired and it need to be replaced.
Jestine
armando
October 2, 2012 at 3:30 pm
buenas tardes jestine.
mira tengo un monitor dell m170e5 quisiere ver si tu me pudieras ayudar
mira prende me da imagen 2 segundos y luego se pone oscura y el led de encendido esta de color verde
si lo apago y de inmediato lo prendo hace lo mismo
espero tu comentario y agradesco tu ayuda
Jestine Yong
October 3, 2012 at 2:58 am
Hi Armando,
Check for bulged e-caps, bad high voltage transformer or even one of the backlights have problem.
Jestine
Sherlyn
November 28, 2012 at 9:29 am
Hi, I came across your page while searching for information on Dell Monitor. I am using Dell Inspiron 531s monitor and the power just shut off a moment ago. I tried to unplug the cable and plugged it back but it does not work and I have even tried to connect the cable to my laptop, somehow the power on the monitor is still off. How can this be repaired or is it totally dead beyond repair?
Jestine Yong
November 29, 2012 at 7:04 am
HI Sherlyn,
You need to send to the repairer to check for you. If you have the electronics repair knowledge you can open it up and look for bad e-caps, fuse and etc.
Jestine
Rob Martindale
April 10, 2015 at 11:35 am
Hi Jestine. I have a Dell E173FPc. I have looked at all the comments about repairing these monitors, but my symptom is a bit different.
When I power the screen on, the green power light comes on, the display comes on for one second, then the backlight turns off. If I shine a bright light on the screen I can see that the image is still there. I have replaced the 6 capacitors as suggested on many sites regarding this particular monitor, but it did not help. I suspect the power transistor is the problem, do you agree? If so, do you know which one I should use as a replacement? Thanks.
Jestine Yong
April 11, 2015 at 9:39 pm
HI Rob,
Yes you need to check those transistors. Get the original number if possible. By the way you can also visit this link below for more ideas:
https://www.jestineyong.com/lcd-tv-and-lcd-monitor-shutdown-problem/
Jestine