Question about BenQ FP71G 17" LCD Monitor

2 Answers

Benq lcd c5707 transistor issues

I have a Benq flatscreen lcd monitor that has a back light issue. I am not able to llocally source the c5707 transistors and have substituted the transistor pair that are blown with similar V and current NPN's. Now the monitor turns on for one second then the backlight goes out.

Will the correct transistors fix this or could there be another fault?

Posted by on

  • martindaniel Oct 23, 2008

    Ok thanks, I gathered that. In my case the capacitors between the transistors (the o.22uF caps) both had dry joints and were loose. I replaced these and resoldered the transformers. I have tried other similar NPN transistors but the result is the same. Turns off after one second. I will just have to wait for the correct transistors to arrive in the mail.



    However, I replaced the transistors with common MEJ3055 transistors from Jaycar on a 15 inch dell (aka benq) and it works fine, but these do not have the same result in the benq 17 inch monitor which turns off after one second, so again, I think I just need to wait.



  • emmcay_elect Jan 21, 2009

    Hello sir, i have also the same problem of c5707 shorted. and i tried tip3055 same trouble after a second display disappear. Is there any parts involve to be replace? BENQ model Q7C3.thank you.

×

2 Answers

  • Level 1:

    An expert who has achieved level 1.

  • Contributor
  • 1 Answer

You need transistors with hfe greater than 300. They are harder to get and you should use the producter`s original transistors 2sa5707.

Posted on Dec 15, 2009

  • Level 2:

    An expert who has achieved level 2 by getting 100 points

    MVP:

    An expert that gotĀ 5 achievements.

    Governor:

    An expert whose answer gotĀ voted for 20 times.

    Hot-Shot:

    An expert who has answered 20 questions.

  • Expert
  • 105 Answers

These transistors short due to deterioriated solder joints on the leads of the transformers. Unless you resolder the connections you will have shorted transistors again.
Monitor Mike

Posted on Oct 22, 2008

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

BenQ Q24W5 LCD monitor circuit diagram


HI.............


Repairing BenQ 17′ LCD Monitor

benqlcd.jpg
I came across a common fault problem in BenQ 17′ LCD Monitor. The problem is have power but no display. Once you has opened the LCD cover, check the pico fuse for open circuit (very common), the push pull transistors C5707 for short circuit and the Buck royer circuit p-channel fet FQU11P06 also for short circuit too. For your information, if you can't get the FQU11p06 you can always use FU9024N as a replacement. Resolder all the high voltage transformer pins and replace the components above and I'm sure you will bring back the life of this BenQ 17′ LCD Monitor.
You may go to this fairchild semiconductor website to download the spec of the FQU11P06 P-channel FET.

http://www.fairchildsemi.com/ds/FQ/FQU11P06.pdf


GOOD LUCK.............

Sep 23, 2011 | Computer Monitors

1 Answer

Repair BenQ Q24W5 monitor


HIIIIIIIII...................


Repairing BenQ 17′ LCD Monitor

benqlcd.jpg
I came across a common fault problem in BenQ 17′ LCD Monitor. The problem is have power but no display. Once you has opened the LCD cover, check the pico fuse for open circuit (very common), the push pull transistors C5707 for short circuit and the Buck royer circuit p-channel fet FQU11P06 also for short circuit too. For your information, if you can't get the FQU11p06 you can always use FU9024N as a replacement. Resolder all the high voltage transformer pins and replace the components above and I'm sure you will bring back the life of this BenQ 17′ LCD Monitor.
You may go to this fairchild semiconductor website to download the spec of the FQU11P06 P-channel FET.


http://www.fairchildsemi.com/ds/FQ/FQU11P06.pdf



GOOD LUCK............

Sep 23, 2011 | Computer Monitors

1 Answer

Benq T905 Monitor's green light turns on and then off


Check for blown MOSFET IRFU9024N and transistors C5707/5706, and fuse in the inverter circuits section. Also look for bad caps with bulging top/seal. See some pictures of failed Dell monitors (BenQ made alot of monitors for Dell), http://s807.photobucket.com/home/budm/allalbums

Mar 14, 2010 | BenQ T905 (Black, Silver) 19 inch LCD...

1 Answer

Benq t7q3


look at the 3 amp. fuse on the mainboard! By the way, you can buy very cheap USB light, wich are working with a small lighttube. Use the transistors of their generator!

Mar 09, 2009 | BenQ T705 17" LCD Monitor

1 Answer

BenQ 17inc LCD Monitor


change c5707 transistors ...all 4 of them plus fuse

Feb 10, 2009 | BenQ FP731 - 17" LCD Monitor

1 Answer

Back light goes out after start up


You have BenQ syndrome.
Sounds strange I know, but the power supply in your monitor is a BenQ manufactured part.
The problem is in the inverter section of the power/inverter board.
There are 4 small transistors (marked C5707) 1 or possibly 2 of these will have shorted out. Using a multimeter find the shorted one, and replace both of that pair, even if only one is shorted out.
There could also be other underlying issues as well that caused the transistor to fail in the first place.

Mar 28, 2008 | Dell E172FP 17" LCD Flat Panel Monitor

1 Answer

Benq 17"Lcd monitor fault


Resolder the power transistors on inverter board and also check them.If display is not there at all some of this 4 transistors C5707 should be defective.Check associated fuse and Fet which drives the transistor.

Also check with Benq ,Normally offers three year warranty.

Samir

Mar 23, 2008 | BenQ FP737S-D 17" LCD Monitor

6 Answers

BenQ FP731 17" LCD Monitor Problem


Connect it to another device, if you get the same result the backlight is bad! These can be replaced, but can be costly!

Nov 14, 2007 | BenQ FP731 17" LCD Monitor

6 Answers

Dell E172FPb 17" LCD Monitor Problem


Your inverter power supply has gone bad. You will need to replace the whole board or replace the the 2sc5707 transistors in the inverter area. Check out this link for installation videos and how to for that model
http://www.lcdrepair.us/Installation.html
They also sell the whole board as well as repair kits

Oct 27, 2007 | Dell E153FP 15" LCD Monitor

10 Answers

BenQ FP731 Screen briefly displays then turns off


hi. i had the same problem and fixed it. the problem are the 4 transistors (C5707) one of more are shorted (Q739,Q740 and Q759, Q760). Also the fuse PF751 (3a) has to be replaced in most cases. In my case i replaced the fuse and 1 transistor (C5707)

Dec 06, 2006 | BenQ FP731 17" LCD Monitor

Not finding what you are looking for?
BenQ FP71G 17" LCD Monitor Logo

Related Topics:

2,199 people viewed this question

Ask a Question

Usually answered in minutes!

Top BenQ Computer Monitors Experts

Tony

Level 3 Expert

2598 Answers

Matthew Spark
Matthew Spark

Level 3 Expert

1042 Answers

Donald DCruz
Donald DCruz

Level 3 Expert

17129 Answers

Are you a BenQ Computer Monitor Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...