Substitution For C5707 Transistor Use In Dell LCD Monitor
If you repair Dell LCD Monitor (E173Fpb and etc) you would know that most of the power blinking problem was due to a shorted C5707 transistor. This transistor is located nearby the high voltage transformer and when it have dry joints, the push pull transistor C5707 would go shorted. If you want to replace this transistor, you have to replace the other one also (because it comes in a pair to switch the high voltage transformer). The question is if you can obtain the original part number then it would not be a problem for you but what if you can’t get one? As for me i could source this part locally. If you can’t get the original part then the best is to get a substitution part number.
This morning while spoke to one of my repair friend in Miri Sarawak, he told me that he used C3303 as a substitute for C5707 transistor! I personally haven’t try it out but at least for those who do not have the original one can test and see. The spec for C3303 is a little bit lower than the original one but my repair friend told me it works! That’s the good thing about knowing lots of repair friends out there or in the market.
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Daniel
October 18, 2007 at 1:25 pm
I couldn't understand some parts of this article Substitution For C5707 Transistor Use In Dell LCD Monitor, but I guess I just need to check some more resources regarding this, because it sounds interesting.
freddyzdead
February 6, 2009 at 9:28 pm
I don't understand what would be hard to understand about such a simple concept as finding a replacement transistor.
The 2SC5707 is a fast switching transistor with relatively high gain (hFe) around 200 or so. In many places I have seen advice to replace it with MJE3005 or something similar. This may work, but not very well or for very long. The 3055 is intended for low-frequency audio applications and is completely the wrong choice for this job.
It is very important that the two transistors be matched, as they are used in a self-oscillating inverter configuration; if they have different gain from each other, they will conduct different amounts which will result in DC component in transformer which is a very bad thing. Will cause heating and blow things up. So, no matter what transistor type you use, use 2 of them. It is actually fortunate that this monitor uses 2 backlight inverters which are identical. Only one of them is usually faulty. That means you have a good one to compare the bad one with. Like a stereo amplifier.
It seems that a lot of the trouble with this inverter comes from the fact that the board is a very cheap consumer-grade material with very thin copper laminate, which cracks very easily and cannot tolerate heat or mechanical stress. This cheap board has no business being in a piece of equipment of this calibre. But it is seen everywhere, even in expensive equipment; there seems to be some undocumented rule that cheap board must be used for all non-digital parts of equipment, regardless of price. The only way this will ever change is for a large number of people to complain about it.
So, what are you waiting for?
-freddy
admin
February 10, 2009 at 8:27 pm
Hi Freddy,
Thanks for the contribution!
Jestine
ian brown
April 28, 2009 at 12:16 pm
i have four monitors that need this transister c5707 please help
admin
April 28, 2009 at 3:25 pm
HI Ian,
Try http://www.bluestar-online.com
Jestine
ramon martinez
May 6, 2009 at 11:43 pm
Hello I want to know how much this part will cost me since i am located in Florida. what is the price transistor C5707?
admin
May 7, 2009 at 11:48 pm
Hi Ramon,
According to blue Star Online website it is 0.99 cent each
jestine
Irwan efendi
July 6, 2009 at 7:25 pm
my benq lcd q731 display nothing but the led is on. i found 4 c5703 + 1 fuse 3a + 2 fqu11p06 are burned. what are the substitution for c5707 and fqu11p06. thanks
admin
July 7, 2009 at 11:33 pm
HI Irwan,
The best is to use back the C5707 or you can buy the part from http://www.bluestar-online.com As for the FQU11P06 you can try FU9024N.
Jestine
b. dobbs
July 9, 2009 at 5:34 am
All the searching I've done talks about the blinking power button but I don't have that problem. When I turn on the monitor, it lights for about 5 seconds then goes black but my power button stays lit without any blinking. Does this indicate a different problem??
admin
July 9, 2009 at 8:09 pm
HI Dobbs,
Check the backlight as a bad backlight could cause such problem.
Jestine
b. dobbs
July 10, 2009 at 2:01 am
I hooked up the monitor without the video cable attached and turned it on. It stayed on for about the usual 5 seconds and went black. I used a flashlight to see if I could spot the test pattern and there it was. Is this confirmation that it's the backlight? If so, where is it, how do I get at it and where do I find the correct replacement?
admin
July 14, 2009 at 9:16 pm
HI Dobbs,
Yes it could be backlight or the inverter board problem. As for the replacement of backlight, i would usually salvage from a junk LCD Monitor.
Jestine
Jeff
July 14, 2009 at 11:28 pm
Jestine, first of all thanks for putting this out there to help consumers like myself keep there electronics working! I have the blinking power button syndrome on the Dell 172fpb. I understand that I will need 4 transistors, how can I tell if I will need any of the other parts, fuses etc that other people talk about?
Thanks again!
Jeff
admin
July 15, 2009 at 7:28 pm
HI Jeff,
You need to check on the corresponding components especially the semiconductor before you are place an order of the 4 transistors.
Jestine
b. dobbs
July 16, 2009 at 4:11 pm
Are the voltages applied to the ccfl tubes critical?
admin
July 16, 2009 at 8:51 pm
HI Dobbs,
Yes as it can affect the brightness of the lamp.
Jestine
fabricio soares
July 28, 2009 at 10:54 am
como faço pra consequir esse transito ou a subistituta!!!
Jayasheela
August 6, 2009 at 6:47 pm
Is there any revision for C5707 ?? like C5707 4M ,C5707 5A, C5707 5F , C5707 5L C5707 6D etc, . . . . .
IF Yes, is there any problem if we use lower revision?? to higher revision ??
admin
August 6, 2009 at 8:58 pm
Hi Jaya,
So far have not seen any revision yet but i believe it will work on any revision for this transistor.
Jestine
ebrahim
October 3, 2009 at 7:37 am
Please, I want to know an alternative private Balchacy Transistor LCD 17P
We know the base figure C5707Notify me and him in the alternative, the Egyptian market, please kindly reply quickly because I have been working in the field of computer maintenance I have looked in the Alibdailalmtahp not شكرااا Finder for your cooperation with us
admin
October 3, 2009 at 10:50 am
Hi Ibrahim,
Sorry i don't understand what you mean. If you would like the original part you can visit http://www.bluestar-online.com
Jestine
Gabriel K Agbemenya
October 7, 2009 at 6:40 am
Another correct substitute for c5707 transistor is c5103. I have changed a couple of c5707 transistors with the c5103 and it works perfectly as the original part numbered. using the combination of both c5707 and c5103 wont have any problem.
Gabriel K. Agbemenya
admin
October 7, 2009 at 7:38 pm
HI Grabiel,
Thanks for the tips!
Jestine
cheap computers
October 28, 2009 at 8:48 pm
I personally haven’t try it out but at least for those who do not have the original one can test and see.
Chris
January 25, 2010 at 5:31 pm
I replaced the 4 2SC5707 transistors and still have the same problem. The power lite blinks. Any other suggestions?
admin
January 27, 2010 at 6:24 am
Hi Chris,
Try remove the pico fuse to see if the power light will still blink. If it not blinking anymore then check all the semiconductor in the inverter board especially the FET.
Jestine
Chris
January 27, 2010 at 12:44 pm
Thank you for the idea.
luis valdez
February 22, 2010 at 7:25 am
Hi! I would also like to share how I replaced the c5707 with 2sd1803. amazing! up to now it still works (almost 4 mos now).nte2524 or ecg2524 is also a good substitute.
admin
February 22, 2010 at 9:24 am
Hi Luis,
Thanks for the good sharing!
Jestine
George Nyangu
March 19, 2010 at 6:01 am
I have a dell lcd with C5707 shorted. I live in Botswana and to get replacement is a non starter please help where i can purchase the C5707 or substitute
admin
March 21, 2010 at 11:08 am
Hi George,
http://www.bluestar-online.com use to have a good service but now their service is not as good. I have no other sources other than the website above.
Jestine
tara
March 28, 2010 at 10:52 pm
Hello people...the kit can be sold on ebay.as low as $5.99 for the 7 pcs.
tara
March 28, 2010 at 10:54 pm
http://shop.ebay.com/sis.html?_kw=KIT+4+PCS+2SC5707+C5707+%2B+FUSE%2BFU9024N++E172FPB+E173FPB&_id=320301193969
Jason Musefu
May 7, 2010 at 5:51 am
My LCD monitor was blinking i replaced transistor c5707 with BUT 11AF.it has stopped blinking but the problem is that the display only comes for a few seconds.What should i do or what else should i change?
admin
May 7, 2010 at 8:30 am
Hi Jason,
Could it be that the BUT11AF is not suitable for replacement? Sometimes a wrong substitution number could cause the display to shutdown. Check the surrounding components and also the backlight because a bad backlight could cause the monitor to shutdown too.
Jestine
Dallas
October 28, 2010 at 12:18 am
Hi Jestine,
I have a Dell 2700 FPb that has recently started to spontaneously reset. The screen goes blank, the LEDs on the front bottom button bar all go out. Sometimes it will throw up the "Dell" splash screen and come back on by itself. It's almost as if the monitor was a computer itself. It seems like it is resetting. However, most of the time, once the screen goes blank, it remains blank.
Do you think I am having the shorted transistor problem? I removed the power board and I did not see any bulging capacitors. How can I tell whether it's the transistors or inverter?
Also, how can I avoid being shocked by one of these giant capacitors discharging on me?
Thanks!
admin
October 28, 2010 at 9:43 am
HI Dallas,
You can use a 100 watt bulb to discharge the big capacitor. Just short the two pins with the bulb 2 wires and the charge will be gone. In your case, if the main board is getting good and stable voltage then the MCU in the mainboard may have problem. The programs in it may have run and this will cause the symptom that you have described.
Jestine
bruce
November 16, 2010 at 6:51 pm
where can i buy these tranistor c5707 or other ones found in lcd monitors
19inc and 17inch
admin
November 17, 2010 at 6:31 am
HI Bruce,
Try this link:
http://www.richtechparts.com/search.html?sfield=&search=c5707
Jestine
Rob
May 2, 2011 at 10:08 pm
Jestine great job on the site!!! Very helpful as well as informative. My question is about the Dell E series 152-173 Fpb models about the C5707 and conversion to NTE2668 I am wondering if there is a conversion for the FU9024N FET at this time??? I like to try and cover all bases if the original isn't available. Thanks for the Hard Work and keeping up with the site.
admin
May 3, 2011 at 3:23 am
HI Rob,
Sorry no info on this but you can use FQU11P06 as a replacement for the FU9024N.
Jestine
Rob
May 4, 2011 at 5:36 am
Thanks for getting back to me so quickly Jestine.
Chance
September 23, 2011 at 4:46 pm
Early this year I got help on my dell lcd monitor after replacing two transistorC5707. But now I hav e a simiral dell lcd which had the same blinking problem andI replaced the transistors,then the blinking is gone but it only diplays for some 4 secons then the lcd goes blanck. Not even diplays for controls are shown. Please help.
Am impressed by your knowiedge. God bless
admin
September 23, 2011 at 8:43 pm
Hi Chance,
There could be bad tuning capacitor located nearby the high voltages transformer, dry joints in the high voltage transformer or even one of the backlight is bad.
Jestine
Stanley Onyedika
October 20, 2011 at 7:55 am
Pls, from your advice on how to fix the problem of C5707, u said i 'll need to replace the other one as well. Pls i want to know what other one you meant. Thank you a lot for your help.
admin
October 21, 2011 at 2:15 am
HI Stanley,
If the C5707 shorted then you may need to check on the P-channel fet like fu9024n or fqu11p06
Jestine
Md. Shahjahan
December 29, 2011 at 7:03 pm
Dear Sir
I need details specification of UC 3842 PWMIC.
Best Regards
Md. Shahjahan
admin
December 30, 2011 at 2:54 pm
HI Shahjahan,
Just type in the part number follow by the word datasheet and you can see lots of info about the part.
Jestine
mrshaikh
February 11, 2012 at 9:10 pm
c5707 1.base 2.collector 3..emitter
c2794 1.emitter 2.collector 3.base
it will work