Samsung LE40B550 won't show picture

dmward71

Standard Member
hello Names Dennis

I have searched this forum for answers but can't find anything

I have a LE40B550 samsung, that plays the welcome sound and then you can hear the channel of the tv but you can only see the shadow of the picture under the screen. when viewed very closely

I tried doing a factory reset with the help of a torch as mentioned in another thread on here.
I took the back off to see how the capacitors where and they all looked fine no swelling or black marks.

could this be the Ip Board ? or something else.
I have to use a torch to be able to see the menu options.




 

dmward71

Standard Member
Wow i'm overwhelmed by all your replies.

oh wait there hasn't been any.

on looking at most threads, is there no one technical on here to help ? most threads seem to go un answered.

anyone suggest another forum that might be able to help.
 

JayCee

Distinguished Member
The technical name for your symptoms is "no backlight" and the backlight source is a series of thin glass tubes mounted horizontally behind the screen called "CCFLs", the power for the CCFLs is generated by the "invertor" which is the 2nd pcb in your pics.
But, the fault could be caused by the invertor, the power pcb or the main board...it can also be caused by 1 or more of the CCFLs being faulty.
 

dmward71

Standard Member
thank you for your reply.

should i just buy new capacitors anyway and replace. if so, just the 5 small ones on bottom left side or the two big blues ones to ?

are there any tests I can do to narrow it down myself. ?

do Tv repairs specialist still exist to come out and check out things like this?

I think its worth repairing as replacing will cost £300-500

I think its worth £££ to repair what you think ? im based in SE London
So I can get another IP board for around £45,
this thing here



even though this is not the back of my tv it looks like same Ip board and layout
 
Last edited:

JayCee

Distinguished Member
There are no tests you can do without sophisticated testgear.
There are still honest Tv repairmen that will come out and give you an estimate or you can take it to them but there will be an examination fee or callout charge. You would need to check your local papers and phone around.
You can examine the print side of the invertor board for any obvious dry joints but if you decide to replace it you must ensure you get the exact same replacement by noting the part nos on it.
As stated the fault can be caused by various things and you take a chance by replacing boards when you're not 100% sure if they're faulty.
 

dmward71

Standard Member
The technical name for your symptoms is "no backlight" and the backlight source is a series of thin glass tubes mounted horizontally behind the screen called "CCFLs", the power for the CCFLs is generated by the "invertor" which is the 2nd pcb in your pics.
But, the fault could be caused by the invertor, the power pcb or the main board...it can also be caused by 1 or more of the CCFLs being faulty.
out of interest what area are you talking about when you say 2nd pcb in pics
do you mean the one of the 4 big black things
 

JayCee

Distinguished Member
dmward71 said:
out of interest what area are you talking about when you say 2nd pcb in pics
do you mean the one of the 4 big black things
Sorry, it's the 3rd pic, that's the invertor board (PCB...Printed circuit board))
 

dmward71

Standard Member
would putting the same number board in but rev 1.3 cause any issues

BN44-00264C REV 1.3

I have rev 1.2 current in
 

dmward71

Standard Member
just a quick update, board was fine, it was one of the backlight tubes malfunctioning.
took it to repair place and got replaced & fixed.
 

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