TV Forums

Free Games TV Forums

  Main Index FORUM
HOME
Search Posts SEARCH
POSTS
Who's Online WHO'S
ONLINE
Log in LOG
IN
Rules & FAQ RULES
F.A.Q.

Crumbtrail TV Forums: TV Equipment: TV Repair Forum:
Samsung s27d390 - backlight issue

 

 


webel13
New User

Jun 29, 2016, 12:57 PM

Post #1 of 3 (4694 views)
Shortcut
Samsung s27d390 - backlight issue Can't Post

Hello!

I was hoping to find some input in regard to my issue.

When I turn my s27d390 on, the backlight flickers 3-4 times, then shuts off. The picture itself is being displayed perfectly fine if i shine a bright light onto the screen, it's obviously just extremely dark.

Picture of its insides

The screen seems to only have one one electric board(as I understand, my issue is most often caused by a bad inverter - which must be built into that single board), and I have already tried replacing that entire board - the issue remains the same, so it's 100% not the board.

Nor is it bad wiring(at least in the sense that twisting certain wires would cause the backlight to blink), so my two guesses are the LEDs themselves or my power supply.

Since I'm only an amateur in electronics, I'm hoping someone here can provide me with some tips.
I'd like to test my power supply first, because the replacement is cheap and easy to get(I'm bound to burn out a LED by mistake when testing them..).

So, what would be the best way to test the 12volt power supply box? If i attach my multimeter to its leads while plugged into the screen and then turn my monitor on - would a sudden drop/rise in voltage be an indicator that the fault is in the power supply?

As for the LEDs being bad, could a single resistor/LED(obviously it can't be all the LEDs that are faulty) on the strip cause this to happen? Or can i perhaps assume the LED strip is in working condition since it manages to blink and stay on for about a second?

Thanks for reading! Any suggestions will be greatly appreciated, and I'm willing to spend any amount of money to fix the issue, just because I'm stubborn.

Kind regards!


(This post was edited by webel13 on Jun 29, 2016, 1:03 PM)



jts1957
Veteran


Jun 29, 2016, 3:24 PM

Post #2 of 3 (4676 views)
Shortcut
Re: [webel13] Samsung s27d390 - backlight issue [In reply to] Can't Post

Well then buy a new monitor and this time the first thing you do is turn the backlight (LED) intensity down to say 30%.

Since you have picture with a flashlight, your PS box must be O.K.

LEDs are in series. If monitor has been running at maximum intensity since day one, chances are good that one (or more) have failed.

CAREFULLY taking the panel apart to expose LEDs, take two 1.5V batteries connected in series, and observing proper polarity, test each LED.


-------------------------
Location: Far, Far Away


Lazyjack
New User

Mar 15, 2018, 8:52 AM

Post #3 of 3 (3679 views)
Shortcut
Re: [webel13] Samsung s27d390 - backlight issue [In reply to] Can't Post

Hello webel13,
i have a dead s27d390 without any function. The power supply seems ok. I want to check the inside wiring and board but i donīt know how to open the case ;-( Please can you explain me, how to open it?
Many thanks!

With best regards
Max

 
 
 


Search for (options) - Page loaded in: 0.20 s on (CGI/1.1)