⟐ Answered marzo 25, 2026 at 12:13 GMT-7

this lcd monitor samsung syncmaster 931sw (19 inches) show the picture normally (of seven or snowleopard) for 2 sec then turns black , if you look at a certain angle you see that the picture is still there but as if there was no backlight anymore

is there something i could do to repair it?

⟐ Commented febbraio 24, 2025 at 11:19 GMT-7

The issue:

Recently the monitor shuts off every 1~2 minutes, and after another 1~2 minutes turns back on. This cycle goes over and over. A few observations are as follows.

1. During the turn off, its green power button also turns off (the power button will not become orange). That means, it is not just the display that goes off, but it seems the whole power of monitor goes off. I suspect this is a power issue.
2. During the time when the monitor is on, there is no problem with the display itself. I doubt it this is the issue with the graphic card of a driver related issue.
3. Changing the power cord, or power outlet does not help. It is also connected firmly.
4. Changing the cords of either VGA, HDMI, Display port and their connectors does not affect the issue.
5. Using a different laptop/PC or operating system connected to the monitor does not affect this issue. Also, my laptop works fine with other monitors.

My attempt to fix it:

I suspected this might be a bad capacitor on the power board. I neither found a bulged capacitor by a visual inspection, nor there was a smell or noise from capacitors. However, I ordered a couple of capacitors online with the same specs, and replaced some of them on the power board. The issue still persists.

Question:

I do not think I am able to find which component on the board is causing the issue. So, I want to just order a whole board from a vendor.

Before spending time and money on ordering a board, I want to (almost) make sure if it is the power board issue at all, or maybe the main board (graphic board) issue?

Thanks.

⟐ Commented marzo 14, 2026 at 5:14 GMT-7

I'd like to know what specific components to look into for this kind of problem?

Thank you!

edit:

Currently tinkering with the board and I'm looking at two mosfets that might be overheating. I checked with the multimeter and they're both around .450-.470v.

K15A60U (with its own heatsink)

LD7904jgp7 (no heatsink, and near the K15A60U's heatsink)

Still not sure though which one needs to be replaced.

⟐ Commented aprile 05, 2025 at 1:42 GMT-7

Dead means absolutely dead – no power light, no sound to indicate it has switched on, no message about powering off in a few seconds to save energy, no sign of a backlight.

I have taken it to a PC repair shop and to an electronics company that deals with monitors (but more usually the industrial type) and both say no blown fuses, no bulging capacitors and that the power board is OK. The latter thinks the display panel itself is probably OK.

Since there is no power light, which is presumably low voltage, I'm thinking this must mean something is causing the power board to trip or shut down (almost instantly). Is it (almost) inevitably the mainboard or has someone any other suggestions? Would I be right to think the power board is capable of shutting down when feeding into a short or too high a load or demand from the mainboard?

⟐ Commented giugno 11, 2024 at 6:58 GMT-7

I was wondering if someone could give me some advice? I've never fixed anything electrical and would like to give it a shot.

My LG - 34UM95-P UltraWide monitor stopped working earlier this week. It won't power on, the white LED light near the joystick at the bottom of the screen is no longer turning on - neither is the monitor itself.

I've changed the fuse in the plug, but no joy.

I've had a look online and it's taken me down a bit of rabbit hole, I found one post that suggests the issue might be related to a EEPROM chip, perhaps it needs replacing or rebooting?

Wondering what tools would be useful to get to try and fix this monitor?

The monitor is in great condition for its age - purchased in 2014 - it's not been knocked about, I think something has just burned out (I have no idea).

It might be unrelated, but worth mentioning. I mainly used it with a MacBook Pro connected via Thunderbolt port. Never had any issues with this. In the last year or so a second PC laptop has occasionally been used with the monitor. Connecting via HDMI.

Sometimes the HDMI connection seemed a bit shaky, the monitor would make a white noise/static sound almost as if it was cutting out but only for a split second. Trying other HDMI ports on the monitor didn't seem to make a difference. Unplugging the HDMI lead and giving it a blow seemed to temporarily fix it. It was very random.

The monitor finally stopped working after the PC laptop performed a windows update.

The PC laptop wouldn't connect to the monitor and the image on the laptop was jumping all over the place. The monitor was blank, no power. Not sure if this is related?

Hope someone can offer some advice.

---

UPDATE #1

I've managed to open the back of the monitor. Images attached.

UPDATE #2 - Saturday, May 28, 2022

Test power adapter
I've tested the power adapter, multimeter showed 19v. So at least I know that's working as expected.

Test connector
I was unable to get the red probe deep enough into the connector, so I put it on the metal coming out of the connector, see red circle below. The black probe on a screw on the board, see black circle in the image below.

The multimeter was set to resistance mode, and it beeped.

I also tried the multimeter on two other resistance settings. First on a setting of 200, the reading was 01.0 then I changed the setting to 2k, the reading was .001

Test connector with power cable

Set multimeter back to DC voltage mode, setting 20. Plugged power cable in and turned the power on. Black probe on the same screw as before, and red probe on L713 , gave me a solid reading of 19.20

⟐ Answered febbraio 16, 2026 at 5:47 GMT-7

Defective CCFL backlight may have the following symptoms: Screen flashes on red/pink and goes off. Picture stays on in red and slowly be come normal. Picture flickering with dim display. Picture flickering on and off. All these symptoms indicate that the LCD backlight lamp (CCFL Lamp) has reached the end of its life.

I'm looking for more information on replacing these. The bulbs are so cheap as compared to a new LED. Has anyone done one of these? Do you have any sources for Apple LEDs? Here is a guide on doing it: http://www.lcdparts.net/howto/troublesho...

Another source: http://www.suburban-electronics.com/ccfl...

We might be able to put together a guide and source page.

Any suggestions or links?

⟐ Commented febbraio 09, 2015 at 5:42 GMT-7

I was on the computer then all of a sudden the screen turned off for a second and when it came back on it was white ish i can still see whats on the screen its just hard to read it has like this layer of white over it ... i tried to google it but no luck ... it also has really faint lines in it maybe 10 going horizontal i ran a scan but nothing idk what it is so can some one help me please !!

⟐ Commented dicembre 27, 2020 at 20:23 GMT-7

I have a Dell S2240L monitor. One day, a vertical red line appeared on the monitor as shown in the picture. Initially, it went away on its own or sometimes a gentle press on the screen made it go away. However, it doesn't anymore.

I have tried fixing with PixelHealer, I ran it for about an hour and a half, but doesn't seem to make any progress. This line of pixels can only be changed to either red or black (as far as I know).

I have seen people suggesting to take apart and check for loose connections inside. But I don't know how to take it apart as there aren't even visible screws anywhere. I am not afraid to do so if I know how, I have disassembled other monitors before, but I don't want to break it.

It should still be under warranty when it showed this line but I have lost the warranty slip unfortunately.

Do you have any suggestions in fixing it? Or an idea how to take it apart? Thank you.

Pictures of the monitor :

⟐ Commented agosto 02, 2024 at 0:04 GMT-7

I have a Hp27b monitor that shows no signal on both the hdmi and displayport inputs. I have tried manually selecting hdmi or displayport on the monitor.

I tested this on two different laptops and both laptops are able to detect and identify the monitor on the laptop end. I tried updating the monitor driver and still the issue persists. The laptop is able to send the signal to the monitor, I believe the monitor itself is not receiving the output from the computer. I also tried different hdmi and displayport cables and same issue. I was able to get a signal on another monitor as well so that eliminates the laptop itself having issues.

Would this be hardware issue of the monitor? If so, would it be the logic board or the cables itself?

Thanks for reading.

This is what shows up right away, I don't recall if it's supposed to be show the hp logo when powered on.

Yes I can view the entire menu perfectly, I can browse to change contrast, viewing mode, input etc..

⟐ Answered ottobre 23, 2022 at 17:30 GMT-7

Yesterday I was cleaning my monitor with Colin (cleaning agent). I directly sprayed it on display and wiped it with a dry cloth. After cleaning, I thought to turn on my PC and check for the display but it worked fine. Today when I turn it on my PC I saw that there were some blue lines in the middle of the display. What should I do now? Please assist me

⟐ Commented agosto 01, 2025 at 19:41 GMT-7

⟐ Answer accepted aprile 25, 2016 at 19:19 GMT-7

⟐ Answered giugno 25, 2024 at 2:23 GMT-7

Sounds to me like a lose connection or something. I'm routing the audio out through the headphone jack and even when the display goes, the audio stays, so it's not the cable. Also when the display goes, the backlight stays, so It's not that.

Any suggestions would be much appreciated.

⟐ Commented dicembre 31, 2018 at 8:03 GMT-7

Here are all of the pics: https://photos.app.goo.gl/gDMsz4suDAaQmz...

Thanks!

⟐ Commented marzo 03, 2026 at 7:34 GMT-7

I have this monitor HP Z27q 27-inch IPS 5K Display  https://support.hp.com/ca-en/document/c0... which purchased in faulty condition for $15, and I am hoping I will be able to repair it.

The monitor has a pink glowing hue from the bottom left corner that occurs 3 to 5 seconds after powering on. I have attached two pics to show the screen is functioning normally when powering on. The previous owner also mentioned that sometimes the screen will flicker on and off but I have not been able to recreate that since I bought it.

I am reasonably comfortable taking apart electronics and I have replaced displays before but I am kinda clueless as to what I am looking for.

Thanks in advance.

Edited to add pic of the panel:

Edit: Monitor completely torn down. There are 6 pin connectors on each end of a hard pcb led strip. Not sure how o test these or where to get a replacement.

Edited to add the model number of the led strip: LM41-00102A. Google brings back zero relevant results.

I think they are epoxied to the body as they dont seem to be removable and i cant see any screws.

Edit: Googling “sjm-1 94v-0” is bring back some relevant results at least.

Update,

I reassembled the monitor as I am going out of town for a while and decided to deal with it when I return. After reassembly the monitor is functioning properly for the past 4 hours.

⟐ Commented novembre 01, 2023 at 15:18 GMT-7

⟐ Answered gennaio 04, 2023 at 1:30 GMT-7

My monitor won't lite up. The power button is lite (green) but no display.

⟐ Commented luglio 25, 2021 at 12:05 GMT-7

When first powering on, the backlight comes on at full strength to show the blue Philips logo, very quickly dims to about half brightness, then shuts off completely. The center row appears to dim more than the edge rows.

Power Board:

I’ve disassembled the monitor to attempt a diagnosis. The connection to the mainboard seems fine - the 19V pins all supply ~20.2V, the 5V pins are at ~5.5V, and the ON/OFF and DIM pins have 3.3v on them during operation.

Mainboard pins:

The LED output pins seem questionable. The pins are labeled LED +V and LED-V, without saying what those voltages should be. There are 4 pins (leading to 4 rows of LEDs), each of which show 11.5V in operation - both during the initial period of backlight ON, and after it shuts off. The return lines are combined, and show some variation - during initial backlight ON period, they show up to 45V (approximately the outgoing voltage for all four LED strips). After the backlight stops working, they show ~30V.

LED pins:

Is this a power board issue? Or should I be looking downstream at the LED strips? There was no brightness problems before the sudden onset of this problem, but there is a bit of variation in how the strips behave currently.

⟐ Commented maggio 23, 2024 at 16:28 GMT-7

Here's my issue: my screen (a Samsung SyncMaster 245B) stopped working recently, the blue LED indicating power still lights up, but the panel itself stays black (it usually shows a grey box when nothing is connected to the screen at the very least). So I'm wondering if the panel itself is dead or if it might be another problem.

And I'm also wondering in case of the actual death of the panel, is it worth replacing or should I straight up buy another screen instead?

Thanks for your time and your answers to come ! :)

⟐ Commented ottobre 31, 2022 at 9:42 GMT-7