Samsung n710 S power off when vga connected

[dellxps15]

hi, a m8 bring me 3 lcd. 2 was able to fix by replacing soem bad caps, while this samsung shut down when i connect vga cable to a pc.

the situation is very similar to this one on that thread:

https://www.badcaps.net/forum/showthread.php?t=14654

i've checked capacitors and changed 2 that give a bit bigger value as expected, but still the same.

without vga cable it give image and the no signal logo on screen.

edit: found this other post googling

https://www.badcaps.net/forum/showthread.php?t=10693

but if i have to replace the se7889 ic, it will costs about 11€ shipped to italy, while on turkey some seller sell brand new video board for 13€ ship included...

[viziks]

Re: Samsung n710 S power off when vga connected

Does the monitor shutdown completely like switched off "No power,No Led" ?
I have fixed 2 such monitors by replacement of mains filter 450V one although from your picture of board it was a different board. See my post below :
https://www.badcaps.net/forum/showthread.php?t=22844

Samir

[dellxps15]

Re: Samsung n710 S power off when vga connected

yes it completely switch off... gonna read your thread

tnx very much for reply.

edit: bought that capacitors: 3.9€ , changed and it do the same

any other tips i can check ?

[viziks]

Re: Samsung n710 S power off when vga connected

Please monitor the voltage across mains filter,Normally should be a constant 320Vdc.If this voltage is stable then you need to check +5V and +12V and see which one shuts down.There can be a short mosfet driving the Inverter transformer.
If you do not connect VGA cable does the monitor remain on with front display showing "No Signal "?
Have you replaced the Vga board from working monitor to confirm which of the 2 board is defective ?

[budm]

Re: Samsung n710 S power off when vga connected

It may have to have EEPROM reset:
https://www.badcaps.net/forum/showth...set#post130313
I remember seeing one of the thread that said after the caps are replaced the NO SIGNAL will be on the screen, if the VGA is connected, then the screen will black out as if it goes into standby mode.

[dellxps15]

Re: Samsung n710 S power off when vga connected

lol didnt recognize it passed so much time. after that year i took back the lcd and tryed solder pin like the post but nothing happen. monitor is ok without vga cable. it power on and display the no cable connected picture, but as soon as i connect the vga cable it power off. voltages on pins that goes to the psu are:

without vga cable
1) 3.72v
2) 0v
3-4) 5 volt
5-6 )0 volt
7-8) 12.5 volt

with vga cable connected:

1) 0v
2) 0v
3-4) 5 volt
5-6 )0 volt
7-8) 12.9 volt

edit: ive also manually resoldered each pin of eeprom, but same as before...

[petehall347]

Re: Samsung n710 S power off when vga connected

i know i might be wrong but is resolution set correctly ? was just a thought .

[dellxps15]

Re: Samsung n710 S power off when vga connected

monitor turn off even if i plug a vga cable with vga to dvi adapter and without connecting dvi to anything......

[piernov]

Re: Samsung n710 S power off when vga connected

Probably a dead Novatek chip (the one with the sticker on it). Sadly it contains a ROM that you would need to extract and then flash onto a new chip. I still don't know how to do that though… Maybe with the help of an RT809F?

[dellxps15]

Re: Samsung n710 S power off when vga connected

i think so too, but dont have that programmer and also dunno if original firmware is available, plus that chip costs about as a working lcd.....