BenQ - Monitor vertical lines issue

[donst]

Hi all,

Have a problem with my monitor and hoping to receive some help.

Basically what the problem is that i have a BenQ FP241W monitor that only displays vertical coloured lines. When i switch the monitor on i am instantly greeted with the lines. This is the case on any PC or other device i connect the monitor to. I have connected the monitor to two PCs via a VGA cable and my blu-ray player via HDMI. When attached to my PC, the colours/lines both change depending on what is on screen(the lines are not set). Same goes for when attaching it to the blu-ray player, in this case however you notice the moving picture, nonetheless the display is still dominated by lines.

This issue has been a problem for other 4 to 5 months now. Before, i use to be able to bang the monitor on the side where the buttons are located and the display will show up as normal. That does not work anymore. Also, in the past i use to be able to leave the monitor on a while (20-30mins) and the picture would eventually show up as normal. This is not really the case anymore, up until a month ago i would leave it on for maybe an hour and it would display as normal, although recently i have left it on for maybe an hour and a half and the picture will not show up.

I've opened the back up and looked at the connections to see if any have come loose (i thought the banging solution may have suggested a loose connection somewhere) but they all seem to be ok. I have also looked at the capacitors to see if any have blown but no problem there either.

Does anyone have any ideas on what it could be and what i could try? i really do not want to toss this monitor away. Buying replacement panels etc is not really an option.

Pictures attached. (Its not always dominated by blue)

Anyone with any ideas? All help would be much appreciated.

Thanks.

[selldoor]

Re: BenQ - Monitor vertical lines issue

Try removing, cleaning and replacing the lvds cable that is between the main or video board and the panel. (care with the panel connector) If that doesnt help then you may have damaged the screen by banging it!!
Good clear in focus pictures of the boards may help.

[donst]

Re: BenQ - Monitor vertical lines issue

Hi, thanks for the reply.

Yeah, i guess banging the monitor was a little 'caveman-esque', hopefully it's not gone beyond the point of repair.

Also, how do i go about cleaning the lvds? As simple as a cotton bud with white spirit and wipe on either end of the cable?

Pictures attached.

[selldoor]

Re: BenQ - Monitor vertical lines issue

No - not white spirits - it will leave a residue. Ideally Isopropyl alcohol

http://www.specktra.net/t/101134/uk-...l-alcohol-from

For the flat ribbon cables -the ones at the top in pic 2- (tcon) quite a few people have success just rubbing across the contacts with an eraser.
You need to be v careful as this area gets hot and the clips that hold the flat cables become brittle.

The multicoloured wire cable from the bottom of the tcon to the main board
you just clean as best you can with the IPA on a small brush or cotton bud
as long as it doesnt fray.

There is also a small white fuse on the tcon just above the bottom connector
it is labelled F3 . Can you test it and also record the dc voltage on it.
As it is F3 there are probably more fuses on the board if you can find and check them

[donst]

Re: BenQ - Monitor vertical lines issue

I have methylated spirit, will that do? If not, i'll pick up some Isopropyl.

As for the fuses, the fuse you refer to is in fact labelled F5, so does that suggest that there are four other fuses on the board, or am i mistaken? I've searched the board but can only find two others. One is a little further above F5 and that one is labelled FL1, and then you have another to the right of that fuse labelled FL2.

I've measured the dc voltage for all 3 and i get nothing for both FL1 and FL2 and for F5 i get 4.92.

[donst]

Re: BenQ - Monitor vertical lines issue

Is the voltage for F5 ok?

[selldoor]

Re: BenQ - Monitor vertical lines issue

Hi - thought I had replied to this - dont know where it has gone!!

I should have thought F5 should be 5v so probably near enough.
FL could be fusible link or an inductor either way I think it should have a voltage. How are you measuring? You should have meter on 20vdc black lead on an earth screw use red probe to test voltage at each side of fuse.
If you did not do that please retry. Also with the power off can you
test all three for resistance - meter on ohms 200.
There looks to be 3 voltage regulators on the bottom of your pic
2 have 3 legs and the tab and one has 2 and half legs and the tab.
With the power on test the voltage on each leg and the half leg as you did with the fuse - can you read the part numbers for these?

[donst]

Re: BenQ - Monitor vertical lines issue

Yep that's pretty much how i measured the fuses, although sorry i forgot to give you both sides. On F5 i get 4.93 on the left and 4.92 for the right. With both the FL fuses i still get 0 on both sides when measuring at 20vdc but when using 2vdc i get 0.05 and 0.05 for FL1 and for FL2 i get 0.08 and 0.08.

Testing all three with the power turned off and ohms at 200 i get the following:

F5 - 0.27
FL1 - 2.30
FL2 - 2.20

Results for three voltage regulators measured with 20vdc (starting from left to right on picture)

U3 - 0, 2.51, 3.34
U2 - 0, 3.34, 4.90
U1 - 2.18, 3.43, 4.9

[lexwalker]

Re: BenQ - Monitor vertical lines issue

Yeah, i guess banging the monitor was a little 'caveman-esque', hopefully it's not gone beyond the point of repair.

Also, how do i go about cleaning the lvds? As simple as a cotton bud with white spirit and wipe on either end of the cable?

Use contact cleaner, which does not leave residue. Also looking at those vertical lines, I would say forget about repairing that as very likely a panel problem. If it were a dirty LVDS then you would get shaky pictures, colors shifts, shimmering, etc. But vertical lines, especially always in the same area (and same patterns) are very much LCD panel fault.

[donst]

Re: BenQ - Monitor vertical lines issue

Use contact cleaner, which does not leave residue. Also looking at those vertical lines, I would say forget about repairing that as very likely a panel problem. If it were a dirty LVDS then you would get shaky pictures, colors shifts, shimmering, etc. But vertical lines, especially always in the same area (and same patterns) are very much LCD panel fault.

Yeah,thanks for the advice, i've been told similar before, but if there is even the slightest chance of getting it up and running again then i'd like to give it a go as it's a great monitor.

Selldoor, did you get the results?

[selldoor]

Re: BenQ - Monitor vertical lines issue

U1 looks ok
U2 & U3 cant really tell without the part numbers.

If they are fixed 2.5 and fixed 3.3 then they may be ok there should be a clue
in the numbers like 1117-33 or 17-33 0r something-25

[donst]

Re: BenQ - Monitor vertical lines issue

Part numbers are:

U3- 1161 950T63
U2 - RT164A 33PL8GEOL
U1 - MM 1117 A B632

[budm]

Re: BenQ - Monitor vertical lines issue

You have bad panel.

[selldoor]

Re: BenQ - Monitor vertical lines issue

Those VRs are good - think its time to call it a day unless you can pick up a new/ replacement panel v cheap.

[donst]

Re: BenQ - Monitor vertical lines issue

Ok thanks mate, it's a shame but i guess i always knew it was a lost cause anyway, never mind.

Just out of interest, and if you or anyone else does not mind explaining, why is it that when a and led panel goes bad why is it always a 'no hope' in regards to fixing it? For example with the issue i have with this monitor, what exactly on the panel would cause the lines on the screen and why would that not be fixable? I understand it is impossible to fix, due to many people stating so, but i'm just curious as to why.

[tom66]

Re: BenQ - Monitor vertical lines issue

The chips (TFT Drive IC / Source and Gate Drive IC) that drive the panel are bonded to the glass, so if they fail, the whole panel needs replacing.
Sometimes, you can apply a tab "shim" to apply pressure to a bond, this can fix or temporarily fix some problems like this:
http://www.youtube.com/watch?v=purk_SyiT44