HP L2208W vertical and horizontal lines

[wenter]

I was given this 22" LCD monitor. The issue it has is the following:

1) When turned on monitor shows up lots of horizontal and vertical lines
2) When it warms up most of the lines disappearing except some lines on the top part of screen, that never go away.
3) All capacitors on power supply/inverter board looks ok
4) All capacitors on logic board looks ok
5) Monitor is little over a year old.

What can be the cause of this issue?

What should I start troubleshooting with?

[retiredcaps]

Re: HP L2208W vertical and horizontal lines

2) When it warms up most of the lines disappearing except some lines on the top part of screen, that never go away.

Depending on how long it takes to warm up, you could using a hair dryer to see if it makes the lines disappear quicker or not.

Try warming up sections of capacitors at a time. If the hair dryer makes a difference the caps could have high ESR or there is bad soldering.

Caps can fail in a year as well if they were poorly made and subjected to a lot of heat.

[jetadm123]

Re: HP L2208W vertical and horizontal lines

When you see the vertical lines, try lightly pressing down on the top part of the LCD panel where the lines originate from. If the lines go away, then you may a defective LCD panel.

Try checking the voltage regulator (U12?). Record voltages at each pin.

If the above two check good, try replacing the the 5 caps on the logic board.

[wenter]

Re: HP L2208W vertical and horizontal lines

I warmed up different sections of power board and logic board with a heat gun on a very low settings. The surface of the caps was getting warm (not hot) but there where no changes to the picture.

Most of the lines are horizontal. After monitor warms up almost all of the lines are gone.

However picture looks interlaced - very blurry and like it shows only every other line on the screen.

When I press on the top part of the screen - lines do not go away.

I could not find the voltage regulator on the board can you point me to the picture, plz?

Thanks for replies.

[wenter]

Re: HP L2208W vertical and horizontal lines

Little update: I found the voltage regulator - it is almost in the middle of the logic board.
I was going to check the voltages, but before that I decided to hook up the monitor to another computer. As I turned on the computer LCD went white. It does not show any picture now.
I connected it back to the laptop - but still there is no picture on the screen - just white color filled screen
Looks like something really wrong is going on with this monitor.
I will order all capacitors for the power board and logic board from DigiKey tomorrow. Hope it will cure everything.

[jetadm123]

Re: HP L2208W vertical and horizontal lines

Little update: I found the voltage regulator - it is almost in the middle of the logic board.
I was going to check the voltages, but before that I decided to hook up the monitor to another computer. As I turned on the computer LCD went white. It does not show any picture now.
I connected it back to the laptop - but still there is no picture on the screen - just white color filled screen
Looks like something really wrong is going on with this monitor.
I will order all capacitors for the power board and logic board from DigiKey tomorrow. Hope it will cure everything.

A white screen is a possible indication that a fuse has blown on the LCD panel controller board. This board is at the top of the panel and spans the width of the lcd panel. It may be underneath a metal cover or a clear sheet of plastic. The fuse is a surface mount device, marked Fxx and usually located near the flat ribbon cable. Also, go ahead and check the voltage regulator before you check the LCD control panel.