HP L1702 goes on and off

[Lercom]

Hi,

I have a HP L1702 which when I turn it on gives good picture and then goes off after 2 seconds. The power led keeps on lid green. If I then power off and on again same result.
This looks like the problem which many of this forum had with the Dell 173FPB, but the inverter board is completely diffrent.

Anyone has an idea how to repair?

Regards
Lercom

[zandrax]

Re: HP L1702 goes on and off

Post a few detailed photos: perhaps someone can help you.

Zandrax

[olivercan]

Re: HP L1702 goes on and off

HI to all of you I have same problem with me minitor hp 1702.It power up and stay on for few minutes then go off.I push again the power botton come on then 2 second off.the display and picture look ok.please help.THANkiS

[Krankshaft]

Re: HP L1702 goes on and off

Post some pics of the inverter board so that I can get a bearing on what to check.

[olivercan]

Re: HP L1702 goes on and off

here is a picture i took.theres one more thing. when i adjust the contrast to 60 and the brightness to 20 its good for 3-2 hours and then shuts off

[supersabre]

Re: HP L1702 goes on and off

I have the same monitor with the same kind of problem.
The backlights are very marginal, sometimes it works for hours but flickering constantly. And then after a while, the backlight shut down but still has green power led.
I pull the a lcd panel from another 17 monitor, and it works flawlessly(turn it on for 5 days).

If you can find the same panel, then it is fine.
Otherwise, forget about of replacing the backlight. The screen is closely packed with the backlight, it is very difficult to take it apart without damaging the screen and leaving dust and hair inside the panel.

[Krankshaft]

Re: HP L1702 goes on and off

I meant a picture of the inverter / power supply since thats most likely where the problem exists .

[olivercan]

Re: HP L1702 goes on and off

here is a new picture

[Krankshaft]

Re: HP L1702 goes on and off

It seems like not all of the image uploaded I only see half of it.

[olivercan]

Re: HP L1702 goes on and off

ok here it is

[Krankshaft]

Re: HP L1702 goes on and off

The first thing that I would do is replace all of the caps the problem you describe definately sounds like cap problem.

I think the caps on your board are Capxons and their quality is dodgy at best.

While the led remains green and the monitor is plugged into a source shine a flashlight on the LCD do you see an image? If so the main video board is fine.

[supersabre]

Re: HP L1702 goes on and off

The power board is exactly the same as my bad Hp1702. Before i replace the bad light and whole panel,I test every capxon with esr meter. All are good(0.04~0.08), so i don't think the cap is bad.
If you flash a beam of light on the screen and you can see picture on it, then 99% is the faulty backlight.

[olivercan]

Re: HP L1702 goes on and off

thanks for all the help.the moniter is working like a charm
i followed the your suggustions. i replaced the capititors and the back light.
heres a picture on what i changed.

[Krankshaft]

Re: HP L1702 goes on and off

Yet another monitor saved from the landfill.

With a new backlight and replaced caps that monitor will last a long time.

Good job .

[calishe]

Re: HP L1702 goes on and off

olivercan, please post a picture with vga wire connected into main board and say me vga pinouts, I have two problems, VGA pinouts and may be inverter problem (monitor shotdown in 30 minutes)

Thank you


Sorry for my bad english

[ben_re0]

Re: HP L1702 goes on and off

Hi!

i have the same problem with 2 hp l1702 lcd's.
where can i get a new backlight to replace?
how do i replace it?

thanks alot, ben

[yodude010]

Re: HP L1702 goes on and off

hello,

my hp 1702 17" was working fine, but suddenly its condition changed, when i turn it on, green light comes, i can see the image only for 1 or half second and it again disappears and reappears and this thing continues. The picture is fine but the screen keeps on blinking, the light is green, even the computer is turned off, this process continues.

What do you guys prefer me to do?
replace caps or what?

[EGuevarae]

Re: HP L1702 goes on and off

hello,

my hp 1702 17" was working fine, but suddenly its condition changed, when i turn it on, green light comes, i can see the image only for 1 or half second and it again disappears and reappears and this thing continues. The picture is fine but the screen keeps on blinking, the light is green, even the computer is turned off, this process continues.

What do you guys prefer me to do?
replace caps or what?

Inspect them first. It may be a cap problem, or it can be a CCFL. Pics help

[dvorav]

Re: HP L1702 goes on and off

Hi to all,

I got one HP 1702 recently. It has a similar problem. After switching it on, there is picture for lets say 1-2 sec, with outgoing such a scratchy sound. Then it goes off (power LED is not shining).
I measured around 310V on main capacitor. But when disconnecting it, it stays charged for a long time (tents of minutes). So I measured starting resistors. They are two and have 0.6M Ohm in series. It seems good.
The rest of capacitors looks fine, none swollen or so. (They are KZE green ones).

Any ideas what to do?

[EGuevarae]

Re: HP L1702 goes on and off

Hi to all,

I got one HP 1702 recently. It has a similar problem. After switching it on, there is picture for lets say 1-2 sec, with outgoing such a scratchy sound. Then it goes off (power LED is not shining).
I measured around 310V on main capacitor. But when disconnecting it, it stays charged for a long time (tents of minutes). So I measured starting resistors. They are two and have 0.6M Ohm in series. It seems good.
The rest of capacitors looks fine, none swollen or so. (They are KZE green ones).

Any ideas what to do?

Not just the BL, ALL goes off?