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Second monitor dark

One of our employee's has dual screen. One of her monitors has suddenly become very dark, you can see windows on it but its too dark to read any text or see where the mouse is. The other monitor is fine.

This happened first a couple of months ago. I thought it was an old monitor problem, switching the monitor seemed to solve it.

Then last week it happened again. I switched the vga cables over to confirm it wasn't the monitor at fault so I changed the graphics card. This again seemed to solve the problem.

Then this morning the employee turned on her pc to find the problem had reappeared. Having replaced the monitor and graphics card already (and drivers since new graphics card required new drivers) I don't know what else it could be.

Not sure if this helps but I did find an error in the system error log for last night...
Event Type:      Error
Event Source:      ati2mtag
Event Category:      DAL
Event ID:      43029
Date:            07/04/2009
Time:            16:49:53
User:            N/A
Computer:      XP473
Description:
Display is not active
Data:
0000: 00 00 00 00 01 00 5a 00 ......Z.
0008: 2a 00 00 00 15 a8 00 c0 *....¨.À
0010: 00 00 00 00 00 00 00 00 ........
0018: 00 00 00 00 00 00 00 00 ........
0020: 00 00 00 00 00 00 00 00 ........

Your help would be much appreciated, thankyou in advance.

HP dx2200M
Win XP Pro v.2002 SP3
Pent4 3.00 GHz, 512MB RAM
Current graphics card: ATI Radeon HD 2600 Pro, driver version 8.493.0.0

exclamationsoft

Just a shot in the dark (pun intended), but it could be that the video card is underpowered. These days, power sucking video cards can require huge amounts of wattage.
Using this online calculator: http://www.journeysystems.com/psu.php, it appears that you need at least 200 Watts - I just picked what you list above. 200W is quite low, but I don't know all the components installed, so you should try it for yourself.
Hope this helps.

defaqto

ASKER

Wouldn't that affect both the two monitors? Only one is affected. And the single dark screen is the only symptom. It may not be the speediest pc but the performance is ok.

exclamationsoft

Are the monitors CRTs or LCDs?
I have seen, from time to time, certain LCD monitors go haywire after coming out of sleep mode. The only way to get it back to normal is a cold boot: shutdown, power off, wait, power on.
Does the computer go into sleep mode?
Does a cold boot help?
Are both monitors plugged into a single power strip? UPS?
Just throwing out a few things to answer and think about.

Dangle79

Are there hotkeys assigned in the driver for adjusting certain video options (brightness/contrast/etc)? I've seen before where a user will accidentally hit one of these key combinations and change their resolution, rotate the display 45 degrees and all variations of things. It may be some part of an occasional work flow.

This could be the case if the problem is only related to the one output. In this case the add-in card. (assuming the primary is on-board) Could test this by reversing the connections and see if the problem follows the add-in card.

ASKER CERTIFIED SOLUTION

Callandor

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defaqto

ASKER

exclamationsoft: The monitors are LCDs.
A cold boot didn't seem to make a difference. The PC was turned off overnight and when turned on this morning the problem remained. Although then turning monitor off and on again quickly brought it back. This problem seems to be quite intermittent, the screens were working at the end of the day yesterday after various updates/restarts but then not this morning after being switched off. Our pc's don't use sleep mode. Both monitors are plugged into the same extension lead. No UPS.

Dangle79: Both monitors plug into the same expansion card.

Callandor: We had PAT testers only 4 weeks ago so I'm hoping they tested that outlet. But your idea about power is interesting. I've just tried moving the monitor power plug to a different socket and it has visibly brightened. I don't know if it will stay that way so I'm going to give it a few hours to find out.

Thanks for all your help guys. I'll let you know when I have further results.

defaqto

ASKER

Swapping to a different plug socket seems to have worked since there's been no recurrence of the problem in the last 4 hours. Will award points to Callandor if all is still well tomorrow. Thank you all.

defaqto

ASKER

I'm closing this question now because I ended up replacing the monitor. Although I feel fairly certain the problem may return in the next couple of months. This response fits my solution better than the others, though I don't believe I've found the underlying cause yet. Thankyou all for your help.