General discussion


Screen flashes during switch on and bootup

By RobFJ ·
I'm running windows 7 with dual monitors.

When I switch on in the morning one of the monitors immediately starts to flash (about once a second) and this will continue through log on and start-up. Eventually I end up with one monitor showing a stable image and the other still flashing.

If I power off (ie not an orderly shut down) and on, go into start up options and choose the last known good configuration, then the screen still flashes all the way through to what must be the last part of the start-up when the flashing stops and both monitors show stable images.

I've shut down and restarted during the day with no problems. The problem started about a week ago during which time there have been a few windows updates and restore points set. So I guess the last known good configuration is changing but the problem continues.

Any advice on how to resolve the problem would be appreciated

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if one monitor seems ok

by PurpleSkys In reply to Screen flashes during swi ...

then my guess would be that monitor is going. Maybe try connecting that monitor to another computer to see if it does the same thing.

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Monitors are probably OK but problem is still there

by RobFJ In reply to if one monitor seems ok

I switched the cables around between the two monitors and then the other one flashes; I also switched the cables round. So it suggests it is in the pc. What I can't understand is why it happens at the very early stages of boot up (well before windows starts up) and then is rectified when, I assume the windows drivers are finally loaded.

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bad cables? NT

by PurpleSkys In reply to Monitors are probably OK ...
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Flashing only happens after long switch off

by RobFJ In reply to bad cables? NT

Just isolated the fact this flashing only happens in the morning - or perhaps after a long switch off. (I rebooted last thing at night with no problems and did an orderly shut down - no problems on 3 occasions I tried it. I rebooted first thing the following morning and the problem was there.)

I swapped the CMOS battery to rule that out as a possible problem - but the flashing is still there.

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if one monitor does it

by PurpleSkys In reply to Flashing only happens aft ...

and the other one doesn't, it would suggest to me that it's the monitor. Would it be possible to hook up either another monitor with a different cable or hook up the flashing monitor with it's cable to another computer). Leaving it shut down at night and then booting in the morning. I personally think it's either a bad cable or a bad monitor, if it were the pc, both monitors would be flashing I believe.

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Flashing Monitor - fault finally found :)

by RobFJ In reply to Screen flashes during swi ...

Thanks all. It was a faulty capacitor on the PSU of the monitor. Eventually it got worse which helped trace it.

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good to hear

by PurpleSkys In reply to Flashing Monitor - fault ...

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