I have two monitors, both of which were working prior to a recent move, and now neither of them show a (full) signal from the computers I've tried them on. They turn on, the menu ctrls work on one of them, but they say "no signal", or "check cable" or are just on but a black or greyish screen (other than brief flashes of color or a cursor, see below).

It's not a computer issue, because another monitor works fine on my two test computers. I've also tried seating the cords better, changing the inputs, nothing. Well, at one point for a few seconds I saw a cursor and a flash of blue but then it went to this dark grey (not quite black) state and one of them said "NO SIGNAL".

I'm so puzzled because it is BOTH of my old monitors at once, in exactly the same way. My only wild guesses as to what could be happening or happened is:

  • Somehow "trauma" from the move broke them both just in this way. But they power on and at least one shows the menu controls, so it strikes me as very odd that slight jostling or very mild heat (moved May 1; temp was prob in the 60s-70s) would knock them both out in the exact same way--particularly in a way that just affects receiving inputs, not the actual display.
  • I am maybe using the wrong power cord on both...but it fits and has no box, and they both turn on and display menu settings, etc., so I can't imagine it matters in this case.

Is there some other way to figure out what happened? They are like 21" or so HP and Coby monitors and worked just perfectly prior to the move, so this is pretty frustrating and I'm wondering whether I can resurrect them.


EDIT: Solved. Somehow, by trying my one monitor on a laptop and toggling the screen output and selecting a different "source" on the monitor, it eventually hit on the right combo and works now. Haven't tried the other monitor, but this is good enough for now. I knew they couldn't have both died in the same way.


Can the signal cables be swapped or are those models with no detachable cabling? If you can swap them try different cables. Thy using the one from the monitor NOT showing "No signal" message.

Does the monitor NOT showing the "no Signal" message displays picture for several seconds after powering up? And then it's blank screen (like when turned off) with power LED on? If yes, you're out of luck - one or more capacitors in the power inverter failed and needs to be replaced. If you know your way around electronic and if you have access to soldering equipment you can try fix it yourself. It is very common failure among older LCDs, unfortunately. There are videos on youtube how to fix that, if you're interested. IIRC it's about $10-15 for a handful of capacitors and then you can even have side business reanimating old screens.

As for the other screen - if cable is non-detachable, then try moving it when all is powered up and properly connected. if you will notice even flashes of picture displayed, then it may be that cable got damaged while moving (i.e. pulled accidentally way to much), or plain broken (can happen if bent too much too long). Again, may be worthwile to look under the back cover and see if all solders are fine...

  • While you were answering this, I tried again with a laptop, toggling the output to a 2nd monitor, and the "Source" button on one of the two "dead" laptops and lo! it displayed the screen! So not sure why the Source button didn't work the first time I tried all this. I'll vote you as solving it though and the question could be closed. Thank you. – tripperjack Jul 14 '15 at 18:44

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