Chosen Solution

I have a BenQ 27 inch monitor. I hook the monitor to my laptop to have a larger display. It was working fine for a year. The issue: Recently the monitor shuts off every 1~2 minutes, and after another 1~2 minutes turns back on. This cycle goes over and over. A few observations are as follows. During the turn off, its green power button also turns off (the power button will not become orange). That means, it is not just the display that goes off, but it seems the whole power of monitor goes off. I suspect this is a power issue.During the time when the monitor is on, there is no problem with the display itself. I doubt it this is the issue with the graphic card of a driver related issue.Changing the power cord, or power outlet does not help. It is also connected firmly.Changing the cords of either VGA, HDMI, Display port and their connectors does not affect the issue.Using a different laptop/PC or operating system connected to the monitor does not affect this issue. Also, my laptop works fine with other monitors. My attempt to fix it: I suspected this might be a bad capacitor on the power board. I neither found a bulged capacitor by a visual inspection, nor there was a smell or noise from capacitors. However, I ordered a couple of capacitors online with the same specs, and replaced some of them on the power board. The issue still persists. Question: I do not think I am able to find which component on the board is causing the issue. So, I want to just order a whole board from a vendor. Before spending time and money on ordering a board, I want to (almost) make sure if it is the power board issue at all, or maybe the main board (graphic board) issue? Thanks.

@siasunny from your description of this it most certainly sounds like a bad power supply. The only way to make sure it is would be by having a schematic and measuring outputs etc. Since those are not readily available for further troubleshooting, I’d go and purchase a power board and try it out. Purchase from somewhere that has a good return policy just in case it is not.

I had this exact same problem and I sorted it immediately by changing the refresh rate down in the advanced section of the display extender screen config. Type Display and choose extend display. Select the corrected screen then go to advanced. Change the refresh rate. Bingo, worked straightaway.

i don’t think so. first thing: power supply is not directly connected to your monitor. Second thing is if bad powersupply shut down graphic it would also shut down the whole system, as this would be a system failure. PSU must be a super fckin creative to shuts only graphic card for few minutes. To be able to do that it basically would need an option like that builded itself in it. And since nobody cares about that they just would bring up an system failure instead. And actually if you overload them they mostly would just burn something up. If they were branded like be quiet!, most probable that they would burn itself, but if it’s a cheap crap from ebay or amazon, they will burn a part of your pc. Besides there are many more “events” that would occur before it would even happen with bad power supply. I had similair problem and i just needed to clean and cool off monitor. Try to point fan on it and i think you will have an easy solution. Besides i can’t have a bad power supply. my cpu uses 80w max peak and my graphic 200. my psu is 600w gold from be quiet! system power. 300w going on what? Keyboard? Mouse? i don’t think so. Besides my second screen doesn’t even flintch during these “shutting off” moments. And tbh they are close and he creates a lot of heat.

I changed the power cable, I have open it, test capacitors, test power board, nothing! I don’t know if anyone have this problem still, but I think I found solution.

  1. Turn off the monitor
  2. Press and hold menu button and power on the monitor
  3. you will be in BenQ Service Page
  4. navigate to timer reset
  5. click OK and confirm in new dialog box
  6. turn off the monitor and on again. Problem solved.

I’ve had this issue before and solved it by taking the monitor apart and cleaning the buttons with alcohol. Take the button board and squeeze alcohol on them while pressing the buttons over and over to help wash them out. Then leave it for 24hrs to be 100% all the alcohol evaporated. The inner button getting dirty can cause a tiny short making it turn on and off or even eventually get stuck off. Be liberal and push the buttons a lot, especially the power button. You’re trying to wash stuff out of the enclosed switch.

Mine was turning on and off for awhile before getting stuck off. I figured at that point I couldn’t make it worse so gave it a shot and saved me from having to buy a new monitor.

I was having the same problem with a 6 foot long HDMI cable.. replace this with a smaller 3’ newer HDMI cable.. no more blank-outs for now..

I found the power board with components burned in a specific area on it. I ‘am buying a new one on the net.