Blank screen

It's easy to fix. Replace the power supply board or more commonly called inverter board. I fixed mine, it's easy.

Looks like the monitor is dead. I've just had exactly the same thing happen to mine. Phoned Dell and they're sending out a replacement. Had it two years, but luckily took out extended 3yr warranty so no charge.

Frazz

An extended warrantee is not a bad idea except when they try to sell you differant types of extended warrantee such as a picture tube warrantees not a bad deal as most tvs already have a 2 year warrantee so really your only getting an extra 3 years so idf if the cost is reasonable lets say like under 50 bucks then what the hay i would go for it and lets say like on a refridge or freezer where they extend the warrantee to 5 years Where really most manufacturers alreadsy give ya 5 years on the sealed system but that takes care of labor but an extended warrantee like this will cost about 200 bucks so that woukld be the labor cost if it needed a major repair. Butt some folks are givin ya a rebate now if you take out an extended warrantee and dont use it as my warrantee I got for my fridge is 159.00bucks and if I dont use it in 5 years i get back 85.00 bucks!! So it really depense on how much they charge for the warrantee like if I lived in a remote area I would get an extended warrantee on almost everything I bought. So next time your offered and you say is it worth it?? Spead those paymennts out in your head and just say to yourself thats ids less expensive to pay a little across a time frame then alot all at once!!!

I have had temporary success restarting windows... then I get display again--for me it typically happens during a restart.

The problem could be the power supply as it was for my brother in law's monitor with this issue. The power supply read 12VDC when checked with a voltmeter, but when connected to the monitor. was loading down and cycling causing the flashing green power light on the monitor. You can check the power supply by connecting a 12 volt car parking light bulb to give the power supply a load, The power supply green light extinguished and failed to light the 12 volt car bulb when connected. The power supply is rated at 12 volts at 4 amps and another power supply rated 12 volts at 2 amps would power the light bulb and monitor when connected. Hope this helps and have a great day!

replace the caps on the psu. c215, c211, c213, c214, c216, c212. they are 470uf 25v. It comes apart very easy and the caps are in a good position for removal.

This problem is very often caused by dry electrolytic capacitors on the inverter board. If you have some skill with soldering you could try to change them. When buying new ones ask for LOW-ESR capacitors for switching mode power supplies (SMPS) and 105°C, they are a little bit more expensive than normal electrolytic capacitors, but are designed for this aplications so they lasts more. Normal el. caps will also works fine so when you cannot buy LOW-ESR for SMPS use normal ones.

bad inverter

Just a tipp.
I have also a 447XS 17" monitor. I have the same problem (the monitor works a lot and then the picture goes away, but the power led is on).
The problem is the poor soldering (broken soldering points) at the high voltage transformer legs. Just a little soldering and the monitor works great again.
Warning! Be cautious at soldering! The components contains high voltage also at deactivated state!!!

Sorry for the bad english.

Hey, guys, my power surged and my monitor power button flashes green and the screen is blank. When plugged in, I listen into the back, I hear  click and a beep with every flash. I'm just saying, if you guys hear this, it's definately a problem in the monitor and not in the computer, because mine works well with an older monitor. The power source probably died inside, meh.