Monitor dead: is the fuse broken?

[seneka99]

Hello everyone.

It is my first discussion on the forum and I hope I have chosen the right section. My monitor no longer turns on.

I'll explain the problem. 3 weeks ago I found a 234cl philips brilliance that my father no longer used and was covered by dust. I mounted it and it went perfectly for the first two weeks. last week it started to give problems, not turning on immediately when the pc was started, but only after a couple of minutes. I didn't pay particular attention to it. Last night, the PC was on standby, I unlocked it and the monitor showed no signs of life. To be powered it was powered, with a led light on. I waited a couple of minutes as usual and it started to show the monitor startup writing, intermittently, as if it turned on and off. Then the "no video input" notification appeared and turned off. Not knowing what to think, I turned the PC off manually and postponed the problem to this morning. Here's the trouble. Today even the monitor LED does not turn on. Completely dead. I searched the web a bit and realized it could be a power supply problem. I found out I used the wrong power supply! It belonged to another monitor: it delivers 19 volts and 2.1 amps, compared to the 12V and 4 A that my monitor required. I therefore think that this higher voltage has broken something. Could it be simply the fuse? Do you suggest me to buy the correct power supply transformer? I wouldn't want to throw the display away and, if it is an easily solvable problem, I would try to do it myself. What do you think?

 

[Regeneration]

It's dead. Doesn't worth the time or money to fix. Asus 144hz monitor lineup is superb and the 24-inch model (VG248) is cheap.

 

[Ahhzz]

Here's a couple of things about voltage and amperage. Systems have a tolerance in what they accept and use. Too much amperage from a PS really doesn't hurt the circuit much, as it won't draw more than it needs to an extent. You can't plug a 20A power line to a 800mA calculator and not expect smoke. The same with voltage, for slightly different reasons. The components in the circuit will just take a little more voltage off all the way around to even it out across all of them, and a slight over-voltage won't affect most devices. Again, 60 v to a 5 v fan: bad idea, smoke.

However, under current and under voltage are much worse. Give a system too little voltage, and it likely won't even turn on, as there's not enough to "forward bias" (turn on) diodes in the system. But give it too little current? It will do it's best to run things at a reduced rate, allocating as best it can across everything. If you've ever seen a "brown out", that's basically what happens: not enough current available for all the buildings/devices due to a failure upstream. Too little current is horrible for electronic components. Transformers burn out, Things Go Badly.

Basically, you probably could have been semi-ok with giving 19v to the 12v device. But undercurrenting by half what it needed? You starved it, and even if you manage to get it to come back to life with the correct power supply (which I seriously doubt), you've made a huge dent in it's longevity. It won't last long at all. You gave it enough voltage to ensure everything have enough to "turn on", but then didn't give enough current to keep them going. Kind of like slapping someone until they wake up every time they fall asleep for 2 weeks, but not giving them more than a slice of bread every day. Sure, you woke them up, but they can't function.

With under-current on the device, there's no way you could reasonably troubleshoot what components have failed/were damaged without a schematic, and taking most of them out of the circuit to test one at a time. I've several years electronic troubleshooting, and even in my prime, I'd never have tried to figure out what might have failed in that scenario.

If you have the schematic, and days of time with a good fluke/multimeter, have at it, and make sure to update us on your progress. If not, I'm afraid I'd be looking for a replacement monitor. I could recommend Planar monitors, as they have a 3-year advanced exchange warranty

Good luck!

 

[Regeneration]

Finding and replacing a power supply board for that monitor isn't difficult.

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But when something like this happen, its possible that other parts were damaged too.