Najataagihe

Thus, the suspected spike.



Different circuit components have different tolerances to “dirty power”.

They may be on the way out, too.

Ain’t that lovely?

Najataagihe

It’s not the monitor, it’s the circuit board components IN the monitor.

Najataagihe

Spikes hit 25,000 volts.

Or more.

Najataagihe

If only this were true.

DirtFarmer Loc: Escaped from the NYC area, back to MA

We had weird power problems once. It turned out that the neutral got disconnected at the pole. We had a standard two phase 220/110 system so when something got turned on it had some voltage applied between 220 and 0 depending on what was connected on the other phase. Didn't fry anything except a couple of incandescent bulbs. But the power company came out right away when I told them what it was.

Robertl594 Loc: Bloomfield Hills, Michigan and Nantucket

I have an electrician coming out this week. I would have thought that since the AC is being converted by the adapter, it would somewhat prevent that from passing to the monitor. Only guessing though.

Robertl594 Loc: Bloomfield Hills, Michigan and Nantucket

I agree!

Najataagihe

Nope!

That brick is just a transformer/rectifier.


F’rinstance: 120 VAC in = 12 VDC out…..usually.

BUT, 12000VAC in = 1200 VDC out, until that brick becomes an expensive fuse.

By that time, your circuits are toast.

Gotcha.


Fortunately, these spikes will only last milliseconds, but get a longer one or, more usually, dozens or hundreds all at once and it is open season on electronics.




Don’t confuse house voltage with spike voltage.

Robertl594 Loc: Bloomfield Hills, Michigan and Nantucket

Thank you

chrissybabe Loc: New Zealand

Probably faulty capacitors in the monitors. These are the usual cause of monitor failures. I didn't see any mention of operating or environment temperatures. It is heat that causes capacitors to fail. I would add a good mains power filter before the monitors just to be safe.
Now secondly don't forget about the laws of chance. Most owners of failed monitors only have one go down. But there will a very small percentage of times when two will fail and you may have been 'lucky'! At 5 and 6 years old consider them consumables.

Robertl594 Loc: Bloomfield Hills, Michigan and Nantucket

Yes, very possibly. Thank you.

GLSmith Loc: Tampa, Fl

There are a few possibilities not commonly spoken about. I speak with 8 years experience in repairing of computer monitors. All monitors have a low volt and also a separate high volt power supply Typically these are mass produced overseas. There are numerous bad batches that often come out. I got stuck one time with replacing the low volt power supplies on a new group of monitors that had been installed for the government....about 650 monitors....by the company asking for them back, you may want to do a bit of research and research on Google if you can find out about any recalls for the specific model you have or try & find a schematic for the monitor, identify the low volt & high volt ps part numbers & see if there has been a recall...Monitor companies will stay quiet a lot of times as they want to sell new one. The other strong possibility is the "Power Brick", there have been a lot of issues with them in the past & they may have taken a power surge & now overheat and shut power off to the monitor. To see if you have power issues to the outlet used, you can try running in a heavy duty extension cord from another outlet in a different room & plug in the power bricks and see what happens.

Robertl594 Loc: Bloomfield Hills, Michigan and Nantucket

Great information. Thank you. I did try the extension cord, as well as a different circuit in a different room. Same result on the Samsung monitor. Will turn on, but will eventually turn off again. Do you think it’s the brick?

I have ordered a new monitor as I need one. My concern is that I experience the same thing again with the new one. Do you think a surge protector, one better than I have, will protect the new one?
Thanks again

redtooth

Sounds like you are on 220 volts not 110 at that socket . Try another female outlet .

flferg Loc: Driftwood, TX

1. Both your monitors have converters to reduce the line voltage from 100-240 volts ac to about 19 volts dc.
2. The common element seems to be your surge protector or what you call a power brick
3. Do not plug either of the monitors into your brick. Do not plug a new monitor into this brick.
4. Plug the monitors into a regular outlet and see if they run ok. If they run ok and don't shut off you need a new brick.

I looked on Amazon for AC adapters for your monitors and a description of what they typically provide follows below. Based on the features designed into the adapters I would guess you have a brick problem and not monitor problems. The odds of two monitors developing the same problem after operating properly for years is almost nil. Now if you look at what is common it is the brick and while it is possible the brick may have damaged your monitors that seems unlikely since they operate ok after cooling off. BTW, I am a retired EE with years of experience with issues like this and you can email me at lonferguson1@gmail.com if you need an explanation of how to do any of the tests I mentioned above.

Typical AC Adapter Description
World Wide Input Voltage 100-240VAC 50/60Hz. OVP, OCP, SCP Protection (OVP: Over Voltage output Protection. OCP: Over Current output Protection. SCP: Short Circuit output Protection). Tested Units. In Great Working Condition. UpBright 30 days money back guarantee. 1 full year service warranty.
UpBright New Global 19V AC / DC Adapter Compatible with LG Electronics 34UC97 34UC97-S LCAP31 EAY62949001 34YM95C 45UM94-P UM95 34UM95C 34UM95C-P Curved Ultrawide 27UD88 27UD88-W 27UK850 27UK850-W 4K UHD LED Monitor 19VDC DC19V 19.0V 19 Volts Power Supply Cord Cable PS Charger Mains PSU