[SOLVED] Desk Fan and Monitor Black Screen

[Wolfinch]

I have 19" LED Samsung monitor, and something weird happen everytime I turn off my desk fan.

View: https://youtu.be/zo4L9so7D8o


The monitor turned black in few seconds everytime I switch the fan off (Through extension switch). But this NOT happen when I turn off directly from fan switch (switch in fan's body).

Question is, why this can happen? Can it harm my desktop/monitor? NOTE: There's no voltage drop, I have volt meter, and all normal.

 

[hotaru.hino]

There may be brief pulse of EMI that's enough to corrupt the video signal.

 

[Wolfinch]

There may be brief pulse of EMI that's enough to corrupt the video signal.

What is EMI? Magnetic field? Is it safe? Can it harm electronics near it?

 

[hotaru.hino]

What is EMI? Magnetic field? Is it safe? Can it harm electronics near it?

EMI = Electromagnetic interference.

Oversimplifying things, under certain conditions, an electrically conductive wire can emit a random radio wave. If it's received on wires that carry power, this isn't really a problem (usually there's something to filter it out). However, if it's received on wires that carry data, it can morph the signal in a way that makes it look like garbage

For the most part it's harmless in the sense that your components aren't going to blow up.

 

[Satan-IR]

Is the monitor conntected to PC via HDMI cable? Have you tried with another cable?

 

[Wolfinch]

EMI = Electromagnetic interference.

Oversimplifying things, under certain conditions, an electrically conductive wire can emit a random radio wave. If it's received on wires that carry power, this isn't really a problem (usually there's something to filter it out). However, if it's received on wires that carry data, it can morph the signal in a way that makes it look like garbage

For the most part it's harmless in the sense that your components aren't going to blow up.

Thanks, and how about external drive? This condition cant harm my external drive right?

One more question, why it only happen in that power hub? When I use default fan switch OR change to other power hub, nothing weird happen

Is the monitor conntected to PC via HDMI cable? Have you tried with another cable?

It's old VGA cable, and I use converter HDMI to VGA

 

[Satan-IR]

Sometimes depending on building wiring there's a slight change in voltage when switches are flipped (ON/OFF) and not so good quality cables (seen this with HDMI mostly) or adapters lose signal for a fraction of or a second.

One more question, why it only happen in that power hub? When I use default fan switch OR change to other power hub, nothing weird happen

This "other power hub" is connected to same circuit as the monitor? Probably not. Or is it conencted to another wall socket or in another room?

If there other different adapter and cable avilable you can try those and see if that resolves it. Also see if changin monitor power saving settings makes any change.

 

[Wolfinch]

This "other power hub" is connected to same circuit as the monitor? Probably not. Or is it conencted to another wall socket or in another room?

I don't know how to explain in words, so I make new video about this..

View: https://youtu.be/a3yo_9VREIA

 

[Satan-IR]

Maybe that first extension that is next to monitor and the case (the black cable and plug?) which is feeding the other extension with the fan at the end and is not good too, or maybe that switch. Can you test with another extension? Does this one you use have surge protection of any kind or is just an extension for switches for every socket/outlet?

Did you try turning power saving features if the monitor has any?

Also as said above, again that might be because of a slight change in voltage and current which interference on the display cable signal. If available try with a different VGA cable and another HDMI (to VGA?) adapter, maybe an active one.

I don't think that would hurt your external drive as it's a USB hard disk? If so that is connected to the PC USB port which is being fed by the PSU and motherboard VRM and there's filters and the voltages are clean and OK.

If that black cable and plug is the monitor and turning the inductive load (fan) turns it off and on because of changes in voltage and so it might hurt the monitor. So if you can't change the extensions and the electrical arrangement then maybe be better to connect the fan like how you did n video that doesn't turn the monitor ON/OFF.

 

[Wolfinch]

Can you test with another extension? Does this one you use have surge protection of any kind or is just an extension for switches for every socket/outlet?

I dont think it have such feature. And I tried to change with another extension, and yes it still happen.

Did you try turning power saving features if the monitor has any?

I can't find that feature in my monitor

If available try with a different VGA cable and another HDMI (to VGA?) adapter, maybe an active one.

Not possible, it's the only one

So if you can't change the extensions and the electrical arrangement then maybe be better to connect the fan like how you did n video that doesn't turn the monitor ON/OFF.

Yes, I think you're right. There's no other option. Thanks for your answers.