Is electric charge in new TV body normal?

[Alpha0mega]

I am not sure if “Power Supplies” or this section is the right one for this post, but since it’s a weird electricity issue I decided to post it here.

This is why I noticed the issue:
I recently bought a Sony XBR43X800D (43", 4K) to use as a monitor. The day I got it I set it up, got the picture how I wanted it and did the firmware update. Watched stuff on it for a few hours, with about 1 hour of standby, a couple of times, in between. Then put it on standby before going to sleep.

Next morning I tried turning it on with the remote and nothing happened. Unplugging and replugging did nothing. So I unplugged it and left it for a couple of minutes, then plugged back in and it booted. Android showed the message "optimizing apps". After this was over, I set the input to HDMI 2, and in a few seconds, the TV started squealing loudly with horizontal green lines all over the screen, and then turned off.

Unplugging and leaving it for a few minutes did nothing, so I left it unplugged for 10-15 minutes, and then plugged back in. It started, after being on for a 2-3 minutes this time it did the same, squeal and lines followed by turning off.

Then, if I left it unplugged for an hour or so, it would start, but sometimes it would boot multiple times, or crash without warning after a few minutes. And then it stopped turning on completely, even if left overnight.

The power issue:
While I was troubleshooting the TV, trying out different HDMI cables etc., in order to press the TV’s power button (located behind its left edge), I ran my finger along the rear bezels, when I felt a very light current. It felt like the bezel, which is smooth metal, was lightly textured or rubberized. To confirm I wasn’t imagining it, I pulled the plug, and the feeling went away, with the bezel feeling like smooth metal.

- The bezel charge would be present only if HDMI wasn’t connected to my computer (GTX 970). With HDMI connected it went away.

- The charge would be present only if connected to the mains. I tried running the TV off only the UPS backup, and the charge wasn’t there.

- The TV plug is two pronged, not three.

- The grounding to my mains socket is working. I checked, but to be sure I redid it too. Instead of connecting to the house earth (inside the walls), I bought a new earth wire and ran it directly from my socket to the grounding conductor (the wire going into the buried electrode). The charge was still present.

- This isn’t ESD, since it appears the moment the TV is plugged into the mains, and is continuous.

Keep in mind that the charge was very mild, not painful at all. I am very sensitive to electrical charge and it was mild for me, so I doubt that most people would even feel it.

So, is there being a very mild charge in the TV body normal?
Could that be the cause of the TV malfunction?
Connecting it via HDMI to the computer seems to ground the TV, but would it harm the GPU/computer?

I am getting a new piece soon-ish, would appreciate any advice or reassurance.

 

[[DHT]Osiris]

An actual charge is absolutely not normal. I'd verify that you weren't feeling some kind of odd vibration/enhanced coil whine though, and that it was indeed a charge (if you have a multi meter, that'd do it). Any measure of charge on the body means something's shorting/not grounding properly, and is probably the cause if the issues you're having. I'd RMA that thing immediately, or potentially look at a different model. Something that severe could be indicative of a manufacturing problem.

 

[William Gaatjes]

Well, it could be that one of the y capacitors went/ is bad. Causing some weird issue. Or not.
These capacitors filter out common mode noise. They are placed between the mains voltage and the chassis / ground connection.
Does the mains input have a 3 terminal mains input ? With a Live terminal, a neutral terminal and a ground terminal ?

http://www.elt-blog.com/en/la-seguridad-siempre-lo-primero-condensadores-de-seguridad/

The feeling you describe, sensing the charge. I know it as well when touching the metal chassis very lightly. But i need an electrical contact. But i sometimes only sense it with devices that need to be grounded for proper functioning but are not grounded. It does not have to mean something is wrong.


I would RMA it as well.

 

[Alpha0mega]

The TV is going back. Should get another piece in around 2 weeks. I guess the current was because it wasn't being grounded (not a 3 prong plug), and was using the computer to ground itself, via the HDMI cable.

 

[bryanl]

- The bezel charge would be present only if HDMI wasn’t connected to my computer (GTX 970). With HDMI connected it went away.

- The charge would be present only if connected to the mains. I tried running the TV off only the UPS backup, and the charge wasn’t there.

- The TV plug is two pronged, not three.

- The grounding to my mains socket is working. I checked, but to be sure I redid it too. Instead of connecting to the house earth (inside the walls), I bought a new earth wire and ran it directly from my socket to the grounding conductor (the wire going into the buried electrode). The charge was still present.

There are RF filter capacitors across line & case ground and neutral & case ground (with 240V the second would be between ground and the other line), and when case ground isn't earthed, it floats to half the AC voltage because each capacitor drops half the voltage between line and neutral or between the two neutrals. The capacitance is very low to limit the current to harmless levels. That voltage disappears when you plug in the HDMI cable because the cable's ground connects the TV's ground to earth via the ground of the computer or tuner box, meaning they must have 3-wire power cords.

 

[William Gaatjes]

Indeed. That is why the case should be grounded. But i do not feel a charge when touching the blank metal parts of the computer case.
To be honest, my whole pc system ground is floating.
I have a water pipe from the central heating nearby, but i do not think it is a good idea to ground it that way. I do not know why, but i have a bad feeling about it. I did check with a multimeter, the ground /earth terminal from the 230V socket is connected to the water pipes.

 

[bryanl]

An actual charge is absolutely normal with a 2-prong connection, if it's only through the two Y-capacitors, which apply half the AC voltage to the case ground.

 

[technisol]

Mystery voltage sure sounds like leakage... With "modern" non-isolated 5Vdc USB power bricks you can measure 50-60vdc, albeit at hopefully very low currents, between the case of many metal enclosed PCs/tablets, etc. back to earth ground and/or neutral.

But it sounds like you may have something more than that going on, and/or that you are feeding in a signal that does not in some way match the expected input in terms of scan frequency, etc. from the way the device reacted... Perhaps it was just an internal power supply dying in a terribly graceless manner -the kind of way that usually results in blown electronics due to too high a voltage or voltages being applied to internal components from a blown regulation system, etc.

Send it back and if really curious call their tech support first and see if you can find anyone that actually has the tech background to understand what you're describing or what components may have gone. In this modern world, I imagine you'll merely get a "please ship it back and we'll take endless months to fix it under warranty" response... Unh, uh! Make 'em take it back and if they try that crap insist on a refund and buy a better brand rather than accepting an exchange as they will be just as clueless when the replacement exhibits the same poor behavior several days or possibly minutes or hours after your warranty expires should the replacement device survive the the initial 24 hour burn-in.