Electrical problem fried our Joey, TV, and blu-ray

[JimD]

I was replacing some light switches yesterday (wrong color) and didn't disconnect the circuit. On the last switch, I think I may have let the power lead touch the adjacent switch's front metal. The switches are not grounded but the box is metal and apparently it is grounded. So when you screw the switch down, that would ground it. I am not 100% sure that is what happened but it makes the most sense. At about the same time, my wife yelled that the Joey (dish device for extra TVs) blew up. I think I delayed going to see it to connect the hot wire to the switch. What I remember for sure is when I came back all that was left was putting the switch into the box. What may have happened is the two front plates of the switches touched, one grounded and the other not. But why would that spark? It wasn't big time stuff at the switches, just a black mark on the one switch about where the bottom screw goes. No significant pit in the metal.

LOML said the Joey threw up a major spark and started smoking. It was plugged into what I thought was a surge suppressor but may be just a power strip. Everything plugged into that strip doesn't work. A 42 inch plasma TV, a almost new blu-ray/streaming device, the Joey (which has a transformer at the strip plus little cord presumable low voltage) and a cheap clock. No breaker tripped.

There are two circuits in the switch box neither of which is on the same breaker as the bedroom where the Joey was. One of the circuits in the box had the hopper and another TV connected to it. They are on another power strip that might be a surge surpressor. Neither the outlet with the hopper in the great room or the bedroom outlet is grounded. They have three plug outlets but our tester says they are ungrounded.

So was this a weird coincidence or did the short at the switch, on a different circuit, cause the Joey to blow and all the other stuff too? Did the Joey catastrophically fail on its own and damage the TV and blu ray through the HDMI circuit?

[Slik Geek]

I'll hazard a guess. The details of your setup are not entirely clear, but given the following clues: Live circuit, multiple switches, no breaker tripped, different circuits, ungrounded outlets.

If a hot wire connected to phase A managed to touch the ground-wire-connected switch box (such as through contact with the body of switch #2 which in turn was making contact via the mounting ear with the box metal), and the TV and other devices were powered from phase B, and the ground connection from the switch box was connected to the outlet ground at the TV but not to earth, the following may occur:

120VAC from phase A is connected to the intended earth ground of the TV (I'm assuming that the TV has a grounded plug). Now, instead of the expected 120VAC between the TV's hot wire and the ground, there is 240VAC (two opposing phases). Various circuits in the TV and the other failed devices have a connection between the earth ground and the circuitry. But now that ground connection is hot, so high voltage causes currents to flow into sensitive circuitry - but the circuit impedance is high enough to not blow a 15A or 20A breaker, but far too high for the sensitive circuit to withstand. Poof goes the TV and the connected Blue Ray.

Lil' old Joey has the misfortune of an HDMI cable with a grounded shield connection to the TV, so Joey gets high voltage and the resulting current where he doesn't expect it, causing several amps to flow resulting in a bright flash, but not enough current to blow the breaker.

The clock? I can't explain its failure unless it for some reason has a grounded plug or some other connection to one of the failed devices.

[JimD]

Thanks for the thoughts. But the switch that shorted was grounded but the tester says the TV that was ruined was not. The short caused a voltage spike but nothing else was damaged and they were closer electrically to the spike. I don't see how it went to the ground of the TV when it wasn't connected.

[capncarl]

Your 110 common wire became your other leg for your new 220 volt appliance cooking machine you built! 220 does not require a common or ground to operate. It would have probably fried anything else you had plugged into that curcit.

[vaking]

Electrical outlet has 3 wires: Phase (hot), neutral and ground. Grounding wire normally is not supposed to carry any current - it is just for safety. Neutral wire is expected to be connected to the ground at the electrical distribution panel. Hot and Neutral wires are supposed to carry all current in the circuit. Now imagine that your neutral wire in one of the circuits have a poor connection to the ground. You will have high resistance in that circuit and lights for instance will be dim. But electronic devices also have high resistance and they might still operate on such circuit, so you might not notice the problem if all devices connected to that circuit are electronics with high resistance/impedance. When you were working on the switch - you probably had 2 separate circuits in the same junction box. You accidentally connected neutral wire of one circuit (the one with poor ground connection) to the phase (hot) wire of another circuit. Because neutral is poorly connected to ground - the resistance was too big to trip circuit breaker. As a result you got 2 different phases connected to 2 wires in the circuit that has lots of electronics plugged in. 2 Different phases give you 240 Volts instead of 120Volts, so high voltage fried all that electronics.

[JimD]

A major problem with the 220V therories is the fact that the breakers for all these circuits come off the same hot bar in the breaker box. So it wasn't a different leg going to ground and accidentally back out the neutral, it was the same hot leg making the voltage 110 at most.

Other issues with that theory is the lack of damage to other devices. We have a fanlight that was on that is on the same breaker as the TV. It isn't as sensitive to surges but can't take 220v. It is fine.

I'm struggling to see how the brief, mild short on another circuit on the same hot leg got the Joey. The surge wouldn't have been much if any worse than the well pump starting. But I appreciate your thoughts.

Jim

[JimD]

Thanks for all the replies. I still do not know exactly what happened and maybe this is self serving but I think the Joey just failed rather catastrophically on its own. I intended to return it to Dish by now but haven't yet, we'll see what they say. When I learned that the circuits were separate, I started to lean heavily that direction. Your 220V theories were interesting and seemed plausible until I thought of the fact that all three circuits come off the same 120V leg of the breaker box.

I thought some might be interested in the resolution. We aren't done yet but this incident refuses to go away easily. We bought a new TV last week on-line from Best Buy. It was a couple inches bigger than the one in the room it will be located and 8 inches larger than the one that failed. It was supposed to be delivered to the store yesterday. Yesterday I get an email saying that it will be Wednesday. I was pretty pissed because I was off yesterday and had time to install it. So we went shopping and bought one a couple inches larger that they had in stock. Nobody had the 48 inch we ordered. So I get it home, put it on a new wall mount, and it works great off the hopper feed. Then we try to stream Netflix and Amazon. It never worked right but we did get Netflix to work once. So I started a chat on-line with Vizio (it's an e series) and my stupid computer decided to end the chat on me just as we were getting somewhere. So we went to dinner and I called them when we got home. After a bunch more diagnostic, they wanted to send somebody to the house in 10 days with a new one. Instead I will take it back to Best Buy today. So repack, drive to store, unpack and hope the next one works. Seems like nothing is easy on this. If the next one works, I guess I will consider Vizio in the future, it does look nice and has nice reviews. But right now I wish we had gotten a Roku TV like I wanted (Vizio was LOML's choice). I also got a Roku 3 for the other TV (an older non-smart TV) and of course it fired up very quickly and streams everything we've tried great. I could put a Roku on the Vizio but I hate to just keep a defective product. Seems like for what even an entry level TV costs these days it should work. Hopefully one more try and we're done (I will also move the wall mount for the second time today, LOML changed her mind on height). Some projects just don't go smoothly.

The second one works fine. It still switches to streaming a bit funny but it works for both Amazon and Netflix so it is a keeper. Sometimes the dedicated keys will work without going to the dish box first and sometimes they won't. Sometimes you can go from Netflix to Amazon without TV first but most of the time not. If I am patient and use the Vizio key then the dedicated key it seems to consistently work.

The more important reason to edit this is to suggest a Joey substitute - a way to have a second TV off the one DVR box (i.e. the Hopper). The hopper is accessable via "Dish Anywhere" on a laptop, phone, or tablet. Most laptops and some tablets have HDMI out. So we ordered an inexpensive 10 inch tablet from Walmart and a HDMI cable (couldn't figure out it's port size so adapters for each are coming) and we will use the dedicated laptop and HDMI cable through the Dish anywhere app to watch TV on that TV. The additional hardware payoff is between 6 and 7 months. And I doubt the tablet will ruin the TV. With dish anywhere you can access either the tuners (i.e. live TV) or the DVR. You can also transfer the DVR output to the tablet to watch without a network connection (like on a plane). So while it's a little klugy it has advantages too.

Jim