This guide will attempt to help you diagnose some common problems with plasma TVs. It applies to most manufacturers of plasma TVs.
Some background about plasma TVs (feel free to skip)
Most plasma TVs are made by three major manufacturers. Samsung, LG, and Panasonic are the most common. There are some older manufacturers, including NEC, Hitachi, Pioneer, etc. which are no longer in the business of manufacturing of PDPs.
A PDP is essentially a module sold to a manufacturer. The PDP comes with the glass panel which contains a mix of noble gases. It is vital that this panel is not damaged as a crack may lead to the gases escaping, making the panel a very expensive and very heavy paperweight. (It is NOT possible to re-gas a PDP module, at present at least.) The PDP also comes fitted with the Y-buffers, Y-sustain, Z-sustain, control board and X drivers. In some cases, it may come with a power supply.
The PDP is manufactured by one of the larger manufacturers. If, for example, you buy a store-brand plasma TV, the retailer has made a contract with a company somewhere in the Far East (probably...) to make a Plasma TV for them. This manufacturer will buy the PDP module from the PDP manufacturer (LG & Samsung usually sell modules - Panasonic doesn't usually) and put some other components with it such as the main board and a power supply, and put it in a case, then ship it off to the retailer.
If you buy a plasma TV from one of the bigger manufacturers that make their own PDPs, then the manufacturer has supplied their own boards and put their name on it.
Boards in a plasma TV
A plasma TV contains at least:
From now on I will be using LG terminology as it is more familiar to me.
Tools of the trade
I highly recommend you have at least:
If you have an oscilloscope with a rated minimum of 400V inputs and a 10X probe that is also very useful.
DANGER: A plasma TV has voltages in excess of 380V on some connectors. The capacitance on the Vsus bus (>4,500uF) is easily enough to jump-start your heart and can power the TV for half a second with a fully white picture, that's over 200 joules. UNDER NO CIRCUMSTANCES TOUCH ANY PART ON THE BACK OF THE TV WHILE IT IS RUNNING OR SHORTLY AFTER POWER OFF! I highly recommend you have someone around you watching you while you service your TV in case you do make a mistake.
Identifying the fault
The first step is to identify the fault in question. Does the TV power up? Is there a picture? If there is a picture, is it clear? Are there any signs of "sparklies" or image retention on the screen?
Were you using the TV when the fault occurred? Was it gradual, or did it suddenly happen? If the TV doesn't give a picture any more, does something smell like burning plastic? Was any smoke emitted from the back of the unit?
[Continued below.]
Some background about plasma TVs (feel free to skip)
Most plasma TVs are made by three major manufacturers. Samsung, LG, and Panasonic are the most common. There are some older manufacturers, including NEC, Hitachi, Pioneer, etc. which are no longer in the business of manufacturing of PDPs.
A PDP is essentially a module sold to a manufacturer. The PDP comes with the glass panel which contains a mix of noble gases. It is vital that this panel is not damaged as a crack may lead to the gases escaping, making the panel a very expensive and very heavy paperweight. (It is NOT possible to re-gas a PDP module, at present at least.) The PDP also comes fitted with the Y-buffers, Y-sustain, Z-sustain, control board and X drivers. In some cases, it may come with a power supply.
The PDP is manufactured by one of the larger manufacturers. If, for example, you buy a store-brand plasma TV, the retailer has made a contract with a company somewhere in the Far East (probably...) to make a Plasma TV for them. This manufacturer will buy the PDP module from the PDP manufacturer (LG & Samsung usually sell modules - Panasonic doesn't usually) and put some other components with it such as the main board and a power supply, and put it in a case, then ship it off to the retailer.
If you buy a plasma TV from one of the bigger manufacturers that make their own PDPs, then the manufacturer has supplied their own boards and put their name on it.
Boards in a plasma TV
A plasma TV contains at least:
- Y-buffer (sometimes in two parts, a Y upper and Y lower). This connects to the Y-sustain.
- Y-sustain (Samsung call it an Y-main and Panasonic call it an SC board). This is almost always on the left of the screen when you look at it from behind.
- Z-sustain (Samsung call it an X-main and Panasonic call it an SS board). This is almost always on the right from behind.
- Control board (sometimes called T-con and not to be confused with LCD T-con boards). Often buried under a main board.
- X driver - sometimes fitted to the control board or integrated on it.
- Power supply
- Main board / AV board / Tuner board - the board with the input connectors, antenna etc. on it
From now on I will be using LG terminology as it is more familiar to me.
Tools of the trade
I highly recommend you have at least:
- A digital multimeter. An analogue multimeter will not suffice.
- A Phillips-head screwdriver
- Patience
If you have an oscilloscope with a rated minimum of 400V inputs and a 10X probe that is also very useful.
DANGER: A plasma TV has voltages in excess of 380V on some connectors. The capacitance on the Vsus bus (>4,500uF) is easily enough to jump-start your heart and can power the TV for half a second with a fully white picture, that's over 200 joules. UNDER NO CIRCUMSTANCES TOUCH ANY PART ON THE BACK OF THE TV WHILE IT IS RUNNING OR SHORTLY AFTER POWER OFF! I highly recommend you have someone around you watching you while you service your TV in case you do make a mistake.
Identifying the fault
The first step is to identify the fault in question. Does the TV power up? Is there a picture? If there is a picture, is it clear? Are there any signs of "sparklies" or image retention on the screen?
Were you using the TV when the fault occurred? Was it gradual, or did it suddenly happen? If the TV doesn't give a picture any more, does something smell like burning plastic? Was any smoke emitted from the back of the unit?
[Continued below.]
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