HP PL4260N Arc/POP/Crack (bad Plasma tube?)

[billansor]

Hi

This HP PL4260N came in with the complaint of a loud bang/Pop/Cracking sound and the set went dead.

Opened it up and found that the power supply two large input filters were bulging. Checked to find that they both read close to 330UF and no leakage (they were out of circuit when tested) Re-installed the filters as I did not have any replacements)

A fuse was blown in the high voltage section of the plasma power (Picture number two in the upper right side). The fuse (4 amp) was replaced and the set powered up. When the set was on for about 5 seconds... There was a loud exploding type crack (arc) and the fuse blew. It was like a filter cap blew but no evidence of a blown cap... No smell like a blown transistor or resistor..

Can the Plasma tube go bad and arc?

Could the bulging filters which checked good... be bad to where it would have caused the high voltage to the plasma to exceed it's capacity and arc to discharge?? Would replacing them make any difference?? or a waste of money??

Bill (Thank you for your answers and help)

[rayrod81]

Re: HP PL4260N Arc/POP/Crack (bad Plasma tube?)

Pictures will help but it sounds like you have a shorted component on the supply. A blown fuse pretty much confirms it. The problem you have now is that you replaced the fuse and may have further damaged the power supply when you powered it on. It is usually not a good idea to replace a fuse and turn a TV on again without finding the fault that caused the fuse to blow. When you do this it sends a surge through components that are normally protected by the fuse and usually causes more problems on the board.

[billansor]

Re: HP PL4260N Arc/POP/Crack (bad Plasma tube?)

The 2nd picture is the one where the fuses are... On this board, the diodes, filters, and other semiconductors were checked for shorts..

My main question was in respects to a fault in the plasma tube and if it would create the loud cracking /arc sound..

Bkill

[PlainBill]

Re: HP PL4260N Arc/POP/Crack (bad Plasma tube?)

The 2nd picture is the one where the fuses are... On this board, the diodes, filters, and other semiconductors were checked for shorts..

My main question was in respects to a fault in the plasma tube and if it would create the loud cracking /arc sound..

Bkill

Maybe, I've never seen a shorted plasma panel.

However, this illustrates the importance of taking pictures first, asking questions, and then following advice; or alternatively doing a little research before replacing fuses and seeing if it works.

You have the infamous LG Electronics 42X3xxx plasma panel. The card you are referring to is NOT the 'plasma power', it is the Y-Sustain. And they are notorious for shorting 'with a bang'. Hidden under the black heatsink on that card is a hybrid, which has shorted.

PlainBill