Inverter board - red LED

[dumpystig]

There is a red LED mounted on the master inverter board and I want to know its purpose.
When I power the TV the inverter kicks in and the red LED illuminates and the screen backlights power on. Then, after about 3-4 seconds the red LED dims and goes off completely. Is this operating correctly or should the LED remain lit whilst the TV is on? The TV runs fine, although after having problems with the PSU (which I fixed) I'm wondering if there may be any other slight faults that may be looming.

TV: Sanyo CES37WSD7-B
Inverter: LG 6632L-0197D (Master)

Thanks for any help you may have.

[dumpystig]

Re: Inverter board - red LED

Ideas anyone? Tons of googling and I can't find any info whatsoever...

[Dgtech]

Re: Inverter board - red LED

This may or may not be the symptoms that are common with the inverter board plague that philips had. There is no way I can comment further without seeing pictures of the boards in question. Use "Manage Attachments" on the post page when adding photos.

[dumpystig]

Re: Inverter board - red LED

Hi pal, I'm afraid I can't post any pics of the inverter board atm; the TV is fully assembled and my 4 year old son is watching Turbo Man as I write... no way am I telling him it's getting switched off! But I will return with a pic in the next day or two. As I said, the TV is now working fine, it's just that I'm curious as to the function/operation of the LED.

[dumpystig]

Re: Inverter board - red LED

Just found this pic, borrowed from the net. Any help to you?

[Dgtech]

Re: Inverter board - red LED

Well, it seems as if it hasn't broke enough for it to be fixed. It will in time. I would check the caps on the inverter board and the power board for this type of failure.

[dumpystig]

Re: Inverter board - red LED

Yeah, it's running fine. But all I want to know is simply whether the red LED on the master inverter board should remain lit when the TV is running or if it should extinguish a few seconds after being powered on... The PSU and Mainboard are functioning as they should, all V's are as stated in the literature I have obtained.

[Longbolt]

Re: Inverter board - red LED

I'm just inventing something for you so you can feel safe;
Here or somewhere else I red that on some televisions, and because the tubes have a lifespan manufacturers can put clocks or time counters so servicers can know if they should change the lamps.
As in a ofice lighting fluorescent tube they start to dimm and flicker because there is not enough current flow trough them due of aging of heaters filament.
So when your tube starts in the beginning gases are colder and is slightly under loaded so led can light, as it heats more current is drawn and da led dimes.
Probably with time approaching to the end of life of the tube or one of them will pass less current then normal and led will stay on all the time so the man who will open the tv will see that is time to change a tube or tubes. This can be cheaper alternative of those digital time counter. Once again is just an idea.
I recently discovered that in the night my eyes turns rubis-red but never got warred even thaw is terribly disturbing.

[jsog]

Re: Inverter board - red LED

The LG tcon from this thread has a blue LED that lights on powerup and fades out a few seconds later. It must be some sort of diagnostic because it's covered by a metal shield. That particular TV is only partly working, but I suspect the LED behavior is a normal "I'm alive" indicator.

[dumpystig]

Re: Inverter board - red LED

OK thanks for your input. I guess I may never know the relevance of the LED, but it would have been good to satisfy my curiosity.