bypassing a backlight lcd bulb

[rivette65]

i have 10 Nec lc19m lcd monitors
the problem is that the screen goes dim after 30s .and i found that in every one there is a bad backlight bulb : that's why it goes dim i
i have tried to put an external bulb instead of the bad and the monitor does not go dim . and i have realise that with only one bulb the brightness of the monitor is good . so instead of changing a second new bulb i want to use only one . but the problem is the feedback circuit : with only one bulb the screen shuts down .
ihave you any idea about what to connect in the bulb connector on the inverter to bypass the detection of the bulb or to bypass the feedback circuit
thank you

[alexanna]

Re: bypassing a backlight lcd bulb

Use the advanced search feature and type in [ backlight with a resistor]
You will get some ideas.
Al.

[rivette65]

Re: bypassing a backlight lcd bulb

thank you Alexana . i will try to look for this solution
. have a nice day

[Krankshaft]

Re: bypassing a backlight lcd bulb

Rearrange ohms law if you know the bulbs voltage and current you can calculate the resistance.

[rivette65]

Re: bypassing a backlight lcd bulb

hi
i'm sure that there is a better solution ! i mean a modification at the primary ( before the high voltage) to disable the cut out . i have a tl494c on the board . have you any idea ?

[PlainBill]

Re: bypassing a backlight lcd bulb

hi
i'm sure that there is a better solution ! i mean a modification at the primary ( before the high voltage) to disable the cut out . i have a tl494c on the board . have you any idea ?

Yes. I grew up on a farm. Farming equipment has shields to restrict access to rotating shafts, cutting blades, crushing bars, etc. Also you would find placards warning the user to turn off power before removing the shields. Many farmers ignored the warning. They were often known by nicknames such as 'Lefty', 'Three Finger', 'Thumbs', 'Peg Leg', 'Stumpy', etc.

Safety features are installed for a reason. Disabling them is a stupid idea!

PlainBill

[lucky13]

Re: bypassing a backlight lcd bulb

Once I left a good tube inside the monitor to bypass the bad lamp. So now there is light at the back of the monitor illuminating the wall a bit. It works OK.

[PlainBill]

Re: bypassing a backlight lcd bulb

Once I left a good tube inside the monitor to bypass the bad lamp. So now there is light at the back of the monitor illuminating the wall a bit. It works OK.

Ambilight!!

[rivette65]

Re: bypassing a backlight lcd bulb

thank you for your help
i have replaced all the backlights ! it was the best but not easy solution.

[lucky13]

Re: bypassing a backlight lcd bulb

Congrats rivette65! Good for you.

[rivette65]

Re: bypassing a backlight lcd bulb

thanks Lucky13