Re: LCD CFT backlight inverters

From: James Sweet (jamessweet_at_hotmail.com)
Date: 11/22/04 

Date: Mon, 22 Nov 2004 23:46:36 GMT

"BOB URZ" <"sound(remove)"@inetnebr.com> wrote in message
news:41A263CD.63605FBC@inetnebr.com...
> I got in a 17" LCD monitor with a dead backlite. It had a sampo
> QPWBGLQ231DLF inverter for dual CFT lamps in it. It had no voltage on
> either bulb, so i pulled the inverter board out.
> It had a TI TL1451 controller chip in it. I downloaded the TI spec ***
> and found the pin out. Then found no B+ voltage on the chip.
> Looking closely, i saw would appears to be a small surface mount
> fuse that was open on the B+ line. It did not have a numeric value
> stamped on it. For testing, i jumped the SMF with a small strand
> of wire from a multiple core wire. After i did this, it brought the
> displays backlite back to life. Anyone revived one of these inverters
> before? Nothing seemed to be shorted on it and it seems to work ok
> now. Any ideas on the SMF fuse value or type? What would cause the fuse
> to blow on an otherwise working unit?
>
> Bob
>

Possibly just a defective fuse, it happens sometimes, mechanical damage can
break the link just as it can burn out incandescent lamps. As for the fuse
value, measure the current draw and select a fuse rated for about 50% over
that.

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