Blown T420 backlight fuse, potential risks if jumping/briding?

[rocketjordon]

Hello,
I recently bought a T420 that had a broken screen (or so I thought). A broken screen was OK for me since I anyhow was about to do some upgrades, including a 1600x900 panel, but also flashing coreboot onto to it and installing an ivy bridge processor.

So I got all the needed parts, flashed coreboot successfully, put everything together (with the new panel)... and still no picture... Now, I was able to verify that the laptop is working (except for the screen) by using an external monitor + Fn&F7 + live Linux image. Also, while in the live session, if I open some bright sharp pictures I am able to see them on the laptop screen if I point the brightest flashlight I got at the screen. So from what I have read on forums this points to a blown backlight fuse.

I opened up the laptop and found the fuse (verified with multimeter that it is blown), but it is tiny and I am not skilled enough to do the replacement, nor can I source the replacement fuse locally (and having it delivered to where I live would be half the price of a replacement motherboard from ebay). So I am thinking of just jumping it.

But before I do, I would like to know the risks of jumping it. If whatever caused the fuse to blow occurs again, what components can I damage? Basically I am OK with killing the motherboard, since that is useless to me anyhow if I get no picture, but the rest (cpu, ram etc...) I would not like to damage. Also, I got a new LCD cable because the old looked splintered/ripped at the screen connector. Maybe that caused the fuse to blow and therefore it should not happen again now that I got a new cable... maybe? Your thoughts?

[RealBlackStuff]

Welcome to the Forum.
The most likely blown fuse is either F19 (0.5A, marked F), or F3 (3A, marked P).
Both are described as "fast-acting".
Do NOT bridge a blown fuse, you run the risk of blowing something else!
If you can manage to solder a wire to each end of the fuse on the board, you can then solder a new fuse (of a larger size if you like) between the other ends of the fuse.
Alternative: piggyback-solder the new fuse on top of the old one.

[jronald]

On some earlier machines I have soldered a single strand of a 14 gauge stranded wire over the two ends of the fuse. Then a bit of tape to insulate the [censored] fuse assembly.

(It does not like the word Bas tard ized?)

Ron

[TPFanatic]

When I blew the backlight fuse (F7) on my T420 I just bridged it with a wire and it seems fine, for now. :\ Can't sell it like this, though.