lenovo t430 no backlight

[aligatiganga]

Re: lenovo t430 no backlight

Hi,
I have the similar problem but there is voltage on fuse F7.
I am not sure what else needs to be checked.
external output to any display works fine.
any help is much appreciated.

Thanks,

[dj_ricoh]

Re: lenovo t430 no backlight

Hi,
I have the similar problem but there is voltage on fuse F7.
I am not sure what else needs to be checked.
external output to any display works fine.
any help is much appreciated.

Thanks,

you need to try a broken screen just to see if its the screen or cable.
find a cracked screen connect it and see if you got backlight.
if not you need to check all the wires from the cable .
continuity check.
after you need to check the voltage on the lcd connector.

[aligatiganga]

Re: lenovo t430 no backlight

you need to try a broken screen just to see if its the screen or cable.
find a cracked screen connect it and see if you got backlight.
if not you need to check all the wires from the cable .
continuity check.
after you need to check the voltage on the lcd connector.

there is no backlight.
continuity check was good. but there is not voltage from the motherboard lcd connector pins.

but when i connect to TV using docket station or through HDMI or VGA it works fine. problem is now only with zero voltage at all pins in LCD 40 pin connector on the motherboard.
i appreciate if i can get any schematics to find the faulty element.

Thanks.

[Hannahparked]

Re: lenovo t430 no backlight

What do you mean you soldered the little wire over the original fuse? Can you go into more detail on how you fixed this issue? thank you

I just did this today, here's a better photo of the wire and where you should check the connections. I will say the fuse is tiny and you need to solder it very carefully. I bought a 3A fast blow glass fuse and used the wire. I held the wire (with a tweezer) to one end of the fuse and lightly touched the wire/fuse with a bit of solder already on the tip of the soldering iron, then bent the wire over the other side, cut the excess off, then soldered the same on the other side. Good luck!

[Hannahparked]

Re: lenovo t430 no backlight

I just did this today, here's a better photo of the wire and where you should check the connections. I will say the fuse is tiny and you need to solder it very carefully. I bought a 3A fast blow glass fuse and used the wire. I held the wire (with a tweezer) to one end of the fuse and lightly touched the wire/fuse with a bit of solder already on the tip of the soldering iron, then bent the wire over the other side, cut the excess off, then soldered the same on the other side. Good luck!

Hmm, picture isn't inserting, here'a link:

https://drive.google.com/file/d/0B61...it?usp=sharing

[ktmmotocross]

Re: lenovo t430 no backlight

it looks like a real CRAP work. u dont have any spare SMD fuse from any scraped elektonic?

[dj_ricoh]

Re: lenovo t430 no backlight

that's a big wire!
I cut a adapter cable not with cooper and I use those wires so so tiny.

[soda]

Re: lenovo t430 no backlight

Hi,
I have similar issue. Blown fuse while replacing the lcd screen. I did a big mistake and measuring the lvds signals when battery was inserted (the laptop was off at that moment). I can confirm that fuse F7 is protecting the LVDS backlight psu. I can "fix" that by soldering *VERY CAREFULLY* wire over the blown fuse - note that you can use pads of surrounding capacitors to solder the wire. Also note that you need higher temperature and solid micro soldering iron, as this is Pb-free components.
Regards.

[Andy at the oaks]

Re: lenovo t430 no backlight

Hi all
I'm new to all of this but followed the advice on repairing F7 fuse on the board with conductive paint and a fine needle as a paint brush. BUT, it didn't work, still got a dark screen. So, I turned the board over and looked around the connector for the lcd cable, which is on the reverse side from F7 . Sure enough, I found fuse F3 had also blown, so I've now attempted repair of that one too. Fingers crossed that it works.
Mental note, next time my screen goes a bit crazy, take the battery out before you start digging around. ......

[redm0nk]

Re: lenovo t430 no backlight

Hello Guys,
I have a Thinkpad T430s laptop and I am trying to replace the lcd screen. I think I have blown up a fuse or something because I saw a little smoke/spark which came out at the connection. I did a big mistake by replacing lcd while battery was connected (the laptop was off at that moment).
Now, I have the backlight problem where very faint visuals can be seen on the LCD. So, my question is how should I go about fixing this issue?

Any help is appreciated.
PS: the external display monitor works just fine, it is just the display on the laptop which is very dim.

[yaaqbeh]

Re: lenovo t430 no backlight

SOLVED!
the fuses from first pictures are for battery.
the fuse for the screen its marked with F7 and its under the connector
i do know that it req. 20v

thaaaaaaaanx it works

[jhook32073]

Re: lenovo t430 no backlight

Hi, I am also a VICTIM of the F7 Blown Fuse however I did the solder as it was posted and it worked GREAT for a couple of months. Last week i was using in the laptop surfing the web and all of the sudden the screen blanked out. I thought may be it was the OS had reset itself. Then when I went to turn on the laptop all you can see is a very dim dark screen. I took the laptop a part and check the solder. The connection was good. I checked the other fuses on the board and they checked OK with my mulit-meter. Can any else think what this can be? I am in a stand still. I also tried switching the video cable and manage to get another screen to test and it does the same thing. I am at a point maybe I should just replace the board. Any help would be appreciated. Thanks

[dj_ricoh]

Re: lenovo t430 no backlight

How much voltage you got on both sides of the fuse?

[mijiman]

Re: lenovo t430 no backlight

SOLVED!
the fuses from first pictures are for battery.
the fuse for the screen its marked with F7 and its under the connector
i do know that it req. 20v

tho this is an old post, i would like to thank you dj_ricoh very much. your work saved my budget and probably my job. had same problem with F7 fuse. I only put a 2A fuse...hope it lasts. TY again

[HotIronVal]

Re: lenovo t430 no backlight

Another old thread revival here, just thanking dj_ricoh. Those photos really made it easy to find the component and for me to fix this laptop.
FWIW, I did the solder bridge because I'm not at all convinced that it's actually any worse than using the wire from the inside of a glass fuse, and seeing as the board is $50 on eBay, I couldn't justify paying Mouser almost $10 (shipped) for a pinhead sized fuse that I wouldn't even be certain would work.

Using a needle, I painted the top of the fuse with flux. Then I heated my iron with a 1mm tip so it would melt solder instantly when it touched. Then I put a small dab of solder on the tip, and touched it to the old component for a split second. Before bridging reading of several mega ohms. Now reading is .03 ohms. I am happy, and so is the friend I did it for.

[DagonSoul]

Re: lenovo t430 no backlight

Bloody hell I got lucky with this... I just put a bit of solder across and it worked. No magnify glass or anything!!! And at 42 my hands are no good at steady work anymore!

So anyway, yes this fix works! Thank you all.

[forsberg]

Re: lenovo t430 no backlight

thanks for this topic !
I repaired today a backlight in two T4xx with this metod

I was mega upset on myself, b'cos I've forgot to remove a battery during lcd- swap ...

so I start to check voltage, resistance etc. on the famous F7 fuse ... and it was like above dj ricoh said.

total cost of repair - 5 $ ( my time and nerves not included)

for the rest of my life I will remember how to install a Lcd in laptop

thanks!

here is a photo just in case :
https://drive.google.com/file/d/0B2v...ew?usp=sharing

[zare]

Re: lenovo t430 no backlight

W541 here with same problem. How hard is to get to the back of the motherboard where the fuse is?

[zare]

W541 LCD back light fuse

Just to update: used this Lenovo service instantiations to disassemble. The offending fuse for me was F14. Its was beside the LCD connector, but it is kind tight to solder without dissembling. Got some glass fuse wire(3A) and solder on top of the fuse.

[vxedcc]

Re: lenovo t430 no backlight

Thank you all

Same problem as described in this thread. stripped laptop to find the F7 had died in spectacular fashion.

will take to specialist to get repaired in the morning.