T42 does not boot

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screwdriver · #1 Post by **screwdriver** » Thu Apr 24, 2008 4:00 pm

hello,
my first post and already a problem...
I have a T42 mainboard with radeon 9600 and started to run it with minimal hardware.
battery charges if ac is plugged in, but I can't turn it on.
when I press the power buton battery light flashes for a second and the screen shows reaction but nothing displays. no fan, no hard drive no optical drive, nothing moves. then the light turns off and additional usage of the button won't work until I plug off the cable.

can anybody help?

ps: pressing on gpu or chipset doesn't help...

Robbyrobot · #2 Post by **Robbyrobot** » Fri Apr 25, 2008 7:54 am

Do you have at least one RAM stick (Pc2100 or PC2700) installed?

If so, and you have such problems, I still would assume a GPU defect. The only other thing you could try would be to check all the fuses you can find with a multimeter, and make sure all the inductors are properly soldered. If those are also OK, then "flexing" is probably the problem. I don't know of anyone reliable and inexpensive in Germany who treats this kind of problem, but you might talk to (write) jamiphar in this forum, as he's apparently set up to reball BGA chips.

P.S. Schöne Grüße, Schraubenzieher

screwdriver · #3 Post by **screwdriver** » Fri Apr 25, 2008 10:46 am

I have tried with and without ram.
I need to get a multimeter, then I can check the fuses.
how do I know, if inductors are soldered properly? there is one "thing" directly left beside the gpu (1R7MM492) that looks not correctly installed (it is asloped). what is this? could that be the reason?

ps: zurück nachbar!

screwdriver · #4 Post by **screwdriver** » Fri Apr 25, 2008 11:02 am

it is exactly this part! with slight pressure on it the boatd runs!!!
how can I fix it? I've never soldered a mainboard...

#5 Post by **rkawakami** » Fri Apr 25, 2008 11:55 am

Does it look like this: http://www.kawakami-ca.com/images/inductor.jpg

This is the bottom side which mounts to the motherboard. The two copper pads at the top and bottom of the photo is what is supposed to be soldered onto the board. If it is this part, then you should scrape off any grey or black "film" on those pads before you attempt to re-solder it. What seems to work for me is to apply a tiny amount of solder on each pad before you place it down on the matching pads on the motherboard. Use a small-wattage soldering iron (~25W) with the finest tip you can get for it. Heat the side where the metal pad wraps around and apply a small amount of pressure down on top of the part. That should attach one side. Then heat the second pad on the opposite side.

screwdriver · #6 Post by **screwdriver** » Fri Apr 25, 2008 12:44 pm

it's still attached on one side, but the shape is exactly the same!
your description is a perfect help for me, I'll try to fix it soon.
should I first take off the inductor conmpletely or leave the one good soldering and just try to fix the second?

ps: do I need special equipment? I have an ordinary, cheap soldering iron for 230V AC, the tip is sharp and on the top less then a mm wide.

#7 Post by **rkawakami** » Fri Apr 25, 2008 12:54 pm

I would remove the inductor and clean off the pads since if one side lifted up, the other side may eventually loosen as well. But that's your call. It would be simpler to just re-solder the one side if you can manage to get some new solder underneath the inductor's pad.

No other equipment should be needed other than the solder iron, some solder and a pair of good eyes.

screwdriver · #8 Post by **screwdriver** » Fri Apr 25, 2008 1:09 pm

thank you very much, I'll post my result the next days!

#9 Post by **richk** » Fri Apr 25, 2008 1:19 pm

You need to apply flux first. Make sure it is "no-clean" rosin flux. I just solder the one side that is off, pressing down in the middle to insure a good contact. Then I put flux on the other side and remelt the solder there to make sure there are no little cracks.

screwdriver · #10 Post by **screwdriver** » Fri Apr 25, 2008 2:15 pm

i soldered it and until now everything works perfect (testing with knoppix live cd).

thanks to all who tried to help!
this forum is great

screwdriver · #11 Post by **screwdriver** » Sun May 04, 2008 7:32 am

hello again,
running pretty stable for a week now the thinkpad won't turn on any more.
first it did not start when a battery was plugged in, now it won't boot at all.
this morning I was running it and now nothing happens.
the soldering I made is still fine...

do you have any ideas?

screwdriver · #12 Post by **screwdriver** » Tue May 06, 2008 1:12 pm

does anybody know where to get a new inductor from?

T42 does not boot

T42 does not boot

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