T40 Won't Power Up

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Wasted · #1 Post by **Wasted** » Thu May 03, 2007 8:53 pm

I have been attempting to upgrade my T40 (2373-12U) to an SXGA+ screen. At first I didn't know I needed the SXGA+ screen cable so I had disassembled the T40, swapped the panels and wound up having to swap the old XGA back until I got the correct LCD cable.

Today the cable arrived, and I disassembled the T40 again. As soon as I could I connected the SXGA+ panel and inverter to the motherboard and tried to power my T40 up (to check that the LCD works correctly). However, it wouldn't boot.

Now regardless of what panel is connected the T40 will not boot. It powers up for about a second then shuts down. I tried removing all unnecessary components (optical drive, HDD, extra memory, WiFi and Bluetooth card). But the problem remains. I also tried reseating the CPU but that didn't have any effect either.

I hope I haven't broken my motherboard, that would be a real PITA as I bought the T40 to replace my Acer which had a dead motherboard.

Does anyone have any suggestions on how to revive it?

#2 Post by **richk** » Fri May 04, 2007 4:42 pm

When you first took it apart to remove the LCD, did you remove the fan? IS the fan connected? Did you use thermal grease? Immediate shutdown sounds like overheating, but 1 second seems soon. Is the memory seated correctly?

dc_slim · #3 Post by **dc_slim** » Fri May 04, 2007 9:29 pm

Have you tried disconnecting all power supplies? This may seem obvious, but I had a T40 that would behave exactly the same way sometimes. Before I could get it to boot normally, I'd have to remove the battery and unplugging the power supply, then reconnect them. Then it'd work fine.

Wasted · #4 Post by **Wasted** » Sat May 05, 2007 12:28 am

richk wrote:When you first took it apart to remove the LCD, did you remove the fan? IS the fan connected? Did you use thermal grease? Immediate shutdown sounds like overheating, but 1 second seems soon. Is the memory seated correctly?

Even with the fan disconnected, it would take more than a second to reach a thermal shutdown temperature. Keep in mind that the fan is off most of the time anways. And yes, the memory was reseated a few times. And I tried replacing both the CPU and memory with spares.

dc_slim wrote:Have you tried disconnecting all power supplies? This may seem obvious, but I had a T40 that would behave exactly the same way sometimes. Before I could get it to boot normally, I'd have to remove the battery and unplugging the power supply, then reconnect them. Then it'd work fine.

Yes, I've tried that too. What happens is that pressing the power button will start the laptop. The status LED's on the back of the LCD inverter turn on and flash for a bit and the CPU fan will spin up. After a second or so, the fan and LED's will turn off and stay off. At this point, pressing the power button again has no effect, and the only way I can try starting it up again is to remove the battery and AC.

bontistic · #5 Post by **bontistic** » Sat May 05, 2007 12:42 am

Could be because of a possible temp increase or a short circuit somewhere. Check to see if there are no cables or connectors in contact with parts that are not supposed to be in contact with.

#6 Post by **richk** » Sat May 05, 2007 10:29 am

If you don't have a wireless card, make sure the cable ends are not touching the pci slot contacts. I have seen similar problems if the cable is creating a short there.

Wasted · #7 Post by **Wasted** » Sat May 05, 2007 2:42 pm

Well, when I disassembled the T40, I removed the antenna cables entirely from the base, so they wouldn't have been touching when I had it disassembled. I have reassembled it so keep all the parts together until I figure out what to do next.

Do you guys think it might be a good idea to pull the motherboard entirely and try to power it up outside of the case (on an anti-static bag, of course) to eliminate the possibility of a short? I suppose if the motherboard is toast it will at least give me some practice at replacing a motherboard.

bontistic · #8 Post by **bontistic** » Sat May 05, 2007 3:04 pm

I'd say it is much safer inside the base than outside on top of other materials. Besides, protective circuitry will prevent the motherboard from being fried to a certain extent.

You can check the DC-in area since while removing and re-connecting the LCD cable, there is a slight chance that you have stripped off some insulation on these wires?

#9 Post by **richk** » Sat May 05, 2007 6:18 pm

I agree. Don't try to test it outside the case. It is too easy to "cook" something. Did you remove the CPU? Is it possible you didn't turn the screw to reconnect it? Also, make sure the memory is in straight. If the memory module isn't correctly seated, it can cause your symptoms. I am looking for easy things where nothing is broken. I am an expert on stupid mistakes, because I have had a lot of practice making them.

Wasted · #10 Post by **Wasted** » Wed May 09, 2007 11:48 am

Well, I've just purchased a replacement motherboard off eBay, the specific board is for a T42 (/w an ATi 9600). And I'll be swapping it in once it arrives.

I have a copy of the user dissasembly guide thingy for the T4x off lenovo's website, but are there any caveats I should watch out for that might not be described there? Or better yet, does anyone have any guides on how to do the swap?

Furthermore, I don't think it will be an issue, but the motherboard I purchased has the hard drive air-bag system, and the fingerprint scanner, of which my T40 had neither. But I've heard that all T4x boards are interchangeable. Can anyone confirm?

T40 Won't Power Up

T40 Won't Power Up

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