Thinkpads Forum

I have a 750CS that refuses to boot up. When I plug it in and press the power switch, I get the LED's flashing, then after about 5seconds I get 2 beeps, then the screen goes blank and the 2nd/3rd/9th LEDs (batt, something, and sleep-mode?) come on and stay on.

on the screen when attempting to boot, I do see what appears to be a black bar about 3 inches long down the far left column. I cant see the entire text but I see (x)904 KB OK so I am assuming the ram is ok?

I do believe the CPU/BIOS are ok because after the laptop had been sitting on a shelf for many months I plugged it in and I did get the options for setting time and date. Althoigh, I dont know how or if I can get it to boot direct to BIOS for verification (DEL, of F8? I tried both)

I have two different hard drives, and had tried with both, and with none, same results. I have also tried with the battery removed, same result. and, I have tried to boot with the keyboard raised and me holding down the key-switch, just above the battery. again, same result. The laptop wont boot from battery, it never did when the laptop was working.

I know this laptop isnt really worth putting any money into it but I would love to get it working again if possible.

Patrick

oops, my mistake. when booting up I get ONE beep then it appears to go into standby/hibernation mode. then if I press the power button after that I get 2 beeps. if I unplug the power, wait a few seconds, then plug it bavk in and press the power button it goes thru the above again, with ONE beep. and pressing the RESET doesnt seem to make a difference either.

Woohoo! Another 750 owner!

Be VERY careful!

While this ThinkPad (and many others) are powering up, they write to the security chip (the one that holds passwords and checksums) to test it. If power fails during this process, you can get a bad checksum, and the chip has to be replaced. It is usually cheaper to replace the motherboard since you can buy this machine for about $5 on eBay.

Test your CMOS battery and replace it if needed. That's the flat one. The standby battery isn't so critical.

You need a Y-adapter to connect an external keyboard to this machine.

Get into the BIOS (EZSetup) by holding F1 while you turn the machine on.

There is a tiny switch on the right side of the case that closes when the lid is closed. That may have a short so it's telling the machine that the lid is closed... but that should be OK. Try using an external monitor and power up with the lid closed.

Get out of suspend by pressing the blue Fn button.

I have a 750P that I recently resurrected. IBM recently put the BIOS back on their site, so update that once you get it going.

where is the CMOS located? I dont see it when I lift the keyboard.

Patrick

Read this site's FAQ to find out where to get your Hardware Maintenance Manual. The one for the 750 series is called Volume 2. It has instructions for finding and replacing everything, and tests for a few things.

In the mean time, the CMOS battey is under the floppy drive.