One of my latest T23s from eBay showed a familiar symptom: It would power up but not display anything either on the LCD or external video. The only signs of activity were the power/battery LEDs and a steady processor fan. Thinking I had a motherboard issue, I started to strip it all of the way down to the system board. However, along the way I noticed that the screw/cam in the processor socket was slightly askew. Thinking I had an easy fix, I tightened the screw, put the laptop into a port replicator and hit the power button on it (I did not bother to re-install the keyboard). Voila! The screen lit up, the IBM splash screen appeared, a configuration error (CMOS battery was missing) and then the BIOS screen. Okay... power off, remove from port replicator, re-assemble the entire system and turn it back on... to the same problem! AARRGGHHH! Strip it a second time, this time all the way to removing the motherboard. Poked around.. didn't see anything obviously wrong. Decided to once again mount the system into the port replicator and power up. Once again, it worked! What's going on?? Does the system only power up when using the port replicator power button? Put the keyboard back on (with everything else removed except the CPU) and pushed the button.. it still worked. I decided to re-assemble the system one piece at a time and check to see if the laptop was still able to power up. I finally got all fhe way back to where the ethernet and combo wireless/modem card were to be put back when the bells in my head went off. DUH! One of the first things to do when faced with a power up problem is to remove all removable hardware and see if it works. If it does, then replace one component at a time and re-check for proper power-up. In my case, the wireless/modem combo card was the culprit. Removing that one part allowed the system to boot normally.

Yeah, those cards can cause all kinds of problems when they die.

Glad to hear that you have it up and running!!

Bringing back a "thread from the dead"...

Another eBay parts/repair special... same symptoms... powers up, all of the proper LEDs lit like they should be, constant, full speed processor fan, no beeps, but no internal or external video, boot or BIOS access. System stripped of everything (HDD, Ultrabay, modem/wireless, ethernet, PCMCIA, CMOS and main batteries) and still the same results: does not display any video activity, no boot access on the floppy drive, no beeps (even w/no memory), nada. To simplify my troubleshooting I normally put the system into a port replicator for power, external video and floppy drive. These are the things I have checked:

-The LCD screen (SXGA+ w/antennas ) works on another T23.
-A known good LCD appears dead with this system.
-All of the fuses that I can find on the motherboard are okay (although I may have missed some).
-Memory is good in other T23 system
-Using the power button on the keyboard or on the port replicator gives the same results.
-Even tried disconnecting the I/O board so that the only things I had connected to the motherboard was the CPU, memory, keyboard and LCD.

I'll leave my rant about the slight misrepresentation of the auction description for another thread and instead ask these questions:

-Can I swap the existing 1.13Ghz processor with a lower-speed version without causing any damage/problems to either the motherboard or the known good processor? I've checked the T23 HMM and it appears that any processor can be used in any motherboard, but I've never dabbled in CPU swaps so I figured I'd ask some experts. This appears to be the last component that I can isolate as a source of the problem. If that doesn't work, then it's time for another motherboard.
-Most of my power checkouts are without the heatsink/fan assembly installed. I'm assuming that this will only cause an error code to be generated and not something that will prevent a startup. Correct? The system has only been powered up for a minute or two without the fan and the CPU does not even get warm. The Savage graphics chip and the Intel 82801 I/O controller do get noticeably warmer, but not too bad.

Any comments or suggestions will be appreciated. Thanks!

You can swap out the processor and test it, and it shouldn't damage it, unless there was some freakish problem with the system board. Besides, the 1.13 and 1.2 CPUs aren't too expensive, if you need another one.

Actually, it sounds like it might be the processor. It has been my experience thus far that 99% of the time it is the system board in laptops, versus the CPU....but this case sounds like it might be a little different.

You could certainly test the CPU in another system, and test a different CPU in this system.

Well, the CPU in the new system was not the issue.

Not wanting to disturb a totally working system, I took one of my "problem" T23 systems apart to get at the 1.13Ghz CPU and heatsink/fan assembly. Said system has (had) a problem getting past the IBM boot splash screen. It would sit there forever regardless of how the machine was populated. I removed the 1.2Ghz CPU out of the newly arrived system and put the 1.13Ghz one in and closed the cam on the socket. I figured if there was something wrong with that processor, the hanging symptom would transfer to the new system. I plugged in the fan and it immediately started turning ( !). WHAT? In my haste to perform the swap, I neglected to remove the laptop base from my port replicator. The system was powered up when I removed and replaced the processor . Thinking that now BOTH processors were toast, I powered the system off and then re-started it. Still the same symptoms... constant fan, no video anywhere, etc. Well, if the 1.13Ghz processor never had any problems it probably does now!

Okay, take the 1.2Ghz processor from the "dead" system and throw it (gently) into a confirmed un-powered system. Re-install the keyboard and press the power button. Expecting the worst, I was surprised to find that the system booted normally, giving me a "fan error" and "time and date error". Hey, maybe I didn't fry a processor after all. Power down, re-install the fan, correct the date/time in BIOS, boot into a copy of PC Doctor on CD and begin running some diagnostics. Everything seems to be fine. All of the system board and CPU tests pass.

So my problem with the new system seems to be confirmed that it's on the motherboard. I've also found out that I have a bad 1.13Ghz processor which causes the boot screen freeze. Not a bad morning...

Try reseating the "bad" 1.13 back into its original system and see if it works again. It might have needed reseating.

The newer T23 definately has a toasted mobo.

Spoke too soon .

The older motherboard is now definitely toast. It even had what looked like an orange LED light up on the motherboard for a few seconds, in a place where no LED existed before. Actually, it is, strike that, was a transistor of some kind (Q16). In conjunction with that cool orange glow, some (well, probably all) of the "magic smoke" that is placed inside each electronic component to allow it to do its job escaped. Which also goes to prove the rule that semiconductors protected by fuses will blow first, thus protecting the fuse. Bummer.

The bright side of all of this is that I now have some incentive to start swapping around some pieces among my "projects" (mainly LCD panels). The confusing part is that I thought I had a 1.13Ghz processor in the older system. Looking closely at the CPUs, they are both 26P8005, making them 1.2Ghz. During all of this swapping around I now am not sure which processor is which. Since I didn't have anything to lose, I plugged each processor into the new system and it still acts the same. At least the processor wasn't the cause for the LET (that's Light Emitting Transistor in case you haven't figured that out...).

I need some chocolate.

<--- Light Emitting Transistor (200K picture link)

At least that's what I think I created today, based upon the "Q16" marking next to it on the motherboard. With an average life of 3 seconds, I think I need more development work before I apply for a patent .