T21 Motherboard Replacement - Soliciting Help!

[ryoustra]

Greetings All -

I'll spare you the long, long narrative of my T21 probs, but thanks to this board and elsewhere I've concluded that I have the dreaded overcharged capacitor problem.

Symptoms had deteriorated to only having the fan spin up and the hard drive and the power indicators come on when I tried to start the machine. No boot, no Thinkpad splash screen.

I ordered a replacement (refurbished) motherboard over the weekend and installed it. Symptoms now are a bit worse, that I got only a quick flicker of the hard drive indicator and nothing else.

Suspecting that my replacement motherboard was defective, I popped my old one back in and got similar results: fan no longer starts, and only a quick flicker of the hard drive indicator. Nothing else.

So: both the new motherboard and the old motherboard leave me in a somewhat worsened state. I took pains to reinstall everything carefully and tightly, and even replaced the CMOS battery, thinking that that might be part of the problem. No luck!

Any thoughts on what might be wrong such that powering on the laptop gives only a quick blink of the hard drive indicator and nothing else, particularly given the swap in motherboards and cmos batteries?

Many thanks,
Ray

[Orevin]

Remove the hard drive, optical drive, modem/NIC, memory, USB devices... and try to boot. If it works, add the removed components one by one, starting with a memory chip.

[ryoustra]

Thanks... I'll try it, specifically as you described, although I *think* I effectively did that over the weekend without much luck.

Incidentally, does anyone know what minimum components are required to at least get the "IBM Thinkpad" splash screen? i.e., should I be able to get some response with just the motherboard, CPU/fan, attach the screen and pop the keyboard back on to be able to hit the power button and see *something* ???

[skygodtj]

Pul out everything but one memory chip.. You should be able to get into the BIOS with the bays open(no drives), but enough memory to post.

TJ

[ryoustra]

Removed almost everything but the CPU/fan... took out the hard drive, pcmcia cards, optical, battery, NIC card, etc. Popped the keyboard back on to hit the power button and still only get an instantaneous flash of the battery indicator and the hard drive indicator. Nothing further.

I'm getting this symptom with both a newer refurbished motherboard as well as with my older one that I'm attempting to replace.

Any helpful thoughts would be greatly appreciated!

[tfflivemb2]

Pulsating fan? Possibly...... before I finally succumbed to ordering a replacement motherboard, one of the symptoms - in addition to not booting - was that the fan seemed irregular to be sure. Almost like it was running at half power, then maybe back up higher for a second or two, then back down. Not necessarily a fast pulsating sound, but it was definitely unusual.

[Note: I did mention in the other thread that I pulled out most of the components except the cpu/fan and a stick of memory, and still only get a quick flash of the battery light and the hard drive indicator]

Thanks much for jumping in with your thoughts on this.

If you feel like removing the systemboard again, pull it out and flip it over. Check the little round PCBs and see if they are completely connected to the systemboard. Here are two pics of what I am talking about, even though they are on a T23:

Pic #1

Pic #2

[ryoustra]

Thanks... I pulled it out again (I'm getting quite good at that now, actually) and saw nothing loose if that's what you mean. The T21 board is different enough from the T23, so I'm not exactly sure what to look for, but everything seems secure.

[Orevin]

It looks like both of you need a new system board.
ryoustra, you might try another CPU, but I'm quite certain, that the "refurbished" board is broken as well. Where did you get it? Any warranty on it?

[ryoustra]

60-day warranty... got it from MetInt.com. Had never heard of them before, and website seems a little off, but they responded to a request for a quote and seemed fairly responsive. Caveat emptor, eh? But it was one of the only places I could find a motherboard for the SXGA+ T21.

[Orevin]

I have a spare 700MHz CPU, if you want to give it a try.

[ryoustra]

Thanks so much... I'll ping you on that separately. Two general q's though:

(1) my T21 is the 850MHz, so will the 700MHz work in it?
(2) if the CPU was the problem, would it have the symptoms I'm seeing: quick flash of the Hard Drive and Battery indicators, and nothing else?

[Orevin]

Thanks so much... I'll ping you on that separately. Two general q's though:

(1) my T21 is the 850MHz, so will the 700MHz work in it?
(2) if the CPU was the problem, would it have the symptoms I'm seeing: quick flash of the Hard Drive and Battery indicators, and nothing else?

1. Yes
2. I'm only pointing at the CPU, because you swapped the system board already. I don't know the symptoms of a dead processor. As I said before, the "new" system board is probably broken as weel, but it won't hurt to check the CPU.

[ryoustra]

WOOHOO!!! IT'S FIXED!!!!!

Thanks to everyone for their helpful suggestions, particularly to Orevin for his offer of letting me test with his CPU. What a terrific community to have stumbled into...

As it turned out, the one thing I didn't understand when I took my laptop apart was how to remove the CPU. I unscrewed, thinking that would remove the whole base that the CPU was set into. The screw got "stuck" and so I disregarded it as soon as I realized the CPU was loose already, assuming that I didn't need to remove the base after all. What I didn't realize was that the screw was a locking mechanism for the CPU. Thus, when I put everything back together, I never locked the CPU back in place, thinking the fan assembly was what held it secure. Obviously that's why it never even came close to thinking about booting.

QUICK Q: with all the repeated assembly/disassembly, the Arctic Silver between the CPU and the fan was pretty smudged. Is this a source for concern, or should it be OK?

Thanks again, folks.