Minimum T21 rebuild to test for Blink of Death BOD (or not)?

[dj123]

Greetings from Australia from a novice Thinkpad repairer. I've gained a lot of useful info from browsing this forum, so I thought I'd join and ask 2 questions. I did not find the answer by looking in the forum posts.

I have a T21 which was fine and then developed BOD (as in AC power on, one HD blink, nothing). Partly as a learning experience, I've pulled it apart into carefully labelled bits. I've also bought a cheap dead T21 at auction - not here yet so not sure of its state but hopefully will have a working mobo. If that fails, I might be able to get a working (so the seller says) T22 mobo on eBay. Then by parts swap I might be able to identify the problems in both and get both working.

Anyway, the questions:
1. what is the minimum rebuild I need to do to test whether BOD present or not?
2. will any CPU from a T2x mobo work in every other T2x mobo (though possibly slower, due to slower model CPU)?

My thinking so far:
The LCD ribbon and two white connectors at the rear of the mobo are easy enough to connect. I imagine the CPU can run for a couple of minutes without the fan fitted. And it seems I can press the speaker module onto its contacts to listen for 1-3-3-1 no RAM, which presumably means no BOD. But the Power ON switch is associated with the keypad, which I separated much earlier in the disassembly.

Any help on this appreciated.
BTW, I know this is not good use of time and $. I just can't resist the challenge.

[rkawakami]

Welcome to thinkpads.com and G'day!

Taking your last question first, you can power up the T21 without any keyboard by mounting it to a port replicator which has its own power button.

You could certainly try running a T2x system without a fan but you should get a BIOS error. If you do get that far, then you don't (at that moment anyway) have a BoD issue. Same goes for the speaker assembly. You don't really need one as long as you have one known good memory module installed. If the power LED remains lit after you push the power button, then again, the board is not showing any BoD problem.

From my standpoint, since I have some T23 motherboards to go through, the best bet would be to source a spare base where you could mount the motherboard, the fan and speaker if need be. Connected to the aforementioned port replicator and external monitor, you should be in a good position to repeatedly power up the system. Can't say for sure how many times you need to successfully power up the board before you can declare it free from the Blink of Death.

As far as the CPU swaps go, I'm not sure. I have swapped 1.13Ghz and 1.2Ghz CPUs in the T23 motherboard without any problems but I don't know the limitations of the T22 and earlier systems. Probably your best bet would be to consult the Hardware Maintenance Manual to see what was normally paired up with each other.

http://www-307.ibm.com/pc/support/site. ... UYM3F.html

[dj123]

Thanks for the prompt reply.

Further to my question about minimum rebuild: As it would take time to get a docking station, just now I secured the mobo to the base with 1 rear screw; connected LCD ribbon and 2 white connectors at rear of mobo (near ribbon); pressed kbd onto black mobo kbd socket; connected power lead to rear input; pressed ON key. Result: all green lights blinked. I quickly removed power. Presumably this means BOD not present (as of now - I know it can be intermittent).

However, though early days, this seems promising. My plan now is to leave the T21 in pieces until my auction T21 arrives and I assess its state and maybe do some parts swaps to help diagnose it.

I'll rebuild the first T21 in steps and try powering it up at each step, to see if I can add any useful info to the BOD saga.

If I can rebuild my current one to fully working condition, presumably it means "my" BOD is not due to component failure. I have not replaced anything, resoldered etc.

I'll post the eventual result here.

[RealBlackStuff]

Between T20/T21/T22 you can swap CPUs, but the fastest one is a 1.0GHz.

These are CPUs with the Intel Numbers SL53S and SL5TF.
To be able to use those, you need to do a BIOS and Embedded Controller update to the latest available versions. (Do this with the old CPU still in!)
You will also need to use the cooler/fan assembly of a T22.
And just in case, do apply AS5 (Arctic Silver 5) instead of a thermal pad.

-- You can NOT use any CPUs from a T23 --

[tfflivemb2]

RBS and Ray have it right, but to subtract one less step...you don't need to attach the LCD ribbon cable. You can leave the base/port replicator attached to an external monitor.

[dj123]

Here are the recent ups and downs of my BOD problem, which is extremely inconsistent and frustrating. I'd appreciate any thoughts on what I might do next. I can see this ending with me selling the BOD T21 for parts. But I'd still have my other, recently revived and working T21.

Following the manual, I stripped the BOD T21 down to the remove mobo stage. I examined the extracted mobo - no obvious solder, connector, mechanical problems.
I started rebuilding the T21 module by module. I tested each stage by powering up the rebuild, which you can do if you hold the keyboard in place on its mobo connector.
At each stage the full set of green LEDs flashed. I thought - at least not BOD. LCD display still black, but maybe that is as it should be at this point.
After I attached the speaker, I heard 1-3-3-1 beeps. Promising, I thought.
After inserting 1 RAM stick, I got two beeps and blank LCD. In the manual, this means POST failure - mobo or RAM problem. I know the RAM is ok from testing it in my working T21 and I tried it in both slots of the BOD T21.
After reading forum posts, I thought - add external monitor to T21 (I do not have a docking station).
Monitor showed F1/F12 BIOS screen and complaint about no hard disk. Even better, I thought.
I added the hard disk from the other T21 and the BOD T21 booted up Win2000. LCD blank. I thought, I can nail this, probably a LCD connector problem.
But on next power up, with nothing changed, BOD has returned!

Maybe this BOD is an intermittent mobo problem. I'll strip the T21 down again and try reseating the CPU, which I did not do before.

However, any ideas on the above which I should look into during the rebuild? Thanks.

[matthewpoer]

Frustrating, isn't it? The Blink of Death does seem very inconsistant. But, please think about this: how was your system using power during the re-build?
Was it AC or battery? Did you make sure to disconnect when adding/removing modules (please say yes!), and how long was it plugged in each time?

My theory is that once the machine with BoD has been plugged (could be on or off, but is reciving charge from AC or Battery) in for X amount of time, it will not boot without waiting Y amount of time.

I suspect that the ratio of X:Y is roughly 1:4. So, if you used your machine for about half an hour and then turned it off and removed power sources, you can expect to use it again in two hours or so. This ratio probably varies depending on X, and should reflect the way that a capacitor will naturally lose power over time.

[dj123]

Strip/rebuild process: Remove battery for whole process. AC adapter removed completely when any work under way. To test, AC connected for a few seconds, result noted (eg green LEDs light), AC removed.

Funny you mention that elapsed time issue. You might be onto something there:

After BOD on Sun night, I turned the T21 on Mon night (on battery power), mostly out of curiosity. It booted to BIOS on external monitor connected to T21. No LCD display.

After I powered off and inserted HD, it booted Win2000.

Same for AC power only.

So this BOD is so erratic, it will be hard to ever be sure it is fully fixed.

BTW, I have been told that a BIOS update might help the problem. As it seems I can sometimes get Win2000 to run, anyone think I should do a BIOS update on such an occasion?

Regardless of BOD, I will pull the BOD T21 apart again, as I want to swap some undamaged plastics into the good T21.

Thanks for any further thoughts on this tedious saga. BOD will be on my gravestone.

PS: BOD T21 booted Win2000 this morning (Tue). No ext monitor connected, and I could see a faint but identifiable Win2000 logo in the LCD. It's not a burntin image. Does this imply anything about the LCD, eg faulty component, loose connector?

[dj123]

Further on my T21 problem in above posts.

A couple of local people suggested to me that a BIOS update might fix BOD. So I flashed the BIOS from original ver 1.07 (KZET26WW, 2001-05-15), Embedded Controller 1.01 to latest BIOS ver 1.16 (KZET34WW, 2004-04-28), Emb Cont 1.06.

And it seems to have fixed BOD (so far). Previously the T21 would only boot up occasionally after 1-2 days rest with no battery or AC connected. For the last few days post BIOS update, it boots Win2000 ok every time (as viewed on ext monitor), regardless of past time on or off, powered off with or w/o battery and AC.

So I'd advise any BOD case which does not have latest BIOS to try the update as one easy option.

Now to pull the T21 apart again to see if I can fix the faint ghost Win2000 image in black screen problem.

[nikki605]

I think you are going to be disappointed. In August, 2004, I upgraded my T21 to WinXP and at the same time (08/11/2004) updated my BIOS to ver 1.16 (KZET34WW), Emb Cont 1.06.

My T21 continued to work fine after the WinXP & BIOS update until December, 2006, when I experienced my first BoD. For more details, see my post in this topic: http://forum.thinkpads.com/viewtopic.php?t=61102

Sorry to burst your bubble.

[SMA]

The reason for trying a bios update as a cure for BoD, should be to get the flash memory erased and re-written,
because it is expected that the flash memory may sometimes not read correctly.

It is not expected to be a programming error that is causing the BoD to occur, so the program version does not matter.

And yes, it is possible to re-flash to a version similar to the version already installed.
It is also possible to flash to an older version.

The phenomenon of flash memories loosing their content is not new - it has been seen elsewhere.

And there are many other places in life where similar things happen.
Take an old floppy disk that has not been touched for years. It may not read its old content correctly, but still it can be formatted and
new data can be written and read back from it successfully.
The disk it selves is as good as new, but the old data on it has been lost.

[dj123]

Thanks nikki605 for that info. I live in hope that BOD has gone, but any BOD-free time is better than none. At least I can run diagnostics to help analyse things. And my experience suggests to me that my BOD is not the usually speculated power chips, capacitors, dry joints etc. Otherwise why would bootup reliability have improved so much, when the only change is BIOS update?

[dj123]

Further to the story in above posts re my ghost image LCD.

Thanks to Msmax and Robbyrobot for their previous posts on pins 56 and 9 of the LCD cable (esp Robbyrobot for the pics). I tried that test with a multimeter which showed open circuit (should show zero resistance). So, given the symptoms (faint Win image in LCD), looks like a new or repaired LCD cable is needed.

The IBM manual says the FRU is 27L0519. It seems this will be hard to obtain in Australia, and even then might be expensive. However I could get a 27L0640 which seems to be for T22/23 14.1" LCD. But I have seen posts on eBay and elsewhere suggesting it might work in a T21 (mine is 2647-8AA, 14.1" XGA LCD).

Any experts here know if 27L0640 will work in a T21 type 2647-8AA? Thanks again for any help.

[dj123]

To complete the story in the above posts:

I swapped parts between my two incomplete/faulty T21s and now have one perfect T21 and one residual faulty T21 which I will try selling on eBay.

I updated the BIOS on the faulty one and the BOD went away for a while. However as speculated above, it returned. But intermittently. So the faulty one boots up often enough for me to take demo pics of the working LCD. What causes my BOD is still a mystery to me. I did not detect any pattern in its occurrence and my attempted fixes, except perhaps that the BIOS update gave a distinct but temporary BOD alievation.

For the LCD backlight problem, I tried the robbierobot idea of soldering a wire between pins 9 and 56, despite not having fine enough solder tip, solder or wire. I filed a point onto an old solder tip. It worked and the LCD now displays well. However I have to say it is not an easy job to carry out in absence of the right equipment. My result is far from professional and may not last long term.

All this has been a useful learning experience re laptops. Thanks to those who took time to post replies to my questions, and to all those posters in the past whose stories I found very useful and informative.