T20, only fan and LEDs work, replacing m-board didnt help

[soxiquail]

So I’ve got this IBM T20 that I like to write papers on (and take to Starcraft lans!). I used to let my girlfriend take it to work at her boring desk job. She brought it back one day saying it was broken and she didn’t do anything to it. So I don’t have a clear idea of the initial symptoms.

At first it used to load partway, then beep angrily and stop. I couldn’t get it to access the BIOS or anything because the keyboard appeared to have failed. But after awhile it stopped going even that much. So, currently:

Symptoms:
-Attaching the main battery or plugging in the power will cause the system to activate immediately and apparently start a boot process. There is no POST beep, and the screen remains completely black (not just backlighting problem). The fans run, and the power indicator light comes on, and the hard drive light does one small flash and then remains off (I have heard that this is indicative of Hard Drive failure?). Pressing the power button does nothing, and the order of plugging in battery or power source affects nothing, and I have tried it with both and with only one or the other.

What I’ve tried:
-Removing battery, banging it around, trying again.
-Leaving battery alone for several months and then trying again.
-Holding down the power button with battery and main power detached in order to drain capacitors.
-Pressing power button dozens of times quickly when both on and off.
-Plugging in the power sources in various orders with the laptop both open and folded up.
-Pressing down the standby button (you know, the one that is triggered when the screen is folded down)
-Removing extra components (like the LAN card and CD drive)
-Tried everything with and without the BIOS battery.
-Pressing all of the other buttons (idle mode, monitor switch, etc)
-Pressing every combination of buttons I can think of (alt+esc, ctrl+alt+del, F8, etc)
-Plugged it into a working monitor (nothing came on screen)
-Finally, I replaced the motherboard and tried all of the same things, with all of the same results (i.e., no success, and also NO changes in ANY results).

So, uhh.. any more suggestions? Maybe the physical power switch is broken? Maybe the motherboard went bonkers and fried all of the components? I saw no popped capacitors on anything, no burns, etc.

Thanks,
Tom

[rkawakami]

Welcome to thinkpads.com! Wish it could be under better circumstances .

Well, usually when you replace whatever logically seems to be the source of the problem and it still doesn't fix things, then you look at whatever hardware or software that is common between the two states.

In this case, are you using the same keyboard? A stuck power button may be the source of your problem (as you surmise). To verify this, try the following:

- remove the keyboard from the laptop
- apply power via the AC adapter

Does the system remain off (like it should)?

If yes, replace the keyboard.
If no, then is there some other hardware that is common between the two, like maybe the CPU?

[soxiquail]

Okay, I tried plugging it in without the keyboard. It doesn't start or do anything. Which is good! However, I did notice that the area of the CPU emits a very faint high pitched buzzing. I seem to remember hearing this in the past, when the machine was working, as a normal sound that the power system makes. Plugging in both battery and AC results in the same sound, but the battery by itself does not.

So should I just replace the keyboard at this point? Is there another sort of test that I can run before investing money into a new KB?

[rkawakami]

The only other thing I can think of to futher implicate the keyboard as the root cause of your problem is to attach the laptop to a port replicator or docking station and use the power button on that device to power up the system. If you do have access to one, and the system powers up normally, then I think you've found the problem.

T2x keyboards are available off of eBay for about $15. I've purchased some from the seller "xreplay" and others here have also used that seller (use the search button at the top of the page and plug in xreplay in the "keyword" box). Most of his auctions have been setup as Buy-it-Now, with a "Make an offer" option. If you cannot or do not want to use eBay, then put up a notice here in the Marketplace forum.

As far as the buzzing is concerned, the system I'm using right now does have a faint, high-pitched whine when the system is on. Doesn't matter if it is being powered by AC only, battery only or both. It does NOT make any noises when the system is off (and with the AC adapter still plugged in). I have assumed it's due to loose windings on the inductor right next to the CPU. I don't know if there's one there in the T20 system or not.

[soxiquail]

alritey, I've ordered one. thanks for your help, i'll let everyone know how it goes

[Highwayman]

Don't rule out the I/O board that sits at the very back of the laptop. This board is separate from the MB. The switch that detects a closed condition with the lid could mimick the same symptoms if it
has gone bad. The laptop will stay in hyberate mode. Power-on will show the bios, but after that everything goes blank. Just a suggestion.

[soxiquail]

Well, it sort of worked.

I replaced the keyboard, and now the unit DOES turn on and off (isn't stuck ON all the time anymore).

But the screen is still black all the time (no power getting to it, not just a blank screen) and the unit doesnt seem to be doing much activity.

So I think that the only reasonable conclusion is: the CPU.

I checked Ebay and theres T20 processors ranging from $7 to $130. What's the catch?

[soxiquail]

Oh, and I also tried plugging it into a monitor. No dice.

[tfflivemb2]

Now that the system seems to power on, try connecting it to an external monitor and see if you can "Fn" + "F7" several times to switch between the displays, once the power is on.