Testing and possibly replacing x41 Tablet power jack

[por986]

Hello,

New to the forum and came across it while researching fixes for my beloved x41 Tablet.

The quick history... power supply failed (made a ticking noise and meter showed it to be dead) and instead of attempting to repair it, I bought a cheap $20 knock off which reported to have the needed voltage/ampreage - bad mistake. The knock off worked for about 9 months but killed both of my batteries. So, I was living with the plug always attached, until the laptop failed to start one night.

Using a multimeter, I determined that the knock off had died as well. I now have an OEM power supply that I have verified is working, but the tablet does not respond in anyway; no lights, fans, noises, nada!

Question 1:
Hoping I don't have a bad motherboard, I want to check the DC jack. My question is, do I need to remove the MB to get to the leads? With the keyboard and top 'framing' removed, I don't see anyway to test it as the connections appear to be on the bottom of the MB.

Question 2:
Is there a fuse associated with the jack that I can test/verify?

Thanks in advance.

[por986]

So I think I was able to test the jack without removing the MB. There is a GND labeled near that jack and using a solder joint just near the jack, I was able to get proper voltage on the board. Not sure how accurate my test was, but it appears that it is getting power.

What else could I test on the board to make sure it is receiving power properly? Is there a way to test voltage on the keyboar, drive, memory, etc?

[rkawakami]

Welcome to thinkpads.com!

Lacking the proper circuit schematics (IBM has never publicly released these documents), it would be very hard to tell you what pins to check for voltages. The usual diagnostic in such a case is to remove all of the hardware from the system that's socketed (except the CPU). Take out the hard drive, all memory, MiniPCI card, CDC card(s) (modem, ethernet, bluetooth, PCMCIA, USB, etc.) and then try powering up the system. If it comes alive, you should get the 1-3-3-1 (bad or missing memory) error code, except in cases where there's memory soldered directly onto the motherboard. If it does power up, then start replacing components one-at-a-time until the system again refuses to power/boot. The last item installed is/was the problem.

If the system does not power up/boot when everything has been removed, then that usually indicates a motherboard problem. With lots of patience and circuit tracing it may be possible to discover what's gone wrong with it. You could try looking for all of the fuses on the board and checking them with an ohmmeter. I'd say that there's 6-10 fuses on the typical IBM Thinkpad motherboard. Most of them will be labeled with an "F" number nearby (i.e., F2 or F8). There's also a possibility that one (or more) components have bad solder joints. If you really are dedicated, you can determine where the power (VDD) pins are located on a DDR2 module and see if the proper voltage is getting there. Don't know if the pinout for the 1.8" drives is the same as for the "normal" 2.5" IDE drives.

However, the normal advice would be to simply replace the motherboard with a known working unit.

ref: http://download.micron.com/pdf/technote ... TN4703.pdf (DDR2 SODIMM pinout)

[por986]

Thank you for your reply.

After poking around aimlessly, I found some areas on the MB that returned readings (e.g. microphone pins at 0.5V). Still not sure what can be causing it as there were no symptoms prior to it just dying :-\ I have rarely seen a MB failure without some symptoms over time such as BSODs, random lockups, etc. Strange.

The only pluggable item that I haven't removed is the wireless card. Will do.

I have seen various laptops behave differently, so does the battery need to be attached and functional for the laptop to come online? Secondly, do you have a recommendation for a motherboard purchase? If the price is reasonable, buying one might be the way to go - my time is worth more than troubleshooting for days on end.

Final question, any suggestion on pulling my data off of the HDD? It is apparent that the Hitachi is a one off design, and I am not sure where I can get a USB enclosure or adapter (USB would be ideal).

Thanks again!

[rkawakami]

MiniPCI cards (wireless and combo) in T2x systems, when they die, can make the system look like it has a power-up issue. Not sure if the X41 suffers from the same condition. If the change was sudden, and pulling the wireless card does not help, then double-check the fuses. You will need an ohmmeter/multimeter, set to the lowest OHMS range (if it has manual range settings). I thought I posted an image of the fuses that are in a T23 but I can't seem to find it right now. I would imagine that IBM used the same type of surface mounted fuses in their systems. Anyway, put the meter leads across the ends of the fuse; they usually have metal endcaps. If you read 0 ohms, then the fuse is good. If it measures more than say 5 ohms, I'd consider it dead. That gets you as far as knowing that it's bad, the trick then is to identify the current (amperage) rating and find someone that sells just ONE, without taking you to the cleaners with the shipping and handling costs. I've order these types of fuses from both Mouser.com and Digikey.com and they have offered single-unit quantities.