No signs of life

[brucehe]

Hello all,

I have a t23 that does nothing on battery or ac adapter when the start button is pressed.

It is a community laptop that was working fine however I think the battery is dead. I changed the battery with a t21 that is OK and that does not help either.

Is there a fuse that could be bad or could it be the on / off switch? I do have a t21 I can trade parts with and do some testing.

Guidance on where to start would be appreciated.

Thanks,

Bruce

[rkawakami]

Could be a number of things given the symptoms. Here's a list of things, in descending order of possibility:

- Defective MiniPCI card; pull it out and try powering the system up
- Keyboard connector loose from motherboard; press down on the "Y" key as the connector is right underneath it
- General power problem on the motherboard; would have to swap it out with another one to verify
- Broken power switch or defective keyboard; swap it with a known good one
- Blown fuses; there's one protecting the DC input jack (F2) and another for the battery (F12)
F2: http://www.kawakami-ca.com/ibm_t2x/let.jpg (top edge of photo)
F12: http://www.kawakami-ca.com/ibm_t2x/main_fuses.jpg (large blue outline)

[brucehe]

I pulled the mini PCI card no luck.

Keyboard is seated although I have not changed it out with another yet.

Another piece of information. When I pushed the on / off button I can hear a low level noise, almost a hum, maybe like the fan is stuck? I pulled the keyboard and the fan spins fine. I thought it might be the hardrive but pulled it and the noise is still there. I do have a t21 bottom with a bad system board so I could swap the fan if it is the same one.

Any idea what could be making noise?

thanks,

Bruce

[rkawakami]

The fan/heatsink assembly is different between the T23 and earlier T2x systems. Don't know what could be causing the hum other than a transformer/inductor or something coming from the speakers.

[brucehe]

The fan assembly I had was the exact same FRU so I tried it but no luck.

All the fuses on the boards look OK.

I am going to pull the keyboard from a working t21 and see what happens.

The noise seems to be coming from a large inductor? labeled 6R8 (it has some blue paint around it)

Bruce

[rkawakami]

That would probably be the inductor at location D5 in this photo: http://www.rkawakami.net/ibm_t2x/mobo_top_72_legend.jpg . If so I think it's tied to one of the main power supply controllers on the motherboard (MAX1631). I don't know what could be causing it to hum. Maybe the CPU is shot or there's a short somewhere on the board.

There's about a dozen fuses on the T23 motherboard. The F2-type fuse can be visually inspected but to be sure, use an ohmmeter to check for 0 ohms (all power removed from the system).

If you haven't already tried, pull out all removable hardware from the system and see if that allows it to power up. Hard drive, memory, ethernet, modem, wireless, Ultrabay, etc.

ref: http://forum.thinkpads.com/viewtopic.php?t=37956

[brucehe]

OK, I pulled all the components and still no go. I assume it must be a system board problem. Is it worth troubleshooting at the board level?

Thanks,

Bruce

[Majestic]

If you have the time, removing the motherboard and checking it over is a fairly easy operation. The on-line manual pretty well details the disassembly and past forum discussions here documents the component locations. If your problem is related to the inductors, more than likely one or both sides on the contacts are visibly loose.

[brucehe]

Thanks all for the troubleshooting advise, new board installed and we are back in business. Now that the pressure is off I might try to repair the board. How do you work with surface mount devices and a soldering iron?

Bruce

[rkawakami]

Removing parts with two terminals like inductors, fuses and chip caps can be done fairly easily with a standard, low-wattage (~25W) soldering iron. What's really needed are good eyes and steady hands. However, if you are talking about removing/replacing ICs with 8 or more legs, then that's a whole 'nother story. For those types of parts you need an SMT re-work station.

For the aforementioned two-legged components, you can usually heat up one side of the part and then when the solder melts, switch over to the other side, get that junction to melt and then push away the part using the soldering iron. You don't really need to remove a blown fuse; simply solder the replacement right on top of the old one (i.e., piggyback). For inductors, once removed you should remove all of the old solder and then lightly scrape the bottom metal pads until they are bright copper. They tend to develop "black pads" or oxidation and that, along with motherboard flexing and/or multiple heat-cool cycles, will cause them to separate from the motherboard.

[brucehe]

Unfortunately the saga continues. I have been working on the machine, getting drivers updated, defragging the disk and running cc cleaner and patting myself on the back about how good it was running. I shut down the machine and came back a few hours later to run it and it will only power on the fan and sit there. I pulled everything, all cards and same response. Is the "new" system board dead or?

Not sure what to do next. Any assistance is appreciated.

Bruce

[Majestic]

Very possible that you have an inductor problem with that board as well. If were me, I would check over your first motherboard since you already have it out on the work bench. You might be able to find the problem and re-install it after fixing.

[brucehe]

The board I installed was new so not sure what is up with that. I can't imagine a bad inductor joint but I will inspect.

I did remove the other system board and it does have a broken solder joint on an inductor on the bottom side. I think I will try to repair but it is very close to an IC. I might see if I can find someone with a soldering iron with a smaller tip.

Do I need to remove the component as Ray suggested or can I try to just flow the broken pad joint with a bit more solder?

Bruce

[Majestic]

"The board I installed was new so not sure what is up with that. I can't imagine a bad inductor joint but I will inspect."

Even brought as new, you have to consider the board is still xx years old. Jarring during shipment or flexing of the board during installation may have been all it needed to weaken a connection. A couple of thermal cycles after that and you have a bad joint.

"I might see if I can find someone with a soldering iron with a smaller tip."

It is not that difficult of a job if you have basic soldering skills. Your local Radio Shack will have a 25 watt soldering iron for around $9. Otherwise any electronic repair shop should be able to fix it.

"Do I need to remove the component as Ray suggested or can I try to just flow the broken pad joint with a bit more solder?"

It is best to remove the inductor completely, clean up the area, flux and then resolder both contacts as Ray suggested. Reason being, if one solder joint is bad chances are the other isn't far behind in failing. The link below is for another thread about inductors with tips on how to repair......

http://forum.thinkpads.com/viewtopic.php?f=28&t=21979

[brucehe]

OK, I tried soldering on two different inductors that were broken loose. I put it back together on my extra bottom case which has with no cards or memory installed. I got a beep code and the fan running which was very exciting since this board did thing nothing before. I proceeded to put the rest of the pieces together including adding the lcd. I started it up it did what the other unit did, fan started and that was it (the only common part to the other unit is the LCD). I removed the lcd and pulled all the cards and memory one by one to see if I could get it to beep again. Nope same symptoms, fan running and that was it. I then tried replacing the keyboard with one I knew was good, no change.

I just read the piece on repairing inductors. I think I will pull the system board again and do some better inspection and check continuity of the inductors. There is some common problem I am missing. Any other suggestions appreciated. I am close to having to reinstall quickbooks and the data to another machine.

Bruce

[Majestic]

At this point my only suggestion would be to recheck the board. Possibly during the reconstruction the board got flexed a little and another connection let loose.

[brucehe]

The person I purchased the system board from was going to send me a new one so I removed the board. Something did not make sense so I took it out, inspected it and found no open solder joints. I then decided to put it together again together checking for system beeps before I installed memory, cards ,etc. Well it worked, so I just kept adding pieces and checking for beeps. It worked until I put in the memory. I then removed one stick and it worked, moved it to the other slot and it worked and then put the other stick in and it still worked. I put the hardrive in and it booted. I guess the memory was not seated quite correctly. I am using the machine now so we will see if it keeps going.

I now have some time to play with the other board. I also have a dead one, from someone plugging a 30V DC power supply into the t23. I can use it to practice my soldering.

Thanks for all the assistance and support.

Bruce

[brucehe]

The final episode I hope.. I received a replacement system board from a great Ebay person and installed it in about 20 minutes ( I can do this very quickly after about 5 tear downs). It worked on the first button push. I guess there was an intermittent on the new board he sold me that I could not find. Lesson, 100% feedback after a few thousand transactions on Ebay gives you a better chance of great customer service. Also, a new part can be bad. I got a lot more confidence tearing down these machines and might take on a T400 if needed.

Bruce

[Majestic]

Glad to hear the system is now up and running. Thanks for posting back with an update.