Neato! I know this isn't the place to pu t this but I just noticed right now that I actually have a title under my name.

I just want to say thank you to those that have helped others in this thread, as you have now helped me! I acquired another T23 recently that worked fine until the other day-it started the pulsing fan problem. I pretty much knew what it was from reading this forums, so I got the chance this afternoon to completely dismantle it. Sure enough, one of the inductors on the bottom had completely separated from the board. Now although I have good soldering skills, my iron is junk so it took a bit to get it resoldered, but I think I have it. I put it all back together and, well, I am typing this post from it now!

What a wonderful resource we have in the forum!

I finally attempted this....

I was successful on the first try, with the first board....but not so on the second board that I have. I'll have to unsolder the inductors on this second board, and try to re-do it. I might have messes it up though, because a small liquid ball of solder rolled over onto another chip on the board, and I wasn't able to get all of the solder off of it....

Well, it looks like I now have a working T23 (2647-4mu) available for sale....hehehe

Well done! - on the first board. As for the second..., you could try getting the solder off with a bit of solder wick or a solder sucker if you can get it in there. Otherwise, I'm after a T23 board for parts
Cheers

I have a third board that I might be willing to part with...unless I can't get the solder off of the second one.

I was thinking a few minutes ago that I might desolder one of the inductors off of the 2nd systemboard, and use it on the 3rd board, as that board is only missing an inductor...

What helps a lot is to first scrape the metal pads on the inductor to get rid of any oxidation. You need to get the pad shiny so that the solder bonds to it better. Once you get the pads cleaned, put a small bit of solder on each before attempting to afix it to the board (a process commonly referred to as "tinning" the connection).

Of course, if your vision is so bad that you can't even see the pads, then I can't help you .

Getting an inductor off can be just as hard as getting it on unless it's about to fall off. You have to gradually work the inductor off one side at a time. I have got myself a soldering tweezer that clams to the sides of the component and heats up both sides at the same time. Good luck but if all else fails PM me.
Cheers

Just wanted to add my 2 cents to this thread.

I had 2 broken off components and another component near the CPU (3 pins) had 1 pin separated from the board. I was only able to solder that loose pin because I only have a "big" soldering iron.

The 2 components in the back of the board were basically "pasted" back into place using a liquid called silver lacquer. After my first attempt I was jumping up and down, totally excited that I got my T23 to boot. The next time I built in the harddrive to start installation, again, no boot and the funny fan noise.

The second time, after putting the components in their place, waiting 24 hours to dry, I poured a very small amount of liquid silicone (the acid-free type) over the connected pins. Waited another 3 days for proper drying.

I am writing this post from my T23. Everything is working fine. I just won 1 GB of memory which I will be installing in the next few days. The only thing pending is the wireless LAN installation. I still need to get the antennae and the mini-PCI card.

Hope this gave an alternative to those who find it way too small to use a soldering iron.

Just got t23 w/ pulsating fan....
None of the above links seem to work
Does anyone have pix or saved unixnut's webpage???

Thanks

Never seen unixnut's web page, but this may help you:

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

Click on the "Bottom side w/legend" link and look in the area of D9 and E8.

If you are referring to my pics on the first page of this thread...try it again in a little bit. I see that Photobucket seems to be having issues, since I can't even get the main page to show up.

ok..
still no go with the first set of pix..
started to take laptop apart, and could hear some rattling inside..
after getting it all apart, out pops ??? (i have no idea what an inductor is)...........
anyway, looking at the scan of the motherboard, it appears to be the part located at D-9 and its labelled 5r2 N23 -- is the cause of the pulsating fan?

Now, do I just solder it back on???
What equipment will I need to buy??
Do I need to worry about orientation??
How do I do this without getting solder over everything else near it?

"5R2" should be located atop the two silver/copper pads on the motherboard at D9. In order to re-attach it, you will need a small soldering iron, rated at about 25 watts, the smallest, sharpest tip you can get for the iron, some small diameter solder (NOT acid core), good eyes and steady hands .

The orientation does not matter, other than to have the "5R2" facing up; there is no "polarity" to the inductor. Line up the metal pads on opposite sides of the part to the pads on the motherboard and apply heat. Feed a little bit of solder at the junction of the soldering iron tip, the pad on the motherboard and the metal cap on the inductor. If you are not skilled at soldering than I would recommend you find a friend who is as you can cause more damage (to the parts next to what you are replacing or applying excessive heat to the motherboard).

OK, the pics are working now...I forgot that I created a "Thinkpad" folder...

is there any solder "glue or paste"??? i think i could do one side of it, but the other is quite close to another component

Since it is an electronic component, it is not recommended to use paste. Here are some tips that I can give you:

1. Leave the PCMCIA carrier connected to the system board, so that when you turn the board upside down, it keeps it level.

2. It helps to have a third hand to add pressure to the top of the inductor, while you are trying to solder it.

3. Put the tip of the heated solder iron to the inductor, and THEN touch it with the solder. Since the surface is small, it will need to be heated before the solder will adhere. I had to resolder one of them 4 times, before I figured this out.

if I put a little solder on each pad, and then place the inductor over the solder. If I then heat the side plate of the inductor, would that heat up enough for it to melt? Would it damage the inductor?

ok, i've tried 3 times now... every time I think I have a good connection, when I take it apart, one side is lose

that's enough for me.................. anyone interested in the machine?


ok so I tried once more and IT WORKED!!!!!!!!!!!!!!!!!!!!!!!!

I love this site!

Yeah, it took me a few times to get it to work, and then a few times to get it to continue to hold.

OK.... now it will boot for several times in a row, and then won't ...
do i need to resolder the connection even though it feels good?

It might be worth doing it again...but hey...atleast you'll have lots of practice!

I have a few T2x series laptops with the same problem.

As soon as you turn the laptop on the fan spins up then spins down then spins up then down and just continues to do this.

Power light is on.

The screens do show backlight is good at times but not all the time.

Thank for any help.

Just noticed this thread and moved my post here.

Will remove the motherboard and and look into this choke.

Thanks all.

That’s it guys. By loosing the inductor coil the capacitor will constantly charge and discharge threw the circut. It looses the magnetism from the coil and can not maintain a constant voltage.

Under magnifying glass you can see corrosion. Not sure if this is from constant flexing or two dissimilar metals touching each other “Texas Interments had a problem with this in the 80’s”.

We have about 10-15 T23’s with this problem.

Will let you know how things turn out.

Thanks again.

Just finished #7 and have about 10 left.

Just wanted to tell everyone thanks.

Thanks again.

Phenomenon you are describing sounds like "black pad". Here's a very technical article about what this is:

SMT magazine article "Lead-Free Rework: Are You Ready?"

Appears to be one of the causes with the industry moving to lead-free assembly. I've simply scraped the pads on the part and board and removed as much as the black stuff as I can and re-soldered the component back on the board (and hope for the best).

I fixed one of these for a customer a couple weeks ago. He was very happy. Thanks!

Worked for me too! I had both the pulsating fans and battery charger issue within a couple of days of each other, the coil has even fallen to the base of my T23.
The charger problem was fixed by resoldering the battery connector pins, fuse and the nearby inductor.

Having inspected the fallen inductor it is apparent that there was a manufacturing process problem, most likely contributed to the material of the coil contacts not being treated properly and consequently the solder never got affixed to it.
Most likely this can be attributed to the individual components rather than the PCB itself (which is good news!) as the solder made a proper joint with the PCB itself.

What exactly was the charging issue with your T23? I have one that had the pulsating fan/ no boot and resoldered an inductor, which got the laptop working BUT it will not charge the battery at the full rate - it takes about a day and a half to fully charge. Also in winXP the charge indicator gets confused as does Battery Maximizer - it still thinks its on AC power even when it isn't. I don't have access to another battery to prove if the problem is in the battery or in the laptop, but I'm considering removing the motherboard (again) and soldering around the battery connector if that will fix this charging problem.

Welcome to thinkpads.com!

While I'm not sure if skydreamer is still active in the forums, my experience has been that a T23 which doesn't charge the battery is related to an inductor on the top side of the motherboard. If you refer to the thread that I started on T23 motherboard documentation:

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

click on the link for the "Top side w/legend". That will download a scan in which the inductor for the battery charging circuit is shown at G6. Not sure if a partially detached inductor there would cause your particular problem, but I'd check it just the same.

timgreg67, in your place I would not be too concerned about symptoms at this stage.
Instead, I would go through all the power inductors systematically.

I have just been through this, also on a T23.
Each time I thought that the machine was fixed, a new set of error symptoms came around and I had to open the machine again, just to re-solder yet another inductor.

There are 6 power inductors in total. So far, 4 of these have pop'ed off on my board.
The last one, which I re-soldered last night, was the one that Ray is referring to - L7 it is.
Put your nail below the inductor and push slightly in an upwards direction - see if the inductor comes off.