T23 almost fried-no battery operation

[stockzguy]

My T23 just experienced the following. I loaded MS Excel, using my CDRW-DVD. Everything was fine until a week later. The ultrabay was only clicking and did not recognize a CD/DVD. I removed it and reinserted it. Same problem. What happened next is I started to get a burnt electronics smell ( I know it well) and my LCD screen started fading. I immediately pulled the power from the laptop, which I saved from total destruction. Now the laptop only works on AC power, not the battery. The battery appears (new one too) dead also. The unit will not charge any battery either. Is there a charging circuit that can be replaced or is it incorporated into the MB? Is there a fuse that controls the battery operation and charging that can be replaced and where is it located as I checked the pdf T23 manual from IBM and cannot find it. The laptop runs great except you can only use it (yuck) on AC power. Are 2647 4MU parts compatible with a T23 2647 8MU? (Mine) T23 2647 8MU XP Pro

[rkawakami]

Hang on a second... I'm in the middle of manually sniping a couple of things on eBay . For now, here's a thread you can read:

http://forum.thinkpads.com/viewtopic.php?t=37956 (T23 motherboard information and images)

edit: Okay, now that the eBay business is out of the way...

The charging circuit is part of the motherboard and cannot be independently replaced. It consists of an IC and related components. There IS a fuse which protects the battery and is located on the top size of the motherboard at map location G6. It's the white block with silver endcaps at the very bottom corner of G6. Also inside that area is an inductor which works itself loose and one of the symptoms is that the battery doesn't charge anymore, although I believe that the laptop can still be powered by the battery (if the fuse is still good).

The 8MU and 4MU should use the same motherboard. At least that's what the HMM says.

The burning smell may not be good news. I'd carefully inspect the tops of each component, top AND bottom sides of the motherboard, and see if you can see anything which has either a burnt spot or hole.

[stockzguy]

Ray, the CDRW-DVD in the ultrabay went first and something else occurred along with it. I'm not sure what it was, but most of the fried electronics was from the CDRW-DVD drive. What I'm not understanding is why/how the MB took all this and is still operating like nothing occurred, except for the battery operation. Do you have a link to the location of the fuse. Is it worth my time to bring this to someone for an estimate to see what's wrong, or just buy a new MB from Ebay and replace it?

[Jax184]

I'd be willing to bet your motherboard is toasted. A battery fuse popping wouldn't cause a burning electronics smell and the LCD fade out. Interesting that it works as much as it does now though...

Anyway, I have a spare T23 board which may or may not work perfectly. I bought it to replace one that had the loose inductor problem before I knew about it. When it arrived, it too was dead from the same problem. I've since resoldered the inductors on both it and the original, but never tested this one. Cost me $50 too...
If you want it, I'd love to regain some of that wasted money.

[rkawakami]

What I'm not understanding is why/how the MB took all this and is still operating like nothing occurred, except for the battery operation.

Same here. The last time a T23 motherboard emitted smoke resulted in a completely dead system (ref: my "hole" link in my first post).

Do you have a link to the location of the fuse.

Also in my first post. The T23 motherboard information thread contains two links to images of the top and bottom side of the motherboard. The main fuse is located on top, in grid location G6. It's a Littelfuse part which can be obtained from either mouser.com or digikey.com. I've posted that info previously but I'll poke around in a minute or two and see if I can dig it up. Here it is:

http://forum.thinkpads.com/viewtopic.ph ... 965#214965 (sorry, had the wrong one there for a second...)

Is it worth my time to bring this to someone for an estimate to see what's wrong, or just buy a new MB from Ebay and replace it?

Your call. I'd say that if you take it in to have component level repair performed, that it would cost you more than a known good motherboard you could probably get off of eBay.

[stockzguy]

rk, I didn't mention this-there was not any smoke at all, as soon as I got the smell of near-burning electronics and my LCD screen starting "melting" I pulled the power cord. No smoke at all, which is a 'good' thing as I have not backed up all of my work and I need another (3rd one) CDRW-DVD ultrabay drive. Except for the AC operation only problem, the laptop is working flawlessly. I am not sure what will occur when I insert a new CDRW-DVD into the slot, as something may be causing a short.

[rkawakami]

Sorry, I read into your earlier description that some "magic smoke" was in evidence; my mistake. If the smell you refer to is that one which is associated with burning plastic compound of an IC package, then I know it well too . If you do find that the fuse is blown, then replacing it may not solve your problem. Typically, a fuse will expire due to a short as you suspect. If that short still exists, putting a replacement into the circuit just means another chance to sacrifice a fuse, or something else. I have a T23 that had a blown fuse protecting the DC input. I briefly inspected the board and replaced the fuse but the first and only time I powered it back up, I started smelling something familiar. So I yanked the power and put it on my shelf for another day.