Thinkpads Forum

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Does it boot with the battery removed?

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Could you have disconnected the DC jack from the motherboard while you were removing the heatsink/fan? And failed to re-connect? Did the repair shop open your ThinkPad up to check things out, or did they just charge your battery in the other machine?

I am not sure where this connection is located. Would it be possible for this to be disconnected and the computer still recognizes when the jack is inserted? The computer recognizes when plug is in and out. It willl even say that the battery is charging when it is plugged in.

Also, are thinkpads supposed to be able to run without the battery installed?

Thanks - I really appreciae your help.

IIRC, the connector is right next to the heatsink/fan on the top right side. But I doubt that the OS could tell the difference between plugged in and not if the jack was disconnected. So that's probably not the case here.

Yes, ThinkPads can, and do, run just fine without a battery installed. I often operate some of mine that way.

You just might have some damage to the power management circuits on the system board. It's not all that difficult to break one of those tiny surface mounted components loose, or even completely off. There was a thread on the forum recently where someone had done just that very thing while removing a keyboard, I think it was.

Hopefully, someone else will come along with a better idea, and solution to the problem.

Hi guys, I just picked up my laptop from the shop - they said it was the motherboard. Is there any way to troubleshoot the power circuit? I don't have a charged battery - so I have absolutely no juice.

My computer definitely does not run with the battery out. I will take it apart and take some pictures, maybe you guys may see something.

Thanks for the help.

What model ThinkPad is this anyway. I've re-read the thread and I just don't see any indication of what we are dealing with here. Other than the section the topic is in, that is.

Sorry about that - it's a T500.

Just a few minutes ago I was reading this thread about similar issues, and trouble shooting the T43p motherboard:

http://forum.thinkpads.com/viewtopic.php?t=70832

If it was me, with an older model, I would just replace the board rather than spend hours searching for a fault on the board, that I probably couldn't repair anyway. Just so happens I'm working on a T41 right now that will run off of battery or AC, but won't charge the battery. But a replacement board is cheap enough that I won't waste my time trying to fix the one that is installed. With a T500 I just don't know what a board would go for, or how much difficulty you will get into trying to find the fault. There are others on this forum that could provide more help, I'm sure.

I can't get the camera to take a decent picture tonight - will try again in the morning w better light.

I've taken it apart as far as removing the heat sink and can't find anything phsically wrong. No unplugged connectors and all the wires seem to be OK.

Through some of the recommended threads, I've been turned onto the fact that there are fuses on these boards. Are these fuses located on the underside of the board? I can't seem to find anything labeled "F."

I've also read that if the charging circuit is fried that it takes the motherboard with it. This was really dissapointing. If anyone can verify this I will start the search for something new, I may be about to give up on this. I am not an electronics or circuit guy. I would like to try and fix it though.

There are fuses on both sides of the board. You may need a magnifier to read the "F" label that is on some of them (I do - 5X). And you will probably have to get the board completely out of the base in order to locate them. I have tried in the past to solder a new fuse, piggy-back, over a blown one and just could not do it. They are just too tiny for me to handle.

And, yes, as that thread I linked above shows, blown fuses are not the only culprit in these cases. It might just be a blown fuse, but it might also be that one or more tiny IC chips are bad. All these parts are surface mount, and extremely difficult to remove or replace.

Best bet, is to just replace the motherboard. Or sell what you have for parts, and look for a completely new system.

Bummer...

What would be the best way to sell parts for a laptop? This is all completely new to me.

Easiest way would be to place an ad in the "Market Place" section of this forum. Just give the seven character type number for your machine, what all you will be including with it and an accurate description of the problems you are having. List it with an asking price...whatever you think it's worth in the condition it's in. If you don't know what it's worth, set a price anyway, and list it as asking that price, or best offer. Very likely, someone here will be interested in taking it off you hands. Different folks use computers in different ways, and someone might be able to use it just like it is. You might even decide you have a use for it, even with it's shortcomings.

Another way is taking it completely apart. Down to individual parts, and selling the parts either here or on eBay. It's more work that way, but often yields a few dollars more.