how annoying.. [IBM thinkpad]

If you unplug the PS and take out the battery and then replace will it turn on? I had something similar to that happen to my thinkpad (390X)

never got it fixed though

nope, I've tried all permutations of that sort of thing.

No. As long as the voltage is identical and the current capacity is equal or greater, it will be fine. The laptop will draw whatever current it needs, and a larger capacity power supply is in fact a bonus- it *should* run cooler and last longer.

Laptops generally slow-charge the battery when powered up, and fast charge the battery when powered off. This is because of the limitations of the small power supplies. It sounds like something on the motherboard was damaged while charging the battery, possibly the battery itself has an issue- maybe that damaged your old motherboard? It's impossible to say without proper diagnostic procedures.

You'll need some considerable experience with SMT rework, the necessary tools and access to what are often specialist components if you are to be able to sort this out yourself, a multimeter and a soldering iron aren't enough.

Is there a light on the power supply? Does it dim when the laptop is misbehaving? It sounds like the laptop is drawing too much current, or the power supply voltage is too low.

Dave

Thanks for taking the time to reply Dave. I have been considering buying one of those SMT rework stations from eBay for some time.. but even so, I don't know enough about circuits and transistors to really get anywhere. I don't even know how to identify what most of these SMT components are. I'd love to have a clue though..

There isn't a light on the PSU, no.

oh well. I've gone back to the eBay selling saying it's faulty, but perhaps as you say it is the battery which has killed it :(

Wouldn't be so bad if I wasn't doing this for someone else!!

Perhaps you could come up with a way of monitoring the power supply's output voltage while trying to power up the laptop? The voltage shouldn't vary by more than a fraction of a volt.

Oh, it's always worse when it's someone else's appliance! Good luck.

Dave

It sounds like there's a good chance that it was fine until you messed with it. I hope you explain that to the Ebay seller too.

Pe> oh well. I've gone back to the eBay selling saying it's faulty, but perhaps

Well you could be right, but it seems at least a little unlikely. The PSU is, or appears to be good, and everything else is onboard, including the CPU and RAM. The only other possibility might be the battery, but I've never heard of a battery pack having some kind of intermittant short through all the cells (the battery, and everything else, was running ok for the ten minutes.)

I told him it ran for 10 minutes, pretty much like I said here.

Sure, and it is an auction at the end of the day, but it's sold as working and I'm not exactly trying to have him over. I have asked if I can meet him half-way on a replacement, since he does have a few more up for sale.

Did you wear an antistatic wristband while installing it? Was it supplied in an antistatic bag?

Dave

Yes and yes.