how annoying.. [IBM thinkpad]
So I bought the replacement motherboard from eBay, and all seemed well with
the machine running for around 10 minutes. I closed the machine and left it to recharge its battery. When I came to switch on, it wouldn't fire up, and I could hear funny noises which I suspect was the hard drive beign powered on/off at something like 2hz. After a bit of playing, it seems that this board is now dead also, except that on this one the power and activity (hdd) lights are flickering very quickly, and about one-third brightness. Could there be a logical explanation for what might be damaged? Perhaps some kind of capacitor which is needed to hold a charge and allow it to power-up? What can I test with just a multimeter? I have since noticed that the PSU is over-rated, at 4.5amps instead of the machines stated 3.5A, but I thought that the additional current was simply not used. Could this have been the cause of the problem? I have now tried a more closely matched thinkpad PSU (3.36A), and it does the same. thanks for any help. |
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 |
how annoying.. [IBM thinkpad]
"carl0s" wrote in message ... I have since noticed that the PSU is over-rated, at 4.5amps instead of the machines stated 3.5A, but I thought that the additional current was simply not used. Could this have been the cause of the problem? 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. I have now tried a more closely matched thinkpad PSU (3.36A), and it does the same. thanks for any help. 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 |
how annoying.. [IBM thinkpad]
"Dave D" wrote in message ... 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. 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!! |
how annoying.. [IBM thinkpad]
"carl0s" wrote in message ... There isn't a light on the PSU, no. 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 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!! Oh, it's always worse when it's someone else's appliance! Good luck. Dave |
how annoying.. [IBM thinkpad]
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. People complain if you sell something as-is when you insist that it works, but then they want you to warrant their mistakes. carl0s wrote: 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!! |
how annoying.. [IBM thinkpad]
"Mike Berger" wrote in message ... It sounds like there's a good chance that it was fine until you messed with it. 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 hope you explain that to the Ebay seller too. I told him it ran for 10 minutes, pretty much like I said here. People complain if you sell something as-is when you insist that it works, but then they want you to warrant their mistakes. 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. |
how annoying.. [IBM thinkpad]
"carl0s" wrote in message ... 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 |
how annoying.. [IBM thinkpad]
"Dave D" wrote in message ... "carl0s" wrote in message ... 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. |
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