W520 ISSUE / The connected AC adapter has a lower wattage

[dtbsz]

Hi guys.

Any opinions on the following:

http://forums.lenovo.com/t5/W-Series-Th ... ight/false

Thank you in advance!

PS: I'm not trolling or luring people away to another forum. I'm just in need of help. Thank you!

[Greg Gebhardt]

Which adapter are you trying to use? I get a warning if I use my slim 90watt but it work just fine. I think even my 135 watt gives me a warning but you can't tell a difference. I do not suggest the 90 watt if you are doing intensive CPU and video but I bet the 135 watt will do just fine!

[dtbsz]

Which adapter are you trying to use? I get a warning if I use my slim 90watt but it work just fine. I think even my 135 watt gives me a warning but you can't tell a difference. I do not suggest the 90 watt if you are doing intensive CPU and video but I bet the 135 watt will do just fine!

The one that came with the laptop. 170W. Didn't you read the discussion on the linked page?

[Greg Gebhardt]

No I am loyal to Thinkpads.com and could never be swayed to leave here.

[dtbsz]

http://dl.dropbox.com/u/7483846/ac-adapter.jpg

[davidhbrown]

There is a signaling scheme used for power adapters (a little like how monitors tell you video card what they can do). Sounds like (hopefully) the chip in your power adapter is wonky... if not, it's the computer's. Warranty service an option?

[dtbsz]

There is a signaling scheme used for power adapters (a little like how monitors tell you video card what they can do). Sounds like (hopefully) the chip in your power adapter is wonky... if not, it's the computer's. Warranty service an option?

Thanks for the tip and yes I have International Warranty. Also called support, I just have to take it in for them to test and see.

BTW. Any ideas on how they will test this? Could I do this alone? What equipment would I need?

[davidhbrown]

The consensus on the thread at lenovo's site does seem to be that the power circuitry on the main board is the culprit, necessitating warranty service.

You can test most things that involve two components yourself by having an extra of at least one component.

If you connect the same adapter to two W520s (same BIOS) and only one W520 complains, the problem is probably in the computer. If you connect the same adapter to two W520s and both complain, the problem is probably in the adapter. If you connect two adapters to one W520 and it complains only for one adapter, it's probably the adapter. If you connect two (170W) adapters to one W520 and it always complains, it's probably the W520.

You can change "probably" to "almost certainly" if you can do both tests -- that is you can get your hands on both a spare W520 and a spare power supply -- and the results agree.

[dtbsz]

Thank you captain obvoius... I'm getting the machine back from service this week. They say the error didn't show up while they tested it and they changed the charger, but if I experience the problem again, it's 99% that it's the motherboard.

[Colonel O'Neill]

It happened to mine twice on two consecutive warm reboots. A shutdown, adapter/battery detach, power button tap, reattach, boot fixed it and it hasn't happened since.