How to use a small 90W power adapter with a ThinkPad W530

power supplythinkpad

I have a Lenovo ThinkPad W530 computer. The 170W power adapter it comes with is huge!

I tried to plug in an old 90W adapter — which is much smaller — to the computer but immediately when it starts booting an error message appears:

 The connected AC adapter has a lower wattage than the recommended
 model which was shipped with the system. To boot with the AC adapter,
 please connect the AC adapter which was shipped with the system.
 Press Esc to continue.

When I boot up the system I see that the computer is running on battery.

Is there some way I can power my computer with the old standard ThinkPad 90W adapter?

Comments about answers

Yes, there are ways to achieve this, but they require a little hardware work.

The computer seems to use the resistance between two points on the adapter tip to determine which adapter it is. By manipulating this resistance the computer can be made into thinking a 90W adapter is one it can accept. The internet reports that this works fine unless the computer is under very heavy load.

I will post the two ways that seem easiest to me myself. I do this to get the information available on this site. I only found it after searching for it for a long time on the Lenovo discussion forum, which I find rather hard to navigate.

The ThinkPad W520 has the same issue.

Best Answer

The following is what seems to be the simplest solution. I have tried this myself and it seems to be working fine, but I can't myself judge whether there are any problems with it.

User Tamazerd posted this solution on the Lenovo discussion forum:

I used a small jump wire from a kit i had but anything will do. Just make sure it wont short against anything else!

I located where the middle pin of the power-plug is connected to the motherboard (blue cable) and used the jump wire to bridge it with one of the ground/negative ones (black).

This works good for me so far. The only problem i can see with this is if the computer now thinks that all adapters are 135W ones, even the 170W adapter. This is something i havent been able to check.

WARNING: Modifying electric equipment might be dangerous! Do this on your own risk and only if you know what you are doing.

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