W520 requires 170W AC adapter

[hellosailor]

If you mean the correct able with the drop-down resistor in the end fitting?

AFAIK that's only sold integral to the power supply. It does not unplug. So unless there's some oddball source for these, you'd have to buy a standard plug and add the resistor yourself. Or lop one off of an older power supply that wasn't working.

One day my computer surprised me with a "wrong power supply" message. It turned out that the plug had just worked out of the socket, just a little bit. And despite the message, the computer kept working just fine.

[KMantas]

I wish I knew about this issue before and haven't thrown away old cable :/ where is that resistor? is it in the plug or in that thicker part which is ~20 centimeters before the plug?

[hellosailor]

I can't swear how Lenono does it, but the resistor is usually installed "in" the plug, or at the point where the cord enters it.

USB devices all use the same logic, with a drop-down resistor added into the plug to signal different types of cables. And resistor values chosen by the device maker, not set on any universal standard.

[axur-delmeria]

It's soldered to the terminals of the plug before the rubber sheath is molded.

It's not hard remove the sheath and solder the resistor-- the big problem is how to put the sheath back on.

If the plug itself doesn't heat up much, it may be possible to use hot-melt glue to make a new sheath. I've done something similar, but it was a 3.5mm stereo headphone plug, not a 135/170w power connector.

You might have to research DIY silicone rubber injection molding techniques.

[KMantas]

thanks for replies

I'm thinking what would happen if I just connect outer shell with center pin.
In the chart I see
0 Ω = 135 W barrel

so maybe it will that it is 135W charger and it is going to work?

[KMantas]

got it working - put some resistor. but I think it should work without it also. Will try next time if it breaks again

[jcvjcvjcvjcv]

thanks for replies

I'm thinking what would happen if I just connect outer shell with center pin.
In the chart I see
0 Ω = 135 W barrel

so maybe it will that it is 135W charger and it is going to work?

I believe you can do that mod inside the Thinkpad.

[axur-delmeria]

I believe you can do that mod inside the Thinkpad.

Isn't this dangerous, disconnecting the center hole on the DC jack, then soldering a resistor and connecting it to ground?
Now it won't be able to detect the actual wattage of the adapter. :O

[jdrou]

I believe you can do that mod inside the Thinkpad.

Isn't this dangerous, disconnecting the center hole on the DC jack, then soldering a resistor and connecting it to ground?
Now it won't be able to detect the actual wattage of the adapter. :O

That depends on what the consequences are of getting too little current from the adapter. Most likely either the laptop won't run, will run at lower power state, or will drain the battery (if the adapter is current-limited) OR the adapter will overheat and shut down. None of those should cause physical damage AFAIK. A no-name adapter from China could certainly be a problem though so I wouldn't use one of those with such a mod (if at all).

[jcvjcvjcvjcv]

I believe you can do that mod inside the Thinkpad.

Isn't this dangerous, disconnecting the center hole on the DC jack, then soldering a resistor and connecting it to ground?
Now it won't be able to detect the actual wattage of the adapter. :O

Just a direct connection between center hole and ground if I remember right. That should make the laptop think a 135W PSU is connected whenever a PSU is connected.

Let's face it: W520 does not support that super fast charging. With light use you are never crossing that 90W, even when charging.

That 170W is designed around

The 170W requirement is for a fully populated and utilized W520 with the 2000M GPU, the i7-2920XM processor running flat out at 3.5GHZ TurboBoost, all controls at maximum performance, 16GB RAM, all USB and eSataP ports utilized. The power demands in that scenario will exceed 135W, hence the need for the 170W supply.

https://forums.lenovo.com/t5/W-Series-T ... m-p/556067

+dock I guess.

[san40k]

This thread was very helpful to get to know my "new" w530, wasn't aware of all the 90W/170W differences and oddities.

So far i did strip the notches in round power tip of 170W adapter using accidentally fitting Husky 8-in-1 Torx Screwdriver with torx bit removed. Now other 90W thinkpads and 90W mini dock 4337 can be powered by 170W brick.

Quad core W530 runs a lot hotter and louder than T*30 dual core models. I'm not surprised, but it would be nice to find ways to control temp/power more flexibly.

[hellosailor]

I think that part of the "hotter and louder" problem has to do with the NVidia graphics processor (GPU) on the W530. There was an issue with them overheating, maybe 5 year ago, and the not entirely wonderful "fix" was a software patch that IIRC both slows down the GPU, degrading the graphics performance, and changes the threshold for the system fan, keeping the GPU cooler.

I've even been surprised to find the fan kicking on when I'm not doing anything graphics-intensive, and I'm using an SSD so there's certainly no heat from the hard drive. And the CPU is lightly tasked. So...the Nvidia problem.

I'm also finding Winodws10 seems to have some issues with the graphics system, every one in a while it kicks the desktop/color scheme into odd places and it refuses to recognize the normal old controls to reset them.

The computer is also quite happy with a 90W power supply--as long as you're not pushing it. It may complain that's the wrong supply, but it can certainly run with it.

[san40k]

I found a solution for loud fans since my post: changed windows 10 CPU cooling policy from Active to Passive, its' in advanced settings of Power Options: "Processor power management > System cooling policy"

I have not measure effect on performance, but i suspect it would be same under heavy load, while quiter and hotter under idle load.

Do you mean a modded 90W adapter (with resistor or short in power tip)? For me standard 90W doesn't work (ie W530 doesn't boot without battery), seems to be only running from battery with 90W

[hellosailor]

Yes, I ran mine on a 90W adapter, although for me that means "resuming" from sleep, not a stone cold boot. Battery was not discharging, don't remember if it was charging.

Bear in mind that for every 10C that the ambient heat increases, the working life of electronics is cut in half. Yes, it is that big a difference. So if the change in fa policy allows the system to run just 10C (~20F) hotter....it is doubling your chances of the CPU, GPU, memory, etc. failing. I'd rather go with aggressive cooling, personally.