Lenovo Thinkpad X220 i5 power cables to motherboard query

[j909]

Lenovo Thinkpad X220 i5 power wires to motherboard query

I lost my charger, and have another charger with a different adapter plug, so i going to hardwire this charger bypassing the laptops socket.

entering my motherboard has 5 wires: 2 black, 2 red, 1 blue

my charger cable has 3 wires: 1 black, 1 white, 1 blue

how do i wire these 5 to 3 wires together??

[RealBlackStuff]

2 red = +20V (most likely your white)
2 black = ground (most likely your black)
1 blue = sensor wire for charger capacity 65W/90W/135W/170W (most likely your blue)
Inside the Lenovo barrel-plug there can be a resistor from sensor-middle-pin-->ground.
For 65W: 10 kΩ
For 90W: not connected
For 135W: 0 kΩ
For 170W: 1.5 kΩ
If you don't connect blue-to-blue, the X220 will assume your [oddball] charger is 90W.
Make sure its output is 20V.

No guarantee for 'your' black/white/blue wire correctness!

[j909]

thank you for the reply Real,

the charger i am using is a HP 120watt.
19.5volts, 6.15amps.

so i am going to connect:
- the 2 Black wires to the black charger wire
- 2 red wires to the white charger wire

?? - the blue wire to the blue charger wire ??

[RealBlackStuff]

Use a Multimeter to check which HP wire is 'life', I assume it's the white.
And there's no need to connect the blue wire (X220 will Think it's 90W).
X220 can happily live with anything from 65W and up.
And the 19.5V is OK too.