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Paper Tape
Posts: 2
Registered: ‎09-01-2017
Location: GE
Views: 457
Message 1 of 2

Thinkpad T420 65W Adapter not enough anymore

In this post I would like to share my recent discovery regarding T420 Adapter. 


Two months ago after installing several updates from Windows 10, I noticed that my laptop has slowed down tremendously. It had problems even for loading web pages like facebook and youtube. So, I started looking for the problem. I reinstalled windows and flashed in fresh new Windows 10, but still the problem was there. Then changed my RAM but still the problem was there. Then I changed my Hard disk from ordinary one to Samsung SSD, but still the laptop's performance was only 1/100 of what it is capable of. Once, totally accidentally, I stared using my laptop on the battery and that all the problems dispappered. The laptop was working like brand new, opening up and running any apps as fast as it was doing originally. And that was when an idea strcuk intow my head that it could be the problem related to the adapter. Then I bought 90W adapter and bum, all the problems were solved and my laptop work perfectly fast as beofore. 


When workng on 65W original adapter it was running always from 35% to 100% utilization rate and the speed of the processor was always stuck at 0.79 never changed.  Even when I am not dong anything and the laptop is idle utilization rate is 32% and speed is always 0.79. 























As for when working on Battery, utilizatio rate is changing and max it reachs is like 60% and speed goes up to 3.20. When idle and not doing anything speed is somehere around 1.2 and utilization rate hovers around 1-3%. 

























My wild guess is that new BIOS (1.52)  that I updated sometime ago, requires high power for the processor to work properly and that is why now only 90W is working well. 


Here are some additional infor about my laptop. 


i5-2520M(2.5GHz),6GB RAM,256 Samsung EVO840 SSD,14in 1600x900 LCD,Intel HD Graphics,CDRW/DVDRW,Intel 802.11agn wireless,WWAN option,Bluetooth,1Gb Ethernet,UltraNav,Secure Chip,Camera,6c Li-Ion,Win10 Pro 64


Can somebody who is more techie and who knows more in detail about thinkpad T series comment his/her opinion about this issue and whether my guess is correct or simply the processor is dying? Smiley Happy 

Posts: 9
Registered: ‎08-02-2018
Location: GB
Views: 424
Message 2 of 2

Re: Thinkpad T420 65W Adapter not enough anymore

To test the CPU you can use Prime95 from mersenne.


Check your power plan settings and ensure max CPU Utilisation is at 100% on abttery and mains.


You could just have a faulty charger - I have seen faulty chargers cause issues similar to this on my T530.

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