I have a LENOVO IDEAPAD 310-15ABR (mb CG516 NM-A741 Rev 1.0). Replaced kbc and pmic an reflashed bios and EC bios. Everything works fine except for the fact that the fan starts slow and then approaching booting it goes to almost full speed and stays there. This fan has 5 wires and I've observed that if i get my hand progressively closer to said fan, it speeds even more, and the increase in speed is proportional to how close my hand is (mobo and fan on my workbench outside the rest of the laptop).
Used an oscilloscope and i can see the speed increasing there.
Using the scope I can see...

Lenovo Ideapad 310-15ABR CG516 NM-A741 Rev 1.0...

no luck my friend, I used the values you gave me at post #18 but regardless of everything ok (setup shows correct sn and all), fan still does the same. 1st time using hex editor and it was easier than I thought. Thanks for your help....

Ive read it with a svod 3. The mb wasnt even turning on...

hi there, badcaps web rejected the bin format, I see you uploading as .rar, will do the same with the original bios. I dont know if I understand what to do with yours. I can tell you that I've already downloaded that bios from the lenovo site, and updated it within windows. In the process it updated the ec bin too....

first of all thanks [USER="201805"]peste[/USER]. I should have taken more care in my description of the problem

Here's the data:

[url]http://support.lenovo.com/qrcode[/url] S/N:PF0QUJXF MO:PF9XB7407059 MTM:80ST0087AR


I should add some observations i made:

1- This MB works just fine except for the fan speed problem? Loads windows and everything else.

2 - The fan starts at slow speed and then accelerates when entering boot selection

3 - The signal EC_FAN_PWM starts modulating ok, and then goes to 3v at...

hello! I've succesfully replaced and flashed my EC (thanks a lot btw), but now the fan runs at full speed and never stops (except obv. when powered off). This laptop came to me not powering on, had to replace EC, pmic and reflash corrupted system bios (I have the original dump). Any hints?

Hello I'm Hector from Argentina, glad to join in, eager to share info, but I'm a newbie at laptop repair. Cheers