How To Solve Usb Port Not Working Problem In Laptop Motherboard
The trick to solve LENOVO G50 motherboard part no. - nm-a272 All USB not working Problem.
Problem - LENOVO G50 motherboard part no - nm-a272 All USB port not working Problem.
CASE STUDY BY
Laptex Family Member
Troubleshooting - As per Discussion in LAPTEX-Laptop Repairing Training Course if USB not working then need to check the working of the USB IC.
The basic Working philosophy of any IC, in general, is that:-
1) Power Supply (VCC, VDD, etc.)
2) Enabling Supply (EN, CS, etc.)
3) Output Supply (Vout, ALW, PCU, etc.)
This Lenovo G50 model with SKU part no. nm-a272 was already tampered by some other technician for the same problem. Also, he changed the SIO or controller IO but the problem not solved.
NOTE - No need to change SIO in this case, as a USB communication is directly related to the HUB, PCH or Chipset so the doubt should go to the enabling input from PCH and not on SIO as per discussion in the online laptop repairing training module.
Steps to solve this problem
1) I checked all the USB jack 5 VOLT VCC which is needed for USB to work was missing. First I changed this IC but the problem not solved.
2) Then i checked the requirement of the USB power IC. It's 5 VOLT input was ok but output voltage not coming.
3) I Checked IC ENABLE volts on pin no 4, instead of 3.3 volts it was dropped to 1.67 volts. It means IC not ENABLE to provide output.
4) Then, I traced the ENABLING supply and found it was coming from PCH. It was confirmed that in the track path it was getting dropped somewhere. So, I decided to put a jumper wire from the output of PCH to the enabling input of the USB IC.
5) I removed the USB power ICs and made a direct connection to the ENABLE pin via a jumper. The
problem was solved and USB ports working normally.
Complete Basic to Advance Chiplevel Laptop Repairing Training Course -
1) Online Laptop Repairing Training Video Course.
2) Offline Laptop Repairing Training Course.
3) Advance Case Study Online Video Course.
Call or WhatsApp
Nasir - +919871145066 Dildar - +919031240767
Address - LAPTEX 605-A, 58-Sahyog Building, 6th Floor Nehru Place New Delhi Pin-110019 India.
Disclaimer: We are not authorized service center of hp dell acer Lenovo and apple we only repair/sell out of warranty laptop and use 100% compatible parts.
All product names, logos, brands, trademarks and registered trademarks are property of their respective owners!!!