COD PAYMENTS ON ALL ON-STOCK CHIPS!

COD PAYMENTS ON ALL ON-STOCK CHIPS!

Quick guide for fixing "Battery Not Detected" Issue in Acer One 14 Z1402

February 12, 2019

We would like to share some ideas for resolving issues in Acer One z1402 where battery cannot be detected by the system. The troubleshooting concept here may be applicable to other laptops with similar charging circuit designs.

Symptoms:

  • Battery is not detected in Windows
  • Charging indicator does not lit

Repair notes:

  • BAT+ is normal and BAT_SMBCLK and BAT_SMBDAT have pullup voltage of 3.3V.  Also, no activity were noted in the oscilloscope.
  • Found an abnormal voltage reading in battery detector circuit, BAT_V = 0V
  • Pin 3 of Q58 is 0v which means BAT_V is forced to 0v. Expected voltage at this pin should 2.375V for normal operation. (see image)
  • Pin 2 has 3.3V which  should forces pin 6 and pin 5 to 0V. (see image)
  • But actual voltage at pin 5 is 5v which makes it abnormal
  • Further test indicates that D1-S1 junction is open which results in inconsistent reading of 5v in pin 5 and 0v in pin 3.
  • Replacement of Q58 fixed the problem

Battery Voltage Detector

Resolving cases like this can be easily fixed if every component will be checked for normal operation using datasheet or schematic diagram. However, analyzing the circuit and what voltage to expect as you test each pin of the IC is a difficult challenge. 

At leaky mosfet, we also provide advanced laptop repair training  for a limited number of serious trainees only.  Topics like these are explained in great details. Message us directly to know more about the training we provide.

Links:

Please like our page and share this post to spread the words.  

Level:

  • Intermediate to Advance





    Also in News

    Beginner's Guide to Laptop Repair

    May 22, 2020

     Seasoned repair technicians started from very little knowledge and evolved into what they are now. If you are planning to take this path as a part-time or full-time profession, there are few things that you need to keep in mind to get you started on the journey towards becoming a successful laptop repair technician.

    View full article →

    How to put Canon Printer in Service Mode (G2000, G2002, G2100, G2200, G2400, G2500, G2700, G2900)

    May 22, 2020

    Here is a quick guide to put the Canon printer into service mode.

    View full article →

    Acer V5-473 DAZRQMB18F0 w/ missing +5V_S5

    March 06, 2019

    View full article →