LENOVO IDEAPAD 100 works only on bench power supply

[rabsonnjala]

Hie I have a Lenovo laptop
Lenovo Ideapad 100-14IBY AIVP1-AIVP2 LA-C771P rev 1.0
it's working only on the bench power supply when I put the battery it doesn't power on. when I also use the original charger it doesn't power. the batter Is fully charged, I used another laptop to charge the battery. but when I use a bench power supply it works perfectly

below are my readings

with the original charger only
JBATT1
PIN1 0.22V
PIN2 0.22V
PIN3 0.45V
PIN4 0.45V
PIN5 O.43V
PIN6 0V
PIN7 GND
PIN8 GND

JDCIN1
PIN1 19.8V
PIN2 19.8V
PIN3 GND
PIN4 GND
PIN5 0V

Other Voltages
+3VALW Not present on the Power button and other areas


with the original charger and battery
JBATT1
PIN1 11.23V
PIN2 11.23V
PIN3 0.45V
PIN4 0.45V
PIN5 O.43V
PIN6 0V
PIN7 GND
PIN8 GND

JDCIN1
PIN1 19.8V
PIN2 19.8V
PIN3 GND
PIN4 GND
PIN5 0V

Other Voltages
+3VALW Not present on the Power button and other areas




with the bench power supply only @ 20V 1.5A
JBATT1
PIN1 0.22V
PIN2 0.22V
PIN3 3.03V
PIN4 3.03V
PIN5 2.90V
PIN6 0V
PIN7 GND
PIN8 GND

JDCIN1
PIN1 19.8V
PIN2 19.8V
PIN3 GND
PIN4 GND
PIN5 0V

Other Voltages
+3VALW Not present on the Power button and other areas
+3VALW measuring 3.03V on the Power button but on the battery connector is 2.90v




with the bench power supply only @ 20V 1.5A with battery
JBATT1
PIN1 12V
PIN2 12V
PIN3 3.03V
PIN4 3.03V
PIN5 0.16V
PIN6 0V
PIN7 GND
PIN8 GND

JDCIN1
PIN1 19.8V
PIN2 19.8V
PIN3 GND
PIN4 GND
PIN5 0V

Other Voltages
+3VALW Not present on the Power button and other areas
+3VALW measuring 3.03V on the Power button but on the battery connector is 0.16v

bech power supply reading
with battery connected
when the motherboard is On 20V 0.761A
when the motherboard is off 20V 0.02A

without battery
when the motherboard is on 20V 0.146A
when the motherboard is off 20V 0.016A


i have also noticed that when i switch on the motherboard while battery is connected and remove the charger the motherboard is still powering on from the battery. but if i want to power on the motherboard directly from the battery without the power supply nothing happens

[mon2]

Re: LENOVO IDEAPAD 100 works only on bench power supply

Hi. Is the other working laptop the same model?

[rabsonnjala]

Re: LENOVO IDEAPAD 100 works only on bench power supply

yes same model

[mon2]

Re: LENOVO IDEAPAD 100 works only on bench power supply

1) having the other working laptop may come in handy to service this one by comparing voltages.

2) remove all power (no adapter / no battery). Meter in resistance mode (2k should be ok).

Check each mosfet for defects / shorts as follows:

resistance between source & drain
source & gate
gate & drain

start with the first mosfet @ PQ201.

So you will be placing,

one meter probe on pins 5-6-7-8 (drain) & other probe on 1-2-3 (source) - value ?

then, 1-2-3 (source) & gate (pin 4) - value ?
finally, 5-6-7-8 (drain) & gate (pin 4) - value ?

Repeat again for testing PQ202, PQ203 (battery fet - important one to check), PQ204, PQ205.

Post the readings for each mosfet.

Good reference material on this topic:

http://electronicsbeliever.com/how-t...0good%20MOSFET.

The table on this webpage is gold.

[ktmmotocross]

Re: LENOVO IDEAPAD 100 works only on bench power supply

pin 3 , 4 of batrtery is 3V comunicating lines.