Case Study : Dell Laptop
Part No : QAL80 LA-7781P
Problem : No Display
Solution : Found that only stuck in 0.150 amp on PSU. Step down Ic (3.3 v /5 v ) heating.
Checked For short Circuit Not Found. Then checked the RTC 3.3 v it was 0 volt Replaced RTC Cell Then Also no voltage RTC. At Last Found Pf Leaky
Laptop Working Fine
Showing posts with label Board Repair. Show all posts
Showing posts with label Board Repair. Show all posts
Wednesday, January 3, 2018
Tuesday, January 2, 2018
Acer Aspire E5-573 No Power On and Not Charging
Model:Acer Aspire E5-573
MB ID:ZRT
Case Study Problem : plugged in adaptor no power on and not charging
Solution : First I check VIN present, no auxuliary voltages at battery connectors.
I check with PSU 19V, it takes 0.28amp then decrease voltage from 19v to 17v.
now the laptop power on and working fine. So the problem is located at the power IC pin(6) 2.59v (acdet).
I check voltage divider working ok as in schematic
Now I replace 8k resistance in place of 10k now am getting voltage is 2.13v (63.4k-10k actual)
ok i give 19v from PSU ...LAPTOP is working fine.
MB ID:ZRT
Case Study Problem : plugged in adaptor no power on and not charging
Solution : First I check VIN present, no auxuliary voltages at battery connectors.
I check with PSU 19V, it takes 0.28amp then decrease voltage from 19v to 17v.
now the laptop power on and working fine. So the problem is located at the power IC pin(6) 2.59v (acdet).
I check voltage divider working ok as in schematic
Now I replace 8k resistance in place of 10k now am getting voltage is 2.13v (63.4k-10k actual)
ok i give 19v from PSU ...LAPTOP is working fine.
Labels:
Acer Laptop,
Board Repair,
Boardlevel,
Laptop Repair,
No Power On,
Not Charging
Friday, December 29, 2017
Old Motherboard Auto On and Can't Save Time
Old Motherboard Auto On and Can't Save Time
Problem: Auto on and can't saved time even though it was replaced with a new CMOS battery.
Action taken: Check crystal oscillator no luck, resolder frequency generator no luck, check two 22pf 1 is shorted so have to replace.
Problem: Auto on and can't saved time even though it was replaced with a new CMOS battery.
Action taken: Check crystal oscillator no luck, resolder frequency generator no luck, check two 22pf 1 is shorted so have to replace.
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