• Lenovo Lenovo V145-14AST power on but no display

It is currently 6 April 2025, 17:12

Lenovo Lenovo V145-14AST power on but no display

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  1. Topic title should contain: the device's manufacturer, full model and the brief description of problem.
  2. Topic message should contain: the PCB marking code (required in case of hardware repairs), an extended description of problem, things you have checked/replaced/measured, your conclusions and the question. If you are not able to find the PCB marking code, please read THIS TOPIC. If you still cannot locate the PCB markings, please upload a clean, both-side photos of the mainboard - it is required to remove any films, modules or brackets possibly covering these markings.
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#1 Lenovo Lenovo V145-14AST power on but no display

by cygron • 6 March 2025, 09:03
Model : Lenovo V145-14AST
Board id : DLADE ELAV4 V5 LA-G241P REV 2.0

Laptop came with blowned mosfet PQ801. I aslo found open mosfet PQ740. After replace all damage mosfet, laptop is running but no display (picture). All coils have voltage.

PL402 - 3.3V
PL404 - 5V
PL803 - 0.85V
PL804 - 0.95V
PL602 - 0.97V
PL502 - 1.2V
PJ804 - 2.5V
PJ802 - 1.8V

And I notice that when connect adapter, 5VALW, 3VALW, 1.8VALW, 0.95VALW are not comming. These volts only comming when i press power key. I alreadey flash bios and ec. But problem still exit. Need help.

Re: Lenovo Lenovo V145-14AST power on but no display

by Google Adsense [BOT] • 6 March 2025, 09:03

#2 Re: Lenovo Lenovo V145-14AST power on but no display

by tekort • 6 March 2025, 11:03
The PQ801 MOSFET delivers power directly from B+ to the APU, so if it got shorted, there is a great possibility of damaging the APU. The only hope was that the main MOSFET PQ740 broke in time to save the CPU, but I suppose that PQ801 got burned and then PQ740 - most often fault.

What is the current consumption of the board?

#3 Re: Lenovo Lenovo V145-14AST power on but no display

by cygron • 6 March 2025, 14:10
I don't think APU is damage. Because when i replace damage mosfets and laptop running fine once. When i shutdown laptop and reopen again it open but no display (picture).

Current consumption of the board is about 0.500 amp. I notice that when laptop running fine, PL803 is about 1.1V and current consumption is about 1.2 amp.

#5 Re: Lenovo Lenovo V145-14AST power on but no display

by cygron • 7 March 2025, 14:40
PU2001
pin 2 - 3V
pin 3 - 3.37V
pin 4 - 5.1V
pin 6 - 1.8V

PU2002
pin 2 - 3.37V
pin 3 - 3.37V
pin 4 - 5.1V
pin 6 - 2.5V

PU501 pin 4 and pin 20 have 0.6V

Re: Lenovo Lenovo V145-14AST power on but no display

by Google Adsense [BOT] • 7 March 2025, 14:40
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