• Lenovo B450 power problem

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Lenovo B450 power problem

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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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 This topic is marked as ARCHIVAL. Please only reply if your message contains the solution (Terms and Conditions p. 12.1).

#1 Lenovo B450 power problem

by cygron • 4 June 2024, 15:11
Model : Lenovo B450
Board id : 09244-1 LA14 Dis MB 48.4DM04.011

Problem is laptop can't switch on. There is no 3V 5V output on coils L6 and L15. U22, U23, U28, U29 and U20, U21 all are ok. There is no short on 3V5V output line. Voltages to ground on U47 are

Pin 16 (Vin) - 19.5V
Pin 8 (VREG3) - 3.3V
Pin 17 (VREG5) - 5V
Pin 13 (EN0) - 1.6V
Pin 23 (PGOOD) - 0V

I also change to test U47 (TPS51125). But the same.

Sometimes laptop automatically open when connect DC Powersupply but no display. Power comsumption on DC Supply is about 1.1 amp. All coils except L30 have voltages. Press power key for some seconds, laptop is off. But can't open again. Need help.

Re: Lenovo B450 power problem

by Google Adsense [BOT] • 4 June 2024, 15:11

#2 Re: Lenovo B450 power problem

by Lesio23 • 4 June 2024, 15:36
Witam,

Programowałeś bios ? Jeśli nie to od tego bym zaczął.

But can't open again.

Czy na włączniku jest napięcie 3.3V i po naciśnięciu spada do 0V?

#3 Re: Lenovo B450 power problem

by cygron • 4 June 2024, 15:47
I haved flash 3 bios file from some internet source. But problem still exits.

Yes, voltage have on switch and drop to 0 when press power key.

Re: Lenovo B450 power problem

by Google Adsense [BOT] • 4 June 2024, 15:47
 This topic is marked as ARCHIVAL. Please only reply if your message contains the solution (Terms and Conditions p. 12.1).
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