Acer Aspire one D270 Turning Off in Second After Pressing Power Switch

[mygemsga2019]

Please help to troubleshoot Aspire One D270.

After Pressing power On the LED indicator goes On and Goes OFF right away. Bios Voltage is present 3.3V so as the Power switch. No Short in Main Power rail.

Here's my issue the Voltage in PU3 is not Normal it says different from the schematic. I don't know the reason and how to solve the issue. Please see the Voltage in PU3 below.
1. 0.8 v
2. 0v
3. 2v
4. 0v
5. 0v
6. 0.4v
7. 3.4v
8. 3.4v
9. 8.2v
10. 3.4v
11. 3.4v
12. 0v
13. 3.1v
14. 0v
15. 0v
16. 19v
17. 5.2v
18. 3.4v
19. 0v
20. 5v
21. 0v
22. 8.7v
23. 1.2v
24. 5.2v.

Do I need to replace the chip or if there is another way around to solve the issue. Thank you to all

[mcplslg123]

Re: Acer Aspire one D270 Turning Off in Second After Pressing Power Switch

Entrip2 at 0.4V is too low(pin6). Without having voltage at FB1/FB2 you wont have output on 3v/5V coil. Vreg3/vreg5 are ok. There are other anomalies like gate voltages but those can be looked later. Check all the resistors connected to Entrip and FB pins. If all seems okk, replace the IC.

[mygemsga2019]

Re: Acer Aspire one D270 Turning Off in Second After Pressing Power Switch

Hi mcplslg123, Thank you for the reply. There's only 1 resistor connected to PU3 Pin6(PR69) which I think faulty(70k ohm), it is so suppose to 4.7k Ohms. So I replace it with 5k ohms if that would be Okay? But same thing happen still not powering on. So I decided to reheat the PU3 and boom its working. I'm so glad that I fixed this one. Running for 2 hours now I wish that theres no other issue. Thank you for the help highly appreciated! I will update the status later once everything's fine. Stay safe!

[mygemsga2019]

Re: Acer Aspire one D270 Turning Off in Second After Pressing Power Switch

Update: Running for few hours now so far no issue...

PS: I forgot to mention in my previous comment that I also replaced PC58 caps with Tantalum caps

[mygemsga2019]

Re: Acer Aspire one D270 Turning Off in Second After Pressing Power Switch

Update: After 7hours of Testing the unit suddenly shut off. When I switch On again the issue is back. Battery charging indicator is still ON. Any input please to solved this issue. Thank and stay safe!

[lapfix]

Re: Acer Aspire one D270 Turning Off in Second After Pressing Power Switch

Replace PU3

[mygemsga2019]

Re: Acer Aspire one D270 Turning Off in Second After Pressing Power Switch

Replace PU3

@lapfix Thank you. I replaced PU3 once the IC arrived already ordered. I will update this thread after I replace the PU3. Thank you and Stay safe!

[mcplslg123]

Re: Acer Aspire one D270 Turning Off in Second After Pressing Power Switch

Update: After 7hours of Testing the unit suddenly shut off. When I switch On again the issue is back. Battery charging indicator is still ON. Any input please to solved this issue. Thank and stay safe!

I had this doubt when you said on heating PU3 it worked. There is likely to be broken internal connection inside the ic which is temporarily restored due to heating. Always replace the IC in such scenario-else it'll keep coming back to you at regular intervals.

[mygemsga2019]

Re: Acer Aspire one D270 Turning Off in Second After Pressing Power Switch

I had this doubt when you said on heating PU3 it worked. There is likely to be broken internal connection inside the ic which is temporarily restored due to heating. Always replace the IC in such scenario-else it'll keep coming back to you at regular intervals.

@mcplslg123
I replaced the PU3 and tested the unit. And after 11 hours the unit restarting itself I thought It was just okay since it is working again but after several hours the unit turned off. Try pressing the power it will Turn on for several minutes then turn off again.

Is the PU3 Faulty again?

[mcplslg123]

Re: Acer Aspire one D270 Turning Off in Second After Pressing Power Switch

Could be PU3 faulty but could be some thermal trigger issue and can even be a dying atom cpu.

[mygemsga2019]

Re: Acer Aspire one D270 Turning Off in Second After Pressing Power Switch

I will replace again the PU3 hope it works.