Model number is NM-F311 KE611 / KE451 Rev 1.0
Amp meter without battery is the same: 0.224~
It appears that what's heating up is on the other side of the board is the BQ chip. BQ25710? Or it's BQ25730? It is hard to read. PU4000 about 60 celsius. This heats up when battery is connected, might be normal.
bialag
Member
Last Activity: 04-09-2025, 09:59 AM
Joined: 12-12-2017
Location: Winnipeg, MB
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Lenovo ThinkPad E14 Gen 5 - Not Powering On - 3 Blinking Lights - 20 volts 0.224 amps
Hello,
I have a Lenovo here that does not want to power on. The motherboard appears to be clean, no sign of corrosion or obvious fried components. When plugged in, I see 3 blinking lights and then off. It would cycle the 3 blinking lights every 10 seconds or so as long as I have the adapter plugged in. Amp meter shows 20 volts, 0.224 amps, no fan spin, red light indicator near the charge port.
Thermal camera shows a section of the motherboard that is warmer than the rest. It is near the connector labels JRTC1 (CMOS battery). Diode measurement to ground for pin 1 = OL,... -
Re: Acer Nitro 5 AN517-52-5744 - Not Powering On
I injected 1v and did not see anything until I raised it slowly to 2v and then 3v. I found PU301 to heat up quite a lot. What chip is this? I also see pin 2 of this chip is about to break off.Leave a comment:
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Re: Acer Nitro 5 AN517-52-5744 - Not Powering On
That makes sense. Should I inject 1V into +19VB and see what gets hot? I do have a thermal camera that should help as well.Leave a comment:
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Re: Acer Nitro 5 AN517-52-5744 - Not Powering On
Oops.
PDB1
1. 9.45K
2. 1.5 Ohms
3. 282KLast edited by bialag; 05-15-2023, 03:02 PM.Leave a comment:
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Re: Acer Nitro 5 AN517-52-5744 - Not Powering On
I measured PDB1 with battery and PSU disconnected and this is what I get:
PDB1
1. 0.309
2. 0.00 *
3. 1.579
Pin 2 is shorted to ground and battery is not connected.Leave a comment:
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Re: Acer Nitro 5 AN517-52-5744 - Not Powering On
I measured in diode mode:
DC-in 1.575
MOSFET
1.442
1.442
1.442
1.233
1.574
1.574
1.574
1.574
I also found pin 2 for PDB1 (+19VB) to be shorted to ground?
PDB1
1. 0.309
2. 0.00 *
3. 1.579Leave a comment:
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Re: Acer Nitro 5 AN517-52-5744 - Not Powering On
Alright it might look like the DC-in might have something to do with it. I instead injected 19.5 volts directly after the DC-in jack and now I get 19.5 volts but still 0 amps. EMI coils have 19.5 volts on both sides and the 3 pin dual common cathode diode is now outputting 19.5 volts to the BQ chip.
I put together the motherboard and other components but unable to turn on by pressing the power button. The MOSFET near the DC-in jack shows 19.5 volts going in pins 1,2,3,4 and 0v going out pins 5,6,7,8.Leave a comment:
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Re: Acer Nitro 5 AN517-52-5744 - Not Powering On
Hello,
I checked and both sides of the coil is 3.3 volts. Please see attached. I noticed PL102 (below PL101) was burned and so I removed. I have not replaced it yet, but 3.3v still remains on both sides of the coils. I also tested continuity from the DC-in jack where it meets the power adaptor and pin 1 that is soldered to the motherboard. Tests fine yet it is measuring 3.3 volts from ground....Last edited by bialag; 05-15-2023, 12:00 PM.Leave a comment:
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Re: Acer Nitro 5 AN517-52-5744 - Not Powering On
Thanks for the quick reply.
1. 3v
2. 0v (+19VB)
3. 3.3v (+19V_VIN)
This is consistent with the 3.3v coming from the main AC-in pin and I'm for sure getting 19.5v from the power supply.Leave a comment:
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Re: Acer Nitro 5 AN517-52-5744 - Not Powering On
Hello, here are the voltages. A lot of these seem very low.
1. 0v
2. 0v
3. 0.290v
4. 0.270v
5. 0v
6. 0.410v
7. 0.010v
8. 0.250v
9. 0.530v
10. 0v
11. 0.020v
12. 0.010
13. 0v
14. 0v
15. 0.010v
16. 1.280v
17. 0.141v
18. 0.900v
19. 0.133v
20. 0.133v
21. 0.490v
22. 0v
23. 0v
24. 0.375v
25. 0.470v
26. 0.152v
27. 0.141v
28. 3.09vLeave a comment:
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Acer Nitro 5 AN517-52-5744 - Not Powering On
Hello guys,
I have a Nitro 5 motherboard that is not powering on. When I connect 19.5v from the power supply, I get 3.3-3.8v where the charging port AC-in is supposed to be. For the supply and gate of the MOSFET I get the same 3.3-3.8v and at the drain 1.3v. The 3.3-3.8v jumps up and down with and without the MOSFET installed.
There is also a PQB11 where I get 1.3v at pin 1 and 0v and -15v for the other pins.
All this with 0 amps being drawn. Any ideas?
Board number: FH51M LA-J871P Rev: 1B 2020-06-04... -
Re: Microsoft Surface 7 + UEFI lock
Hello, I need help with my Surface Pro 7+. Basically it turns on to Surface logo and after a second turns off. I get roughly 2-2.2 volts on the BIOS chip when I press the power button then it power cycles down. I followed instructions to analyze ME region and no issues have been detected, but I went and cleaned the ME anyways. Here are the two files, can someone help? I have a few other Surface Pro 5's that are doing the same as well. After soldering the BIOS chip back on, the behaviour is still the same. Turns on, Surface logo, turns off....Last edited by bialag; 05-03-2023, 02:51 PM.Leave a comment:
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