Power led flashing. Why won't it boot?

I suggest that you remove the battery and use the charger only in turning on your computer. If it turns on just fine without the battery then you would need to replace the battery. If it doesn't then it's either the motherboard or the charger which has a problem.
David

Try booting under AC power with the battery removed.

When you connect the power adapter into the laptop, does the power LED light up? If not then - The battery adapter or the adapter's power lead or the laptop's power socket could be faulty. Check power adapter's DC plug that connects into the laptop power socket with a multi-meter, the voltage should be slightly higher than the voltage that is printed on the label on the bottom of the adapter. If the voltage is zero or way below the voltage that is printed on the label then the power adapter is faulty and needs to be replaced. If the adapter is OK then connect it to the laptop and power it up, then look at the power/battery charging LED light and wriggle the power plug in the laptop's power socket. If the power/battery LED light flashes and in a certain position this LED light stays firm, then the power socket is either faulty or it has a dry solder joint where it is connected to the motherboard.

Whenyou connect the power adapter into the laptop, does the power LED lightup? If not then -The battery adapter or the adapter's power lead or the laptop's powersocket could be faulty.Check power adapter's DCplug that connects into the laptop power socket with a multi-meter, the voltageshould be slightly higher than the voltage that is printed on the label on thebottom of the adapter. If the voltage is zero or way below the voltage that isprinted on the label then the power adapter is faulty and needs to be replaced.If the adapter is OK thenconnect it to the laptop and power it up, then look at the power/batterycharging LED light and wriggle the power plug in the laptop's power socket.If the power/battery LED light flashes and in a certain position this LED lightstays firm, then the power socket is either faulty or it has a dry solder jointwhere it is connected to the motherboard.This can be repaired but itrequires the laptop to be completely dismantled to get at this power socket andrepair. If you cannot DIY then I suggest you get a quote first.

Check voltage at the charging socket of the scooter. The 2 outside pins.

A flashing amber power LED indicates that the power supply is not providing the correct voltage.

1. make sure if there is a voltage switch on the power supply that it is set to the voltage of your country (120 VAC for North America) maybe cycle the switch from 120 to 240 and back
2. If the switch is set right and you are using a power strip/battery backup, by pass it and plug directly to the wall.
3. Make sure the black and yellow 4 pin connector for the processor is connected on the motherboard.
4. if all the above have no effect, replace the power supply in the tower

Check the power adaptor led is not flashing. Flashing Adaptor LED indicates fault with laptop charging circuit / powerboard

If it will not boot on battery, and you know the adaptor to be good, the issue lies with the motherboard.
Sometimes, removing the battery, and unplugging, pressing the power button and holding it for 30 secs, replacing the adaptor only will allow it to boot up, but this will only work if the motherboard is not damaged r the CPU fan has not failed.

take a look:

Power Status Check
The following LEDs indicate the power supply status:
q Battery LED
q DC IN LED
The power supply controller displays the power supply status through the Battery and the DC IN LEDs as listed in the tables below.
Table 2-1 Battery LED
Battery LED Power supply status
Lights orange Quick charge.
Lights green Battery is fully charged and AC adapter is connected
Blinks orange (even intervals) The battery level becomes low while operating the computer on battery power.*1
Flashes orange The power switch is pressed on when the battery level is low.*2
Doesn't light Any condition other than those above.*1 Low Battery Hibernation will be executed soon.
*2 Low Battery Hibernation has already been executed.

Table 2-2 DC IN LED
DC IN LED Power supply status
Lights green DC power is being supplied from the AC adapter.
Blinks orange Power supply malfunction*3
Doesn't light Any condition other than those above.
*3
When the power supply controller detects a malfunction, the DC IN LED blinks and an error code is displayed.

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Error Code Check
If the power supply microprocessor detects a malfunction, the DC IN LED blinks orange. The blink pattern indicates an error as shown below.
q
Start
Off for 2 seconds
q
Error code (8 bit)


"1"
On for one second

"0"
On for a half second

Interval between data bits
Off for a half second

The error code begins with the least significant digit.
Example: Error code 12h (Error codes are given in hexadecimal format.)

Convert the DC IN LED blink pattern into the hexadecimal error code and compare it to the tables below.

q DC IN
Error code
Meaning
10h
AC Adaptor output voltage is more than 16.5 V.
12h
Current from the DC power supply is more than the limit (6.05 A).
13h
Current from the DC power supply is more than the limit (0.5 A) when there is no load.
14h
Current sensing IC is not normal.

q Main Battery
Error code
Meaning
21h
Main battery charge current is more than 6.05 A.
22h
Main battery discharge current is more than 0.5 A when there is no load.
23h
Main battery charge current is more than 3.1A when DC IN direct charge is off.
24h
Current sensing IC is not normal.
25h
Main battery charge current is more than 0.3A when the battery isn't being charged.

q S3V output
Error code
Meaning
40h
S3V voltage is not more than 3.14V when the computer is powered on or off.
45h
S3V voltage is not more than 3.14V when the computer is supports CV and is booting up.

q C5V output
Error code
Meaning
50h
C5V voltage is more than 6.00 V when the computer is powered on or off.
51h
C5V voltage is not more than 4.50 V when the computer is powered on.
52h
C5V voltage is not more than 4.50 V when the computer is booting up.
53h
C5V voltage is not normal when the computer is suspended.
54h
C5V voltage is not normal when the computer supports CV and is suspended.
55h
C5V voltage is not more than 4.50V when the computer supports CV and is booting up.

q C3V output
Error code
Meaning
60h
C3V voltage is more than 3.96 V.
61h
C3V voltage is not more than 2.81 V when the computer is powered on.
62h
C3V voltage is not more than 2.81 V when the computer is booting up.
63h
C3V voltage is not normal when the computer is suspended.
64h
C3V voltage is not normal when the computer supports CV and is shut down.
65h
C3V voltage is not more than 2.81V when the computer supports CV and is booting up.

q PPV output (PCU core voltage)
Error code
Meaning
70h
PPV voltage is more than 1.56V when the computer is powered on or off.
71h
PPV voltage is not more than 0.68V when the computer is powered on.
72h
PPV voltage is not more than 0.68V when the computer is booting up.
73h
PPV voltage is not less than 0.68V when the computer is powered off.

q BGVSNS output
Error code
Meaning
80h
BGVSNS voltage is not more than 1.62V when the computer is on or off.
81h
BGVSNS voltage is not more than 1.02V when the computer is powered on.
82h
BGVSNS voltage is not more than 1.02V when the computer is booting up.
83h
BGVSNS voltage is not less than 1.02V when the computer is powered off.
84h
BGVSNS voltage is not more than 1.62V when the computer is suspended.

q 1R5-E1V output
Error code
Meaning
90h
1R5-E1V voltage is more than 1.80V when the computer is powered on or off.
91h
1R5-E1V voltage is not more than 1.275V when the computer is powered on.
92h
1R5-E1V voltage is not more than 1.275V when the computer is booting up.
93h
1R5-E1V voltage is not less than 1.275V when the computer is powered off.
94h
1R5-E1V voltage is not more than 1.275V when the computer is suspended.

q 1R8-E1V output
Error code
Meaning
A0h
1R8-E1V voltage is more than 2.16V when the computer is powered on or off.
A1h
1R8-E1V voltage is not more than 1.53V when the computer is powered on.
A2h
1R8-E1V voltage is not more than 1.53V when the computer is booting up.
A3h
1R8-E1V voltage is not less than 1.53V when the computer is powered off.
A4h
1R8-E1V voltage is not more than 1.53V when the computer is suspended.

q 2R5-SNS output
Error code
Meaning
B0h
2R5-SNS voltage is more than 3.00V when the computer is powered on or off.
B1h
2R5-SNS voltage is not more than 2.125V when the computer is powered on.
B2h
2R5-SNS voltage is not more than 2.125V when the computer is booting up.
B3h
2R5-SNS voltage is not less than 2.125V when the computer is powered off.
B4h
2R5-SNS voltage is not more than 2.125V when the computer is suspended.

q 1R25-E1V output
Error code
Meaning
C0h
1R25-E1V voltage is more than 1.50V when the computer is powered on or off.
C1h
1R25-E1V voltage is not more than 1.063V when the computer is powered on.
C2h
1R25-E1V voltage is not more than 1.063V when the computer is booting up.
C3h
1R25-E1V voltage is not less than 1.063V when the computer is powered off.
C4h
1R25-E1V voltage is not more than 1.063V when the computer is suspended.

q 2R5-E1V output
Error code
Meaning
D0h
2R5-E1V voltage is more than 3.00V when the computer is powered on or off.
D1h
2R5-E1V voltage is not more than 2.125V when the computer is powered on.
D2h
2R5-E1V voltage is not more than 2.125V when the computer is booting up.
D3h
2R5-E1V voltage is not less than 2.125V when the computer is powered off.
D4h
2R5-E1V voltage is not more than 2.125V when the computer is suspended.

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In the case of error code 10h or 12h:

Make sure the AC adaptor cord and AC power cord are firmly plugged into the DC IN 15 V socket and wall outlet. If the cables are connected correctly, connect a new AC adaptor and/or AC power cord, if necessary.

In the case of error code 2Xh:

Make sure the battery pack is correctly installed in the computer. If the battery pack is correctly installed, replace the battery pack with a new one.

If the error still exists, the system board or the battery board may be disconnected or damaged. Disassemble the computer and check the connection between the AC adaptor and the system board and connection between the system board and the battery board (if there is one, in my case it was integrated to ths system board).

After checking the connection, perform the following:
Check 1
Replace the AC adaptor with a new one. If the AC adaptor is still not functioning properly, perform Check 2.
Check 2
Use a multimeter to make sure that the F8800 fuse on the System board is not blown. If the fuse is not blown, go to Check 3. If the fuse is blown, go to Check 6.
Check 3
Use a multimeter to make sure that the F1000 fuse on the Battery board is not blown. If the fuse is not blown, go to Check 4. If the fuse is blown, replace the Battery board with a new one following the instructions in Chapter 4.
Check 4
Make sure that the Battery board cables are firmly connected to PJ8820 and PJ8821 on the System board and to PJ1000 and PJ1001 on the battery board. If they are connected firmly, go to Check 5.
Check 5
The Battery board or System board may be damaged. Replace it with a new one following the instructions in Chapter 4.


I hope this helps many people with the troubleshooting. Details may vary as models vary, but most if it is the same for every Toshiba

If the laptop battery is more than 3 - 4 years old then the battery could be worn out. Rechargeable batteries have a finite number of charge and discharge cycles and will lose their charge capacity over time, until they won't charge up at all.
Check power adapter’s DC plug that connects into the laptop power socket with a multi-meter, the voltage should be slightly higher than the voltage that is printed on the label on the bottom of the adapter. If the voltage is zero or way below the voltage that is printed on the label then the power adapter is faulty and needs to be replaced.
If the adapter is OK then connect it to the laptop and power it up, then look at the power/battery charging LED light and wriggle the power plug in the laptop's power socket. If the power/battery LED light flashes and in a certain position this LED light stays firm, then the power socket is either faulty or it has a dry solder joint where it is connected to the motherboard.
This can be repaired but it requires the laptop to be completely dismantled to get at this power socket and repair. I suggest you get a quote first.

Try this

1. Remove the battery and the AC adapter. Hold down power button for 5 seconds. then insert the AC adapter only and see if you can power up the laptop. if it does power up, dont use the Battery anymore as it might be the cause of the problem