Re: Hp Probook 455 G3 DAX73AMB6E1 blinking charge light, not turning on
Alright, it's not going to give up its secrets that easily. So when you get your power supply, it's going to go as follows:
- Set a voltage limit of 3V.
- Start current limit at 0.
- Either clip the ground lead to a screw hole at the edge of the board, or solder a wire to a suitable ground point and clip the ground lead to the wire instead.
- Solder a wire to the PL12 pad that still measures as shorted (or reattach PL12 and solder directly to PL12 itself), and then clip the positive lead to that wire.
- Slowly ramp up the current.
The actual voltage shouldn't even reach your limit since the resistance is too low. But it will edge up slowly as the current increases.
We don't know where the short is, so we don't know how much current will be required to find it. If a small component (like a surface mount capacitor) is shorted, then it won't take much power to get it hot. But if a larger chip is the culprit, then it might take a lot more to get it warm.
I'd say set it to 100mA. And if everything looks good, starting moving it up to 500mA, 1A, 1.5A, etc. At each level you must touch every single little component (including the tiny surface mount parts) on the board to see if they are getting warm.
If you narrow the warmth to a small area, but can't decide which component is the source of the heat, you can use drops of isopropyl alcohol. The warmest spot will be where it evaporates first.
No heatsink is required during this test.
Alright, it's not going to give up its secrets that easily. So when you get your power supply, it's going to go as follows:
- Set a voltage limit of 3V.
- Start current limit at 0.
- Either clip the ground lead to a screw hole at the edge of the board, or solder a wire to a suitable ground point and clip the ground lead to the wire instead.
- Solder a wire to the PL12 pad that still measures as shorted (or reattach PL12 and solder directly to PL12 itself), and then clip the positive lead to that wire.
- Slowly ramp up the current.
The actual voltage shouldn't even reach your limit since the resistance is too low. But it will edge up slowly as the current increases.
We don't know where the short is, so we don't know how much current will be required to find it. If a small component (like a surface mount capacitor) is shorted, then it won't take much power to get it hot. But if a larger chip is the culprit, then it might take a lot more to get it warm.
I'd say set it to 100mA. And if everything looks good, starting moving it up to 500mA, 1A, 1.5A, etc. At each level you must touch every single little component (including the tiny surface mount parts) on the board to see if they are getting warm.
If you narrow the warmth to a small area, but can't decide which component is the source of the heat, you can use drops of isopropyl alcohol. The warmest spot will be where it evaporates first.
No heatsink is required during this test.
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