Hello, I have a pcb from an e scooter which had a faulty diode but even after removing it from circuit, it still has a short to ground on the three components circled. I have removed every cap on the board and tested one by one and the short is still there and all the caps test ok. Could this be because I haven’t put a diode back on it yet or where do I go next please?
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check the regulator -
Before that, disconnect any cables connected to the board.
Inject the low voltage and see which component is getting hotComment
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Which one is the regulator please?Comment
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Also, when injecting voltage where would I put the positive wire in the picture please?Comment
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kia117 is a regulator, so is the 6pin chip
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How can I check it and in what mode on the multimeter pleaseComment
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Which pins on the regulator do I test to see if it’s shorted please and in what mode on the multimeter also in or out of circuit?Comment
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Thank you where is 3.3v pleaseComment
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There is a continuous beep between 12v and ground pin you pointed out in the picture.Comment
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check between the 3 pins on the 117, if any combination beep then remove it and test again.
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Do I test from ground plane to each pin of the 117?Comment
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Clearly, this regulator is giving 3.3V on the output. Check now between ground and the output, then between ground and the input on the 1117 regulator. See which one shows lower resistance. Or, try injecting a low voltage on the VIN, VOUT, or the 12V line. Any component on the board that takes high current will heat up quickly. Or you can use the multimeter in ohm mode to find the pin that gives the lowest resistance to ground. That's all.Attached FilesComment
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So I test between ground and the input leg of 117 in resistance mode right?Comment
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Hi,
I have an iMac with the power supply reference: ADP-200DFB.
This power supply is not working and when trying to debug the problem with a multimeter, I found what I thought to be a short circuited diode (the short-circuit is to ground).
With the continuity test it beeps both ways, so doesn't block current flow at all then reverse biased. But after removing the diode the beep continues and the diode seems healthy. It seems to exist a real short-circuit.
As I have another ADP-200DFB power supply (faulty one as well), I have checked the same... -
Hi All.
I have an 820-02016 board (A2337 M1) that has come in for data recovery. Reported as liquid damage, but no visible evidence of any liquid damage.
Board was initially stuck at 5v, and current only spiking occasionally to around 400mA and cycling.
After initial troubleshooting, found that C7800 (which feeds the power rail PP5V_BSTLQ_VOUT_SPMU) was dead short to ground.
Replaced C7800 and short gone. Board still stuck at 5v. Current draw behaviour changed. It now spikes up for a second to around 100mA to 130mA, then drops down to... -
Hi everyone,
I'm having a serious issue with my ASUS Zephyrus GA401I (4 years old, worked perfectly until recently). The system is lagging heavily, even in the BIOS, and is charging extremely slowly (a few percent in hours), making it nearly unusable. I suspect a motherboard or power delivery issue.
Symptoms:- Severe lag across the system, including BIOS navigation.
- Slow boot times and unresponsive performance in Windows.
- Battery charges very slowly (e.g., ~5% in 2–3 hours).
- No error messages or BSODs, just extreme sluggishness.
What I've Tried:- Replaced
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Hi everyone,
I'm having an issue with my Lenovo ThinkPad P43s. The laptop does not power on when the internal battery is connected, but it works fine on AC power alone (battery disconnected). Once the battery is reconnected, the system becomes completely unresponsive — no lights, no fan spin, nothing.
Here's what I've tried so far:- Power/EC reset (held power button for 60 seconds with battery and AC disconnected)
- Booted successfully on AC power only with the battery disconnected
- Visual inspection of the battery — no swelling, burn marks, or connector damage
- Battery
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