Between ground and output measures 0.828K ohms and ground to input measures 51.8k ohms.
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On the pcb where do I put the red and black wires to inject voltage with a power supply?Comment
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You need a bench power supply with adjustable voltage and current. You just can’t put “some” PSU on it and plug it in.Comment
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I have an adjustable power supply also I have removed and measured the two 514 resistors and they measure at 0.510milliohms, is this what it should be or are they bad please?Comment
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Also, when measuring both pads when they beep both sides this is the readings I get in the picture.Attached FilesComment
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- First, what's the resistance between the 12V line and ground?
- Second, is the 12V line connected to the point where you measured 3.1 ohms? (continuous beep)
- Third, if the resistance between the 12V line and ground is low, inject 1 or 2V into the 12V line and monitor the current draw.
If it draws more than 1A, the shorted component will heat up within seconds...
If the current draw is low at 1 or 2V, gradually increase the voltage until it reaches 1 or 1.5A.
Attached FilesComment
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The resistance between 12v line and ground is 2.4ohms and yes the 12v line is connected to the point where I measured 3.1ohms, also while injecting voltage could I use IPA on the pcb to spot the component that gets hot as I don’t have a thermal camera or electrical frosting spray.Comment
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Thank you, I have soldered the black wire to ground and red wire to 12v but when I checked for continuity to make sure they were soldered on properly both the ground and 12v get continuity through the black wire, is this how it should be or should the 12v be getting continuity through the red wire as the red wire is the one going to the 12v?Attached FilesComment
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what is U3 ?Comment
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I unplugged the connector that leads from the board in the picture attached to the board that had the short to ground and now the short to ground has gone so I assume that it’s an issue with the board in the picture attached but where should I look or test on this board?Attached FilesComment
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hello everyone , working zebronics power suply 450 watts , 5v ,3.3v givin short to ground black wire, also in circuit at output, resistor was charred but shows right values , after removing resistors 39ohms, 51 ohms, there was no short , no continuity beeps with ground , but after replacing new resistors (now i am not switching it on) ,again short still exists . when i put bigger ohm resistor like 100k ohm , no short beeping sound comes , lower ohm resistor gives continuity beeps ,other big ones donest , as its a working psu , i am confused what to remove now or how to go further now .
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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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Hello everyone,
I'm currently diagnosing a MacBook Pro A1707 motherboard that does not power on. I've gathered some data but am stuck and need expert advice.
Note that i'm a beginner in electronics and i'm trying to learn while trying to repair this macbook that my work gave me. I'm really curious and love understanding how thing works and i already learned so much.
Only one usb c port is taking 20v and have 12.5v on PPBUS_G3H. when trying other ports, 2 are not going to 20v and one is going to 20v but the CD3215 is getting really hot.
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Hello everyone,
Firstly sorry for my english, french guy inside.
I brought a macbook pro A1708 - 820-00840 logic board, wasn't powering on.
History is a day, nothing happened when opening the laptop.
Nothing special inside, no corrosion, no liquid damage, never opened.
First, with the logicboard alone on the desk, mesures are :
5v017 and 0.000 amp. nothing else.
Finding a short on the PP3V3_G3H_VR, but not on the PP3V3_G3H (0.540 on diode mode), PPDCIN_G3H_CHGR_R present (5,1 volts) PPVIN_G3H_P3V3G3H around 4.1 volts. PM_EN_P3V3_G3H...
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