Hello everyone! I've came here to seek for wisdom of more experienced people. The problem I have with my motherboard ASUS 5pg41-m lx is that there is a short somewhere and for the love of God i can't find it. There is one specific mosfet that burst every time when I replace it. There are 8 of them around the CPU and it's always the same one, the other ones always survive. I thought that my CPU was shorted at first, but after changing 3 CPU-s, the problem is still the same. I did found one shorted capacitor but that was it. Has anyone maybe came across the problem like this or had similiar experience. I would like to hear your opinion on this matter. Here are some pictures. There is flux on the board from resoldering mosfets on the motherboard. The circled mosfet is the problematic one. Also the two wires coming form the motherboard are connected to a capacitor, it couldn't fit between the coils so I just put it little above(that was the shorted one).
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Re: Need help about motherboard fixing
Maybe your VRM conrolller is damaged (or mosfet driver if it uses) and keeps the mosfet high all time, some boards can boot even with one phase removed (use low power CPU in this case), i would remove the mosfets of the problematic phase and check if it boots.
You can also check the gate with a DSO and compare with other phases. -
Re: Need help about motherboard fixing
I think that I found the problem. The component in question is epu asp0905b. I was touching the components while the mobo is connected to a psu and this component gets really hot. It's probbably in short circuit. I've orderd a new one from aliexpress. It was really hard to find.
I tried it withouth one "phase" and it still doesn't boot.Attached FilesComment
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Hello everyone, I recently found this badcaps site and super Learn Electronics Repair youtube channel. And I wanted to learn how to troubleshoot power supplies and VGA cards and how to practice soldering, since I already have a properly defective piece of them. I am currently trying to solve two problems:
I have a Gigabyte GV-RX460WF2OC-4GD type card. I managed to find the faulty MOSfet (AON6414A) on it, which I replaced. The card starts up, but after about half a minute, the MOSfet in the same position will be shorted again. Is it possible that the PWM controller driving the MOSfet... -
I've got an old Alienware M18x R1 which shorted out the charger whenever it was connected. Tracked down the short to two shorted caps and burned CPU power controller caused by a shorted mosfet on the CPU's graphic power supply.
I've replaced the faulty mosfet, two shorted caps and the CPU Power controller (NCP6151S52MNR2G).
Issue is now whilst there is no short if I attempt to power the system on the fans spin for a couple seconds there are no lights and no further action - the PCH is heating up but there is no CPU power coming out but there is an enable signal... -
I am trying to fix an iMac 2017 PSU, initially came with a blown fuse and shorted PFC MOSFET (6R199P). After visual inspection and some measurements I replaced the FET with a P20NM60 and tested with 100w series lamp, and it lasted 1 second before going into dead short. The PFC controller chip (NCP1605BG) and its passives appear fine (passives measure OK), but I do not know if there is a simple way of testing the NCP1605 as I wouldn't like to blind-replace it.
There was some slight blackening of the solder on the PFC controller passives so I reflowed them all with some flux. I am waiting... -
Hi All,
I have this MSI GTX-980ti Gaming Golden Edition. It had shorted mosfet on memory. Replaced the shorted i.e. Q47 PK616BA with 4C09N and the card ran fine for a month. Then suddenly again the same problem. This time when i replace it 4C09N or with replacement PK616BA (Aliexpress) it gets shorted. As soon as turn on the PC the PSU shuts down and the same mosfet Q47 gets short.
What should be the next step. Kindly guide.
The board view files for this gpu is available and attached. https://www.badcaps.net/forum/showthread.php?p=1237952... -
I tried to use this method:
Testing an N-channel MOSFET:
Step 1: Discharge the Gate (turn off the MOSFET)
Place the black probe (COM) on the Source (S) and the red probe on the Drain (D). The multimeter should show no continuity (high resistance or "OL" – open line).
Then, touch the black probe to the Source (S) and the red probe to the Gate (G). This discharges any stored charge in the Gate, turning the MOSFET off.
Step 2: Charge the Gate (turn on the MOSFET)
Now, place the red probe on the Gate (G) and the black probe on the...09-27-2024, 03:31 AM
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