i need to know what does q505 (is near the max psu chip/ right side edge of the board top side ) power cause the mosfet shorted out while i was working on it i need that info so i know what to check in before i replace the mosfet and burn it out again i removed the mosfet already it was a ao4194 and the short is gone from the charger port and no more heating in that area (i guess the mosfet was the only short )
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Last edited by dragos2009; 05-23-2020, 05:13 PM.
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Hi all,
I have recently picked up this Dell OEM Nvidia GTX 750Ti 2GB Video card. Its an old card I know but still wanted to get it working if possible. The problem is the following:
- Put the card in my testing motherboard and start running Heaven benchmark
- Benchmarks seems to run smoothly up until half way then the motherboard completely shuts off immediately
- Try to start it again and I get a slight move from the PSU fan - a clear short
- A little troubleshooting later I find one shorted Mosfet - Replace them both - short is gone
- Put the... -
Hi,
My laptop went dead and after checking ,the main 19 volt power rail was shorted. After some checks i could identify that a high side vcore mosfet was shorted.
I replaced the mosfet and now the white powerled is present , fans start spinning but capslock shows the famous 5 long and 3 short code.
I checked the vcore voltages after replacement and i get for all 1.01 V so means for me that the driver is still working of the replaced shorted mosfet. On the Nvidia i measure around 0.8 V after the mosfets.
I did voltage injection on the cpu with 0.7V and i have a current... -
I got this laptop from friend with problem short 19v....when i check this 2 mosfet getting short...i remove that mosfet and confirm that mosfet is short...
and check that 2 capacitor PC9009 and PC9004 pad is also short...already check where that capacitor goes and came from but cannot find the main problem...please help
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Looking for guidance in tracking down missing main power rail.
I have an Acer that I am working on. It runs on the battery, but does not charge. I changed the power adapter and same thing battey not charging, and continues to discharge. So I opened the computer and started looking for the problem to fix.
First thing I checked is if the power form the charger is getting to the mainboard. I found that 19V is going all the way to the first MOSFET. So DC jack is fine. However I do not have power past the first MOSFET.
So checked for voltage on the gate of the first MOSFET and... -
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