FDS4435BZ P-channel MOSFET

U10: Intersil ISL6255HRZ Integrated battery charger with automatic power source selector for laptops.

U2, U1 : Fairchild FDS4435BZ P-channel MOSFET (connector control on circuit)

U42: Fairchild FDS6298 N-Channel MOSFET (Vcore-Hi CPU)

U39: Fairchild FDS6676AS MOSFET N-Channel (CPU Vcore-Low)

C437: SMD ceramic capacitor, not less than 25v

The circuit of U2 and U1 is not exactly similar to what appeared in the test circuit of the ISL6255 data sheet. This is more similar to the circuit in the case of TI bq24751 except that the exhaustion and source are reversed.

Connector - > S-U2-D - > D-U1-S - > SYSTEM

Frame - > D-U42-S - > Vcore - > D-U39-S - > weight

U42-D - > C437 - > U39-S (Ground SYSTEM for U42+U39)

The frame is 19v from the connector or 11v from the battery.

I have this PC for profit. It powers any power source in the outage. A short film should be easy enough for me to get to work. Since my first workstation motherboard required more than a power outlet, I didn't recognize what to look for. I assumed that if I pulled enough coins, I would find out the problem.

The power connectors are simply short and close, so I add power from the seat to the power outlet and increase the voltage. At around 1.1v 1 ampere, the primary U2 in-line MOSFET warms up. She tried not to be short-circuited, but rather to warm herself up, so she went out. At that time, I put the control power supply from the seat to the failed circuit point by U2 and U1 warms up. It goes on and on. Each MOSFET on lines U2, U1, U39 and U42 warms up and exits. All DCA55 tests except U42 which was devastated during the evacuation. The shorts are still there and this time C437 is warming up. The C437 comes out and the shorts are gone.

At the moment, everything bodes well. U42 and U39 probably did not warm up since the current for C437 does not know them. C437 is directly among them and I expected the MOSFETs to get hot, not the top. U2 and U1 heated up because they were legitimately working and trying to provide a short circuit.

I got an FDS6298 swap for U42 and pulled a top shot from a comparable area on a terrible board and the workstation works. Another electronic device was spared by the residue receptacle.

It's a terrible summit, but finding it isn't quite the same as finding terrible electrolytes.