Asus TUF Z390 Pus Gaming

[Med-Tech]

Hello,

I bought a MoBo from Ebay as working, when it arrived I set it up and guess what? That is right, it did not work! In fact it killed the CPU 😡 I have checked the pins on the socket, but I cannot identify any broken, missing or misaligned pins. Attached are a few photos of the socket. It would be great, if you could look them over to see, if there maybe is something I have missed and let me know.

Other than the socket, what other things could be killing the CPU? PSU is working fine, tested all cable values, checks okay. I decided to buy a few compatible, but cheap CPUs (pre-tested in a working MoBo). Installed another CPU and got no device connected on the monitor, reset the BIOS, that made no difference. Took out the CPU, retested in working MoBo and the CPU was fried. Only one stick of Memory and tried in all slots multiple times. Other than that SSD was connected during testing.

Thanks for reading and I would appreciate any given advice.

[DynaxSC]

Socket looks good, but looking only from top might not be enough to check it definitely.

This ASUS board should start without CPU inserted, so don't waste another CPU for testing. Just start the board w/o a CPU, and measure VCORE on the cpu vrm coils, as well as other CPU voltages, eg. VCCSA, VCCIO, ....
VCORE should be ca 1V, if you get much more than 1.4V, your CPU is at risk. Check also DRAM voltages, 0.6V and 1.2V, 2.5V, 2.5/3.3V if present and in specs. If your CPU has been killed in this board, most problably some of these voltages is much too high, or you have a short on VRM mofets to 12V ATX power, having 12V on VCORE. If so also all 6.3V electrolytic caps in the VCORE net are fried, as well as probably all MLCC caps rated 6.3V or less. Check whether any of the VRM power mosfets are not fried/shorted (might be visible, but must not be). Check also if any smd parts in the VRM area are not ripped off (some of the resistors are crucial for correct VCORE voltage setting). Check VRM controller power supply voltage present, and if controller chip not hot.
BTW resistance to GND on VCORE w/o CPU is usually 100ohm, check it too, measuring might take some time, as the caps will be charging during measuring.

[Med-Tech]

Thanks for the CPU tip. I done some voltage tests and have uploaded a pic with the values. I was not able to find any shorts or see any missing or broken parts (visual inspection) from what i tested.

[Med-Tech]

Been doing more testing. Tested the Power connectors again, no sign of a short there. Decided to look at how the MoBo reacts under different conditions (in terms of heat), with and without CPU installed. Here are the results. Maybe someone with expert knowledge can identify a problem.