SPI_CLK problem on MSI MPG B550 Gaming Plus

[jankor]

Hello. MSI Motherboard has a problem with SPI_CLK signal on BIOS chip. Startup procedure stops wich "CPU debug" led. I've checked SPI_CLK line with oscilloscope - there is only around 1.6V without traces of 48MHz oscillations - BIOS chip not sending data to CPU and everything stops. I've checked all voltages (I belive) and all EN signals - everything looks ok. Maybe someone more experienced has an idea what else to check...

[PCBite]

Hi
I have a similar issue, but couldn't check the clk yet. Could you resolve the issue?
Thanks

[DynaxSC]

Check the cpu and chipset clock gen's if they work. SPI clock is probably a derivate clock from cpu or pch clock. Sometimes the clockgen circuits are becoming lazy due to silicon or crystal degradation and they stop oscillating. Sometimes helps exchanging crystals, pf caps in the clock gen circuit, and finally the pch if pch silicon is degraded.

[m1ch43lzm]

BIOS is directly connected to AM4 socket according to schematics, try with known good Ryzen CPU

Schematics: https://www.badcaps.net/forum/troubl...7c56-boardview
Boardview: https://www.badcaps.net/forum/troubl...rdview-request

The B550 A-PRO and MPG B550 GAMING PLUS are 99% identical boards