It happens quite rarely that the motherboard will boot. At first, the X1 quartz sizzled even when the power supply was unplugged and the BIOS backup battery was charged. When I slightly bent the laminate of the motherboard in the upper left corner to the center, the sizzle stopped and the board started up. So I corrected any solder in that area. I desoldered and checked the transistors adjacent to the X1 quartz. I replaced all tantalum and ceramic capacitors (except coin). I checked all the elements for a short circuit, checked any suspicious paths that I could see. I was programming the BIOS. I replaced the BIOS backup battery. I checked if there is power to the chips, to the ISA and RAM slots. The error code stops at 13 after a while it switches to 00.

The processor, as you can see in one of the photos, had several legs skewed. I bent them so that they did not touch each other and checked if they all have a connection to the pads.

I bought a quartz resonator tester. I wanted to test the X1 quartz with it to find out what value it has, but there is no reading. I also tried soldering a similar looking quartz from another motherboard from a similar period of time but it didn't help.

Is it a short circuit between the PCB layers or something else could help?