Question Finished cleaning my pc and won’t turn off

[Somto]

I cleaned my cpu and applied thermal paste and now my pc turns off and on then it turns on then some noise like electrical makes noise then after 3 seconds turn off then the same thing happens when I turn it on again repeatedly what do I do my components are completely fine but I noticed something white on the psu which isn’t suppose to be there/ never seen before is that the cause

 

[Lutfij]

Welcome to the forums, newcomer!

When posting a thread of troubleshooting nature, it's customary to include your full system's specs. Please list the specs to your build like so:
CPU:
CPU cooler:
Motherboard:
Ram:
SSD/HDD:
GPU:
PSU:
Chassis:
OS:
Monitor:

Might want to inspect the CPU socket for any bent or broken pins if you took the CPU out for cleaning. As for your PSU, include the age of the unit apart from it's make and model. Might also want to check and recheck all connections from the {SU to all of your components, to see if they're secure!

I noticed something white on the psu which isn’t suppose to be there/ never seen before
We're flying blind here, how do you expect us to understand what you're seeing without context? You should include an image of what you're seeing.

 

[Somto]

CPU: Intel Core I3-10105F
Cpu cooler : Stock cooler ( came with cpu)
Motherboard : H510M-A Pro
Ram: ADATA XPG spectrix D60 16gb ram DDR4
SSD : WDD BLUE 500GB x2
PSU: Seasonic 550W
GPU: Msi Gaming X 1660 Ti
OS: Windows
I had previously bent pin (1) but didn’t affect the performance or the use of the CPU so I highly doubt it. But some thermal paste touched a pin but I removed it after the Pc booted normally then I heard the electrical noise which am still hearing up till now.