Actually, there is nothing wrong with overclocking itself. Every CPU has a limit, and the nominal frequency is generally not the limit, so the purpose of overclocking is to spend the same money to get more benefits. However, because each CPU can overclock in a different range and the pressure of hardware changes after overclocking is different, it is best to try overclocking slowly. If the memory is damaged, it may be that you didn't lock the frequency of the memory when you exceeded it, which led to the memory exceeding the frequency and eventually burned out.
But I think it is possible, but it is not very big. You can listen carefully to the sound made by the chassis when you turn it on. If there is nothing wrong with the self-test, then there is nothing wrong with the hardware. Then check the software again.
Even if you repair the computer, you should look for it more. It's really unscrupulous to repair the computer now. Remember not to put any parts in the computer repair shop. If he says something is broken, don't buy it from him. Buy it yourself.