When started, my computer ran normally, but it appeared dead after about 25 mins, i.e. no response from mouse/keyboard, the moniter remained the last image.
I have to manually shut down the computer. Interestly, if I started the computer up right after, it won't stay long (within minutes it appeared dead again). It could run 25 mins again when I let it stay several hours or more.
What component (or components) might be wrong?
Thanks in advance