Computer wont boot O_O

hello. my sister in law has a toshiba notebook and it powers up fine, however there is no movement from the fan and the display does not work? if i connect to external monitor there is no signal either. the HDD light comes on but i dont feel any vibration or sound i can not get any menus...

My laptop basicly just crashed and then wouldnt boot correctly anymore. when i turn it on it says that it failed to start. When i use safe mode it loads all the files but then restarts the computer and says it failed to start. when i load startup repair, it just shows the blue background screen and...

New computer built less than 1 week. Started having a strange issue a few minutes ago. If my comp is off for like 10min or more and i turn it on. It wont even POST. I have to try booting it up multiple times (Basically warm it up by letting it sit there on a black screen for a min or 2 ) ...

hi guys i have a problem that occured from nowhere , im on my old computer now i was on my other computer less than 1 hour ago so windows kept lagging and not responding. done all my cleaners and still the same i done a scan disk check on the next boot up but it never got to that stage it...

Ok, my aunt has a old emachines W619 or something like that. I cleaned the dust and decided to give her an old psu, working and tested, p4, compatible and working, and a geforce 7300LE, just to give her a boost. It refuses to boot now. Fans run, HDD makes its boot beep, no ram beeps or gx card...