i had black screen after trying to clone ssd from a hdd.
I suffered a power loss during process.
I tried to install the possibly cloned ssd...black screen !!
..tried to reinstall old previously good hdd ..black screen !!!!!!!!....
i went round and round in panic ....just in case i was missing something
..... then I decided to take out the extra ram Id just fitted before doing the ssd upgrade
... and hey presto the hdd booted back to life 😉 ...... thing is id ordered the exact ram that Hwinfo64 identified
HYNIX HMT35156CFR8C-PB X2 BANKS OF 4GB but they sent HYNIX HMT451*********** as a compatible upgrade
refitted the new ram...black screen.....took it out ...... all good .....
point is when you open up the top 2 decks of ram are easy to knock... just saying ....You could check that your ram is in good and its good ram !!!