Vic 20 Rev D, low voltage across the board, black screen

[KingtutUK]

It's worth noting that 74LS series chips aren't as plentiful as they used to be, and unscrupulous dealers will sell you re-marked 74HC chips (or is it HCT?), claiming them to be LS. They'll often work for the job in hand, but you need the real thing occasionally, especially in crystal oscillator clock circuits, as they're a bit analogue.

Thanks for that info, appreciated.

[KingtutUK]

Thankyou all for the replies it was eventually found to be a bad 74ls133, I replaced that and got the computer working.