Technics deck producing loud hum

[Tsundoku]

My deck is currently producing a loud hum when plugged into the phono lead of my amp, an old NAD 3020. It's a Technics 1200. Now, I am almost certain that it wasn't doing this a week or two ago, but I unplugged it to take it to a party. I'm not 100% hee but I'd think I would have noticed this before? Anyone have any ideas what I can do to sort it out? There's no earth cable as the guy who replaced my cables said it didn't need it and as I said, I've never noticed a problem before.

Anyone got any insight?

[reza]

1200's are metal chassis so yes you need an earth lead or they will hum

[antwhiplash2]

What Reza said, when this has happened to me over the last 25 years it's always been the earth cable coming loose or me forgetting to re-attach it.