Hi Ivy
I understand your reluctance to move on from your loved Tyros 2 but look at it a different way.
All the Tyros models are now very old, and as both you and I found out, nothing lasts forever. It's older technology now, and although the Tyros series were all great, you realistically only have 4 possibilities.
It May be worth getting somebody to try and fix it for you. Probably economically a complete waste of money.
Or buy a Tyros 3/4/5.
Sell it, as is for the spare parts. Sell the E473 too to realise more funds. It's a very poor substitute for a Tyros.
Buy a newer PSR-SX 700 with the touch screen.
I too bought an E473....frankly it was a bad buy, it's a toy, so I sold it. But the more advanced SX models are just amazing, awesome in fact, and fun to play too.
I wouldn't buy old technology, because to me you're throwing money away unless you know how the previous owner used it, or, you find new old stock never used.,and now, having a touch screen SX700 I wouldn't ever go back to a manual entry keyboard.
Go treat yourself.... Life's too short...
Keith