The screen is blank but backlit. I can sort of distinguish some black or dead vertical lines). The phone works (I can hear the boot music).
I've already opened the case and re-seated the LCD connector but it didn't help.
Digitizer + LCD = ~$22 on ebay. Phone cost $40. Probably not worth repairing is it? Is there anything else I might be missing?
Depends on how tight your wallet is. The Y550 is a pretty basic phone… only 1.5 gigabytes of actual storage is available for apps, and that's not a lot because the bloat takes up more than half of that already.
If you replace the LCD and it does not work because its a logic board problem, then you waste your money. So it's a gamble.
You could get a newer, more up to date Huawei for 98
https://www.bigw.com.au/brands/huawei/?siteName=BIG+W&rrBran…
Not for $22 + labour. You might find out its a motherboard issue.
Try selling it 'for parts' or look for another selling 'for parts'. You can probably salvage it for $5.