Rear windscreen defroster not working

[WhoeverYouWantMeToBe]

I have a Corsa and a few strips of the defrosting grid on the back screen aren't working. I must have scratched them when cleaning or something (never knew how sensitive they were )It's coming up to the time of year where the windscreens fog up in the cold, and also ice and frost on the horizon.... Is there any way this can be fixed myself (or by DP ) or is a whole new screen the way to go? Which I can't really affor, and I don't have windscreen cover on my insurance... I've read really bad reviews on the only product I've found that claims to help you fix it.
Any advice??

If there are breaks in the 'hotlines' and they're very small, the product I think you're referring to might be OK. Anything more that 10mm means the current will struggle to get across such a large span. Plus, more than a couple of lines means you could spend a lot of time and money on trying to fix a problem with little or no success.

A new window will come with a guarantee and may not be as expensive as you think. Secondhand glass may also be a cheaper option.

Where are you based? I might know somebody in your area.