macbook a1811 backlight problem

Hi there,

I have an early 2008 macbook with a problem I at first thought was due to the screen inverter cable however the backlight goes off at random intervals and isn't effected with positioning of the lid like others I have seen having this issue. I've opened the mac up and the screen inverter cable seems to be fine? I don't think this is a software issue as I have done a number of clean installs, I've reset the pram etc and the issue still occurs. Has anybody got any ideas? I was quoted £70 fix at my local computer repair shop, worth it? Seeing as it is quite an old mac which I bought off ebay for £50, functionality is still great though with an SSD installed. Any advice would be greatly appreciated.