http://www.ebay.co.uk/itm/REPLACEMENT-BACKLIGHT-for-AKAI-S1000-S2800-S3000XL-SAMPLER-by-RETROILLUMINATION-/321625308423?pt=UK_Musical_Instruments_Pro_Audio_Samplers_Accessories_CV&hash=item4ae25cbd07
Contact this guy “saint_baz” on eBay if you wanna go the custom screen route - he’s based in UK, super helpful, and while he may not be able to supply the screen himself, he’s definitely got the knowledge and the supplier info you need to go DIY.