Hey

Im trying to install new ram in my laptop, long story short, the 2nd memory slot doesn't appear to work at all. Tried new ram (identical ram including part numbers, 2133mhz as recommended, even though the 8gb kingston 2400mhz is the default ram and runs fine). When i try booting laptop with 1 ram stick, it works, regardless of which ram is used, old or new, when i try adding the second ram, black screen. The laptop powers on with and without power lead but it won't load past the black screen. I've reset battery, bought identical ram, cpu-z used before purchase to make sure i was getting compatible ram and a few nights of research (four different sets of ram tested and same issue). Clearly the 2nd ram slot appears to be defective. Bought this about two years ago and it has been treated like a member of the family  
As there are very limited options in the bios i can't tinker with voltage for each slot or even check if laptop recognises the second ram slot. Can this be fixed or replaced by acer, very disappointing to be sold something at around £750 at the time to find out i can't add any ram due to the fault. Wish i'd have researched the motherboard a bit more before purchase cause it pretty bad compared to the other parts but thats a hard lesson learned. Anyone in a similar situation or had similar issues with this make/model?
To think that a company can sell something defective for so much leaves a sour taste, thought these things are tested during construction of the laptop but evidently not