Replacement chip

Dear David, Following on from last month's advice and purchase of a replacemnt chip for my fulty Duplicator, I have sad news: the replacement chip has not cured my problem. If anything it’s worse. I removed the old chip (with a proper pulling tool) and fitted the one you sent as replacement. When I refitted and booted up, the Control Panel Display then showed complete gibberish where the old one had been showing a looped or stalled ‘checking device…’ notice. I noticed the replacement chip had different numbering than the old one and wonder if this important. Do I have the correct replacement chip? The original chip is numbered SST 39VF04070-4C-NHE-0712270-L and the replacement is numbered: PMC Pn39LV040-70JCE. I’d be glad of your thoughts and advice. mic