50g - Differences in production batches

[Michael Lopez]

Hi everyone,

I have 4 HP50G units out of which 3 are the "normal" black & 1 unit the Blue type. The Blue finish calculator is the last one I purchased via a seller in USA (as I recollect) & it has no serial number at all on the back. It also doesn't have the "HPK-49GPLUS(B)" which is present on one of my Black calculators.

Does anyone know why the Blue unit doesn't have a serial number?

Thanks,

Michael