I have 28 years of IBM field service and was the test tech on the first ATM's developed I am fully capable in assembling a printer of any type with the proper documentation.
But when you have instructions that say to plug the leads into..... look at schematic and there is NO schematic or it says look for this BLACK part and there is no picture of the part and it turns out to be red It gets a little confusing.
What I am trying to say was that no one should put a product on the market that is incomplete in instructions for assembly and expect a person to recreate the wheel.