Just from memory and hoping it might help someone---- An appalling noise when least expected. Out of the blue comes a br.a.a.a..a.ap like the thing was losing teeth from a cog somewhere.

About 15 years ago. This was first heard on a nearly new Epson inkjet. I phoned and an Epson man called, wiped the shiny rail (the track of the print head) and smeared a trace of thin oil on the same rail. Job done!

It seems that some go dry and the print head will not slide freely as it should. A stepper motor does its best but stalls and makes this horrifying noise.

Yesterday I wanted to scan a document with an Epson Perfection. The change from quiet order to absolute panic when the same destructive barp shook me rigid.

Fortunately I remembered long ago and the cause/cure were the same. I used a narrow strip of cloth damped with a silicone/ptfe lubricant, everything is back to normal.

What made this different was that the rail is inside the scanner which had to be opened first. In short, remove two small self-tap screws at ends of the hinge on the base of the unit. This will allow thin screwdrivers to prize it open from this side until plastic lugs let go and the unit is open. None broke. It is a risk but with patience and no small bits to fall out, what have you to lose.