|Re: HP75C Display (was zebra connector)|
Message #5 Posted by geoff quickfall on 4 Nov 2010, 12:44 p.m.,
in response to message #1 by Alberto Fenini
I have been away on a trip to Bejing and for some reason the government screeners on the wifi network at the hotel have blocked HPMuseum and my outgoing email accounts! This happens from time to time.
First, remove the glue residue from the keyboard and the faceplate backing. Some type of citrus based adhesive remover and cotton rag should work. Then wash the faceplate in warm soapy water.
Place the faceplate between to thick sheets of clear vinyl, thicker then a freezer bag. I use clear to see the results.
With the faceplate sandwiched between the vinyl, the entire package placed on a VERY FLAT AND SMOOTH SURFACE (sheet of glass) and the printing visible (obverse) take a large soup spoon and rub over the ding. Flip the face plate over and rub some more from the (reverse) side. Continue this until the ding is removed.
Now with the entire face plate reverse side up rub the whole face plate taking care not to damage the reverse angle. This will impart a slight convex shape to the faceplate with the cup highest in the centre and lowest at the corners with the obverse side facing up.
This allows the faceplate to be glued in place (contact cement) with the corners fitting perfectly. Take a look at the following HPSolve article (HP42s) which is very similar to your 75.
The second half of the restoration article explains the faceplate removal and glueing procedure. Also refer to the HP65 restoration piece, specifically how I smoothed the label out on it. There is a figure refering to label placement and the vinyl used.
Good work on the LCD panel also!
Edited: 4 Nov 2010, 12:46 p.m.