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Removing and cleaning the front panel of a 42S
11-21-2017, 12:36 AM
Post: #1
Removing and cleaning the front panel of a 42S
Hi,

I've recently acquired a 42S from ebay, and noticed that the front panel has a lot of finger
grunge from the pevious user. I'd like to remove the front panel in order to clean this and would like some advice.

Is it easy enough to remove the front panel?

Is it worth removing the panel to clean, to prevent dirt scrapings from getting into the cracks next to each button?

What should I use to clean the panel, whether I remove it or not.

I've found this info on removing the panel, and would like to ask if this is the best or preferred method.

http://www.hpmuseum.org/cgi-sys/cgiwrap/...cgi?read=5

Quote:After removing the battery cover and batteries, I use a 1/8" drill bit to cut off the tops of the four heat stakes. (I mount a sharp bit in a counter-sink tool, and rotate it slowly by hand -- one doesn't need to go too deep.) This frees the front and back case halves at the top (display) end of the calculator.

To fully separate the halves, I've then just carefully but forcibly pried the four lower heat stakes apart, working from one side to the other, with nothing other than my fingers. The keyboard is backed by a metal plate and remains relatively stiff, the PCB is free and unstressed, and the back attachment is plastic only.

At this point, you'll have the back cover and front (keyboard) separated. In the older models, the back is lined with an aluminum ground shield, presumably for the reduction of RF interference. In the models with beepers (17B, 27S, & 42S), you'll also see a piez


Thanks

Tony
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11-21-2017, 02:56 PM
Post: #2
RE: Removing and cleaning the front panel of a 42S
Hi Tony,

If by "removing the front panel" you mean separating the case halves, I don't think that would be of any help. It is possible to remove the faceplate by using the heat from a hairdryer to soften the glue beneath, then lift the faceplate from the front of the calculator. Not recommended though since any bend you might make in the metal faceplate is difficult to remove and will be noticeable after reattaching the faceplate.

To clean the "grunge" from the faceplate, I've used alcohol or a mild diluted soap cleaner. Avoid any strong solvent since it may damage the plastic or lift the lettering. Cleaning tends to involve several hours of cautious scrubbing for good results.

BTW since the deposits are generally mostly organic material, a touch of saliva works well too Smile
~Mark
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11-21-2017, 07:19 PM
Post: #3
RE: Removing and cleaning the front panel of a 42S
I've been using WD-40 to clean plastics and the exterior of electronic gadgets with good success. Just a bit on a piece of cloth, I then wipe off the excess and that's it.
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