I have a HP67 I am repairing/restoring that has some clear spots on the keyboard (not on the keys). The spots are definately on top of the keyboard lettering, so I guess they could be glue or lacquer etc. My question is, how harsh a cleaner can I use to clean the keyboard (dismantled) without risking damage to the keyboard lettering ?. I have tried soap and water, I was thinking of trying isopropanol (~70%) next. Thanks - John
i did this once by leaving carbon tet (which i was using to clean the gold dome thingers from behind) on the face of a 41 for more than a few seconds. it does clean very dirty contacts. it bleaches plastic too.
John,
From what you've stated, I believe you're going to have a tough time cleaning that gunk off. The dilemma is that if you use a strong cleaner, you risk removing the lettering underneath! The lettering on the Classic and Woodstock models is known to be delicate, so that condition compounds the problem.
I suggest that you start with the least harsh cleaners and work your way up. I use the same principle when I detail my car. Perhaps you could start with a 20% solution of your 70% ethanol. If that doesn't work, increase the concentration of ethanol a bit. Alternatively, you may want to try a cleaning solution with a bit of organics in it, such as Fantastik or 409 Glass cleaner.
Good luck,
Todd Garabedian
Glastonbury, CT USA
Thanks for the suggestions guys, I have had a pretty good result. I started with diluted isopropanol solution, which didn't do anything, then used the 70% solution neat with a soft toothbrush (your wifes is generally softer than yours :-). After cleaning though, the plastic looks kinda white, I have noticed this before when using isopropanol on a HP41 display plastic, the solution is simple, a good quality finishing (not cutting) car polish.