How do I disassemble HP15C?

[Egan Ford]

I have a lot of dust in my display. I read that after removing the rubber feet and black tape that all that was needed was to remove the screws. I did that and the back easily removes, but the circuit board is firmly attached to the face.

I was unwilling to apply any force without more information. However, I was able to use compressed air, but a number of stubborn bits of dust remain. This approach just moves the dust elsewhere and does not remove it. It will come back someday.

And, what are the very skinny long springs for? I did not lose them.

BTW, there were a number of broken 2mm black disks floating around, this may explain the loose keyboard. There also was a 1cm wide strip of tape at the bottom that caught and secured the disks. Coincident?

[Eric Smith]

Quote:

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I was unwilling to apply any force without more information

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That's wise. Prying it will break something.

The circuit board is attached to the front case using an array of heat-stakes. If you really want to take it apart, you can carefully drill out the tops of the heat-stakes, and it will come apart. But it also will never be as rigid again.

The early units had a separate display and circuitry module that was separate from the keyboard and removable; later units like yours do not.

I'd recommend living with the dust unless it is really bad.

[Egan Ford]

Thanks. I think I'll search for a high presure air solution.

[Randy]

A word of caution is in order - you can do permanent damage to the display window of a Voyager with something as innocent as canned air. The clear, flat lens in front of the LCD has a thin metallic like coating on each side to reduce reflections (I have no idea the exact thickness, only that it can be very fragile). Some are resistive to abuse, some weakened by 20+ years of exposure to who knows what. A direct, high pressure blast can peel the coating, leaving shreds of it hanging from the lens. [Public service announcement off]

If you have an early, two module Voyager with the wrapped in that nasty black anti-static film electronics module, it's an easy job to remove the module and clean the inside of the LCD and protective window. A lint free cloth and window cleaner are fine, beware of paper towels, they can scratch the polarizer and lens.

If you have a uni-body style Voyager (one board, chips visible/mounted behind the LCD), the simplest solution is to carefully knock the dust loose.

How? With a small strip of paper. A piece of thick, slippery coated stock works best - something like the backing paper from a sticky label. You want something that is relatively soft - as the polarizer is very soft and scratches easily. Start with a strip about a 1/4 to 3/8" wide (~6-8mm) by 2" (50mm) long and slip it into the area of the display and wiggle it around until you dislodge the stubborn bits. You might need to fashion a raised, protruding edge to contact the LCD or display window to reach the problematic side where the sticky things are. Once loose, gently blow them out of the display area with canned air.

A bit of patience and the proper tools will have it cleaned up like new. Aggressive, indiscriminate blasting can leave you with an ugly, scarred display.

Edited: 22 July 2006, 4:55 p.m.

[David Smith]

When using canned "air" keep the can vertical. Do the first blast away from the machine. The can contains a gas that is pressurized to a liquid state. If you tilt the can or some of the liquid into the nozzle tube, it can leave a whitish stain on the display window. Also the liquid produces around -40 degrees when it evaporates. It can damage or craze plastic.

As an aside, you can turn the can upside down and use it as freeze spray. A can of "air" costs around $3.00 while freeze spray (the same stuff in a can with a siphon tube) costs about three times that.