HP15C reset loose heat stakes

[Zoobala]

I have a couple of keys (SST and R/S) that rattle on my 2509A unit. I removed the back of the case and inspected the PCB and heat stakes. There is a little give if pushing on the PCB on that side of the case, and a little pressure exerted on the PCB can generate a little space between the head of the heat stake and the PCB. I'm wondering if there is any advice on how to apply pressure while re-heating the stake(s) to make the fit more tight. Also what to use to heat the stakes? Finally, the unit works just fine and I don't want to muck it up. So if I should just leave it alone, that's fine also.

[Raymond Del Tondo]

Hi,

unless you have experience with a soldering iron, I'd simply leave the keys as they are.

And while we're at it: Don't overtighten the case screws, as the one in the upper right corner (looked at it from the back side) may press against the aluminium bezel and create an ugly ding left of the LCD.

Ray

[Dave Britten]

I've had a nonzero amount of success using a hot glue gun. Put a little drop on the stake to make a new, tighter seal. If you can get the glue to fill in under the existing head, that would probably work well. I've only tried it in a situation where I had removed the heads (and PCB) entirely.

[Johnboy]

I have reworked heat stakes on many HP41 calculators, but yet to try it on a 10 series, but I can't imagine it would be that much different. Like Dave, I too use hot glue gun. A little tip I found useful, is apply the glue then squish it with your finger, but first lick your finger so you don't burn yourself !

Also, to "release" the heat stakes, I lift gently around the side with a fine screw driver or blade, like a scalpel, the plastic removed is doughnut shaped. That preserves the length of the heat stake, i.e. by doing this you're not slicing the top of off the heat stake - make sense ?

Cheers,
John