HP 5335A non working ENTER key... Other eq. might use the spring loaded buttons

[Dr. Frank]

Hooray!!   

Great job done.

Have fun, it's really a nice unit, genuine HP-feeling, especially with the options installed 

Frank

[DimitriP]

BTW: What do I refresh the rusty springs with in pic 2?

Ypu could brush them and then use a rust converter chemical or...or....
Dunk them in white vinegar (might take a couple of hours or overnight).
Give them a light coat of machine oil. 
Reinsert
Use
Enjoy.

[VK5RC]

Re rust inhibition, i have had a lot of success with an Inox Lanolin oil after a light wire brushing, others have used a 'gun' oil, with success.

[Turbon]

Thanks for the tips. I will try with vinegar first.

Regards

[xrunner]

What I also decided to do, in order to make the plastic a little more "slickery", is to wet a foam applicator a little bit with Armor All, and touch it to the red plastic right next to the white push-button. If you observe the action of the metal strip, you will see that it slides a little bit against the red plastic there. I believe this makes the switch work even better.

So, the buttons work like new ...

I'm baaaaaack ...

Since the "fix" I performed almost a year ago - the sticky issue has re-appeared on many of the keys over time. Although they still switch OK, I do not like the stickiness. I am not convinced that there is nothing left to do, so I'm going to pull the unit and dis-assemble again to try to find a permanent solution. Right now I'm thinking it has to do with the dryness of the surfaces the metal strip is pushing and rubbing against. I'll give it my best shot. Stay tuned. 

[ManateeMafia]

My keypad was pretty bad. I believe I used some DeOxit on the keypad and the difference was huge. I cannot remember if it was the gold DeOxit but if it is gold plated, then that's what I used. You can try it on a single switch if you have some available.

[xrunner]

My keypad was pretty bad. I believe I used some DeOxit on the keypad and the difference was huge. I cannot remember if it was the gold DeOxit but if it is gold plated, then that's what I used. You can try it on a single switch if you have some available.

What I think now is causing the sticking is how the little piece of metal they use as a "spring" is rubbing against the plastic of the key - the part of the plastic that makes a channel for the metal spring to flex against. I'm going to Home Depot to get a type of lubricant that I have in mind that is plastic safe. I'm going to try an experiment, and if I'm right it will make a big difference in the problem.

We shall see ... 

[Lorenzo_1]

I had problems with these leaf springs falling out of place on a 3325A - some were lost.  Not the best design. They proved easy to repair using spring steel from an automotive feeler gauge as suggested by others here. Just select the closest match thickness gauge (maybe ~0.005" from memory), cut it to size using regular scissors, and make small kink at one end to match the original using pliers. Getting them in place is a little tricky for the harder to get at keys but I found that a pair of curved very fine tweezers I happened to have (see pic) and a fine screw driver were enough to do the job. I've had no trouble with them since.

[xrunner]

I had problems with these leaf springs falling out of place on a 3325A - some were lost.  Not the best design. They proved easy to repair using spring steel from an automotive feeler gauge as suggested by others here. Just select the closest match thickness gauge (maybe ~0.005" from memory), cut it to size using regular scissors, and make small kink at one end to match the original using pliers.

Yea that's a good idea. You know it's interesting, that when you remove the springs the switch still acts to spring back when pushed, because of the way the plastic switch is made. Maybe an idea is to just forget the steel springs altogether?

But, I tried an experiment and it seemed to help quite a bit. It's late now but tomorrow I'll show what I did to every single switch in the thing, something new ...

[xrunner]

I obtained some silicone grease which is plastic-safe, and applied a very small amount to an area under the steel springs where they rub against the plastic, as shown in the pic. This seems to help quite a bit. Might be something to try for some of you.

But as  I said, the key with the spring removed actually does return to the off position because it has a spring effect anyway. Hmmm ...