Re: HP-41CX lock-ups Message #10 Posted by Thibaut.be on 16 July 2003, 9:38 a.m., in response to message #6 by Harry
Yes, next step after fresh batteries is bad contact. You can easily check this out in trying to turn it on while pushing with one hand the edges of the calculator close to the 1st row keys (LN, LOG, ...). If behaviour changes and improves while your're pressing then basd contact has been recognised.
If you hear something inside, it might be the fixing posts that are broken.
You will have to open it, but don't worry it's very easy.
1) take off the 4 rubber feet. Put them in a smaal plastic box so that no dust come on the glue.
2) unscrew the 4 screws. Make sure you recognize the short and long screws.
3) check if the posts are cracked. If yes try to recover all plastics parts
4) the calc should split into 2 parts with a center plastic part. The battery contacts and port contacts shold easily come out.
5) with a rubber, clean all contacts.
6) take a pin and put it under the flexible contacts. There is a kind of white foam that you could strecth by 1/2 - 1 mm. Make sure you dont scratch the flexible contacts.
7) glue up all the fixing posts with dedicated plastic glue (some people in the articles of this site gave exact name of components and brand). I use 2 component plastic glue that can be found il any DIY shop. Let it take the time to solodify correctly.
8) blow up all dust/dirtiness but make sure not to scratch anything.
9) mount your flexible back, make sure they are in good contact evrywhere with the PCB and the battery contacts
10) screw your calc, using the correct screws. you could put some very light grease on the screws as you will have to "dril" your fixing posts. PLEASE DO THIS GENTLY, AS CRACKING THE FIXING POSTS IS THE MAST THING YOU WANT : at the end, each 1/4 turn put the batteries on and turn your calc on : stop screwing when it turns on correctly
|