33e/c corrosion



#2

I recently had to repair my 33c. The display was intermittent and usually showed a low battery display with fresh batts. Turned out to be severe corrosion on the backside of the battery terminal PCB, the charging contacts (foil was peeling, blue fuzzies everywhere), and all inside the nasty little brown film with embedded conductors (hate those things!). I rewired the batt contacts to the small PCB held in the black plastic frame with thin 30# wire, soldered in place. All is well now.

From reading the posts here (not an easy thing as the search function is cumbersome), it appears the 33 is plagued with corrosion problems. Anyone know if there is a reason for it? All I can say is that my 33C was a "casual use" machine kept in a desk drawer. All my older HPs (woodstocks,classics,topcats,etc.) are kept in a sealed cabinet sans batts with dessicant bricks. And no signs of corrosion on any of them.

-JG


#3

Hi John, glad you got the corrosion problem fixed-up and the unit is working.

My best thoughts on spice calculators are here:

http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/articles.cgi?read=361

It's not an exact match, but does discuss ways that the machines can be permanently degraded, and tips to try to avoid fatal problems...


Possibly Related Threads...
Thread Author Replies Views Last Post
  HP 35S: Resistors in Series or Parallel (Portred from HP-33E) Eddie W. Shore 2 853 10-14-2013, 05:29 AM
Last Post: R. Pienne
  Corrosion ... best way to remove? Gene Wright 6 1,109 10-19-2011, 04:23 PM
Last Post: Ethan Conner
  Heat staked keyboards with sticky, bouncy or corrosion present keyboard PCAs Geoff Quickfall 12 2,022 08-15-2009, 07:55 PM
Last Post: Geoff Quickfall
  HP 33e repair Lincoln R. 2 698 07-29-2009, 09:55 PM
Last Post: Lincoln R.
  28C corrosion Vincze 8 1,515 08-10-2007, 06:35 PM
Last Post: allen
  HP 33E Battery Contact Polarity? Danny Eskenazi 8 1,417 05-11-2007, 10:31 AM
Last Post: Danny Eskenazi
  leakage/corrosion from lithium batteries? megarat 0 432 10-31-2006, 11:19 AM
Last Post: megarat
  How to halt green corrosion on HP45 copper battery contacts in battery bay? JaSon 1 607 07-01-2006, 07:27 AM
Last Post: David Smith
  HP 33E batteries Gary Smith 1 543 06-10-2006, 09:45 PM
Last Post: Karl Schneider
  HEX-DEC converter for 33E/33C Glenn Hayhurst 9 1,537 05-10-2006, 01:16 PM
Last Post: Glenn Hayhurst

Forum Jump: