This arrived today, a NO BUGS (darn it) HP-41C Tall Nut, Half Nut. It had a totally bizarre display on the screen on power up. The display was:
0.0000 ' ' ' ' '
Executing a master clear gave this display:
MEMORY L@2+
Clearing the memory clear message resulted in the first display. The calculator performed all functions correctly, with interpretation involvings some of the displays. In fact, with FIX 9 set there was almost no numeric problem on the display as the correct digits masked the apostrophes correctly.
Switching to Alpha mode displayed the apostrophes and these rode on top of any alpha character.
I tried the master clear, shorting the contacts and reversing the battery (yuck). No joy so I replaced the LCD with a good one from a donor PCA with cracked contact domes and two missing battery posts. Success! What followed was a thorough spa, and back together it went.
I thought you might appreciate a close up of the tall keys versus a normal keys fullnut HP-41C from 1982. These pictures were taken at the same angles for each example. Enjoy.
Normal keys top view, note the easily read blue labels from a vertical view:
Tall keys top view, note the hard to read blue labels from a vertical view:
Normal keys side view, note the smooth face
Tall keys side view, note the framed raised portion similar to the classics.
Normal keys front view, again the smooth face.
Tall keys front view, the framed front piece, artistic touch.
Edited: 18 Aug 2009, 11:48 a.m. after one or more responses were posted