comparing early flex circuit vs late rigid circuit series30 calculators



#4

Hello, I am new at this HP calculator world. Here is my first question: can anyone tell me how to tell which version of the HP-38C series I have without taking off the back cover and cking? i.e is it the early (flex circuit) or late (rigid circuit) series 30 calculator that I have?

Perhaps you can you tell by the serial number if it is an early version or not?

Thanks in advance for any info!


#5

Hello,

The earlier flex PCB 30 series machines had 2 distinct caracteristics:

1. They were rather heavy, as they had a steel plate inside to back up the flexible circuit boards.

2. The key detents were VERY firm with long travel (they used plastic snap domes).

One more thing

Because the flex circuit board machines were solderless, they were prone to having display segments blank out occasionally (a little twist on the housing usually brings them back).

Hope this helps.

Best regards, Hal

#6

Hello,

If weight=220 g or 7,76 oz => early version with pressed components.

If weight <= 220g => latest version with soldered components.

Best regards

Etienne


Possibly Related Threads...
Thread Author Replies Views Last Post
  Layout of arithmetic keys on early calculators Walter B 10 1,169 11-20-2013, 11:13 AM
Last Post: Jake Schwartz
  HP-65 short circuit Ignacio Sánchez 2 559 10-22-2013, 08:27 AM
Last Post: Ignacio Sánchez Reig
  comparing numbers on the WP 34S Kiyoshi Akima 7 1,025 10-19-2013, 09:28 AM
Last Post: walter b
  HP50G early days vs Prime early days? Mike Powell 7 851 10-09-2013, 11:17 AM
Last Post: Eric Rechlin
  Updated HP-41 Flex-PCB replacement guide. Diego Diaz 2 514 03-12-2013, 12:36 PM
Last Post: Diego Diaz
  May be a little early ... Walter B 5 675 12-09-2012, 05:04 PM
Last Post: Paul Dale
  Non HP very early LCD Calc? Ian Phillips 6 879 10-06-2012, 01:57 PM
Last Post: Frank Boehm (Germany)
  EMU41: A Little Late to The Party, but Loving It! Les Wright 3 509 05-09-2012, 03:28 PM
Last Post: Christoph Klug
  A Very Early HP Calculator Connection Les Bell 2 461 01-18-2012, 05:15 PM
Last Post: John Robinson
  Circuit for HP3421A Data aquisition Barrie Carruthers 4 576 01-06-2012, 07:14 AM
Last Post: RamLab

Forum Jump: