User Tools

Site Tools


hp_9100

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
Next revision
Previous revision
hp_9100 [2018/07/29 22:58]
cic ↷ Page name changed from 9100 to hp_9100
hp_9100 [2018/09/07 23:09]
cic
Line 27: Line 27:
 <​imgcaption CR| Replacement CR1 vs Failed Original(red) >​{{:​9100:​9100_repair:​baddiode.jpg?​400|}}</​imgcaption>​ <​imgcaption CR| Replacement CR1 vs Failed Original(red) >​{{:​9100:​9100_repair:​baddiode.jpg?​400|}}</​imgcaption>​
  
-Replacing these two components produced good CRT output and a largely functional machine. ​Final step at this stage was to replace the two register illumination bulbs, which are CML 7382. Note that these are 14V bulbs being driven at 15V, pretty strange for HP, which is more likely to under-drive components. I'm looking for an 18V replacent to lower the heat output and increase longevity.+Replacing these two components produced good CRT output and a largely functional machine. ​The final step at this stage was to replace the two register illumination bulbs, which are CML 7382. Note that these are 14V bulbs being driven at 15V, pretty strange for HP, which is more likely to under-drive components. I'm looking for an 18V replacent to lower the heat output and increase longevity.
  
 At this point, I was able to begin functional testing. I was able to work through the validation steps in the User Manual and Repair Manual successfully with only two problems - the "​8"​ key didn't work and the Degree/​Radian switch feels gummy and works inconsistently. Contact cleaner, gentle massage and burnishing of the key contacts with a narrow strip of bond paper solved these problems. ​ At this point, I was able to begin functional testing. I was able to work through the validation steps in the User Manual and Repair Manual successfully with only two problems - the "​8"​ key didn't work and the Degree/​Radian switch feels gummy and works inconsistently. Contact cleaner, gentle massage and burnishing of the key contacts with a narrow strip of bond paper solved these problems. ​
  
-Initial testing of the card reader ​shows problems - the card drive mechanism ​works (card is ejected) when either the RECORD or ENTER buttons are pressed, the rubber drive wheel is intact and functional, but data is neither read nor recorded. ​Cleaning ​the head seems to have solved the problem, but I'm still testing and learning my way around this machine.+Initial testing of the card reader ​showed ​problems - the card drive mechanism ​worked ​(card is ejected) when either the RECORD or ENTER buttons are pressed, the rubber drive wheel is intact and functional, but data is neither read nor recorded. ​I'm lucky to this point, since the drive wheel is not just an circular "​tire"​ - it has a flat on one side, designed to let the magnetic card slide into the reader. When the drive is actuated, the wheel turns past the flat and the rounded side of the while drives the card out of the reader, pushing it past the magnetic head as it is ejected. 
 + 
 +Later note - cleaning ​the head seems to have solved the read/​write ​problem, but I'm still testing and learning my way around this machine.
  
 ====== Images ====== ====== Images ======
hp_9100.txt · Last modified: 2018/09/07 23:09 by cic