HP-41CV Fullnut disassembly

[Sylvain Cote]

Hello Godwin,

I have replaced several HP-41 LCDs and I found it quite easy to do.

I unsolder the pins on the main PCB and keep the pins on LCD PCB soldered.

• use a wick to remove most of the solder from all the pins
• then unsolder pin by pin, if you are right handed, start with the rightmost pin and the reverse if you are left handed
• for each pin being unsoldered:
  • use a small fiber or wood pen to put a little pressure between the main PCB and the pin
    warning: be gentle with the pressure, if you put too much pressure you risk removing the pad from the main PCB
  • then unsolder the pin
  • validate that the pin is completely free from the motherboard before going to another pin
    
• once all pins are free from the main PCB you will see that you can remove the LCD unit quite easily
  

Soldering the LCD unit back is also easy,

• clean up all the pad from the main PCB
• insert the LCD unit into its place
• push all pins, nearest to the main PCB as possible
• apply flux then solder the pins
• clean up excess flux
  

Sylvain