Repaired the Carry/Overflow lamp PCB and tested its operation with the LED replacement 'bulbs'

ANOTHER LOOSE SOLDER JOINT FOUND AND CORRECTED

The Lamp Test connection for one of the SCRs was also unsoldered. It is now properly affixed. Using the bench power supplies and switches, I was able to verify that the bulbs light with the logic signals as well as under Lamp Test.

WORKING ON IMPROVING LOOSE CONNECTION OF NYLON HOLDER TO PINS

The pins don't fit very securely into the bronze cylinders in the nylon holders, thus the bulbs can easily work themselves off the ends of the SCR pin, such as during movement of the machine from one location to another. 

I am going to work on ways to improve the grip of these, before I install too many more lamps of either incandescent or the new LED type. 

NEED TO RESOLDER THE PCB TO THE WIRING OF THE PANEL

The PCB with the Carry and Overflow lamps was unsoldered as it has direct wiring of Ground, 7.25VAC and Lamp Test signals. Now that it is fixed, I have to reattach a pair of wires to each of the three solder terminals to reactivate this set of lights. The logic signals plug onto a pin on the rear of the SCR, thus no soldering needed for those connections.

WORKING ON CONVERTING THE STORAGE BUFFER PCB TO USE THE LED BULBS

I unsoldered the PCB that holds the 16 lamps for the IBM 1130 B register, also called Storage Buffer Register (SBR) on the front panel or Memory Buffer Register. I will convert nylon housings to hold LEDs with the 470 ohm resistor, then install these on the end of the 16 SCRs.

Once they are securely in place, the board can be reinserted into the 1130 display panel and the Ground, AC and Lamp Test wires soldered onto the PCB terminals. If I am satisfied with the appearance of these,