Laptop parts swap completed; fault in V2315CF power distribution board

FOUND AN ERROR IN THE V2315CF POWER DISTRIBUTION BOARD

I was rewiring the Virtual 2315 Cartridge Facility (V2315CF) with the final versions of the power related equipment, doing a bench test with everything connected to sanity check the operation before it was installed on the IBM 1130. 

The power from the battery (and its permanently connected charger/maintainer) is connected to the V2315CF power supply through a ride-thru timer module. This module is powered by the battery, but its trigger is the incoming 12V from the IBM 1130. As long as the 12V is arriving from the IBM 1130, the timer keeps the connection to feed into the V2315CF power supply. 

When the 12V from the 1130 drops, the timer retains the connection of the battery to the V2315CF for about 40 seconds, which will be long enough for the V2315CF to do an emergency unload and writeback of a virtual cartridge file if it was loaded when system power failed. 

I had the timer wired in, the battery, and the V2315CF power supply. I had not yet connected the charger/maintainer when I tried the first test. With no simulated 12V from the 1130, the timer had disconnected the battery from the V2315CF power supply. When I provided 12V to the timer to make it activate, a trace quickly burned through on the Power Distribution board I was testing. 

Some checking uncovered the fact that when the relay activates, it connects the battery input directly to ground! It also connects it to the V2315CF power supply, but ground wins in this contest. That is not correct. 

I opened the KiCad design files and discovered an unintended connection of the terminal block screw 10 to ground. I had tied all the ground screws together and marked that net as ground. However, when I drew the line from screw terminal 10 to the power supply input diode, KiCad helpfully added a dot to the wire it was crossing to connect it to ground. It was only because the ground symbol was close enough to the horizontal line from screw 10 that it assumed they should connect. 

I guess I didn't notice that because all the other even numbered screws are actually ground connections - 2, 4, 6, and 8 - so this wasn't visually different. However, it does mean that the board is not usable. I did a quick fix and sent it out the JLCPCB to fab a new set. 

THE SECOND LENOVO LAPTOP ARRIVED TODAY AND I DID THE PARTS SWAP

I had ordered a "used, good as new" Lenovo Ideapad L340 17IRH gaming laptop from them through Amazon. I opened up both of them and exchanged the SSD, the Intel Wifi/Bluetooth module, and the RAM card. I changed the RAM because the replacement laptop only had 16MB installed while my original was a 32MB machine. 

The 'new' machine is working great. I tested all my node locked software, no issues. It did meet my primary goal, which was as expedient a repair as possible with minimum downtime from my more important project goals.