Fixing broken switch connections on Filco 104 PCB

[delatroy]

Hello! 
After replacing all switches on a Filco that I have, some of the keys do not make a connection. They are q, b, n, /, left, right, down, numpad-

Here is the PCB in question:



The connections look good but maybe some of the traces are broken. I don't have a multimeter to check though I just ordered one.

Does anyone know where I need to rewire these keys on the board? Is there a schematic that I could look at?

[delatroy]

So I made some progress on this by testing the continuity on the broken switches:


Results

• Numpad-: passed all
• Left: passed all
• Down: passed all
• Right: passed all
• /: passed all
• N: passed all
• B: button failed, both reds fail, both blues pass. This could be a bad switch.
• Q: passed all

Given that the local continuity is okay, can anyone advise where I should test next? Is it just a mater of following the traces upstream / downstream to check where the connection is breaking?

[delatroy]

Fixed it:
https://imgur.com/a/nKSK6Aa

Bad trace from the top right pin coming off the controller. Jumped it.
Also a pad was lifted on Q which was bridged by scraping away some of the trace to reveal the copper.