Go to every switch in those 2 rows and see if you can find a broken wire.

Can you snap a picture of all the boards in the backbox with the power turned on?
Also a picture of the MPU below the battery pack as well as the wring connected to the bottom of the MPU.

Pictures will help.
Knowing the wiring is all connected properly at the bottom of the MPU and that we can see all the LEDs on the driver board will be a good indication that all voltages are present on the driver board. Without 12V digital voltage rail getting to the MPU, your current issue of no switches working would be one suspected item.

It seems you have all your voltages.

I would swap the top let ribbon cable with another WPC game.

The bottom right two switch matrix input connectors at the bottom right on the MPU looks like someone did not do a good job of replacing the two connectors. I would replace them with molex crimp pins. I think this is a possible source of intermittent switch issues. Doesn't take much for the wires to move and no longer make contact.

Also reseat both of the female connectors within that Z-connector between the MPU and the driver board.

What was wrong with the game and what did you do previous to the row 7 and 8 switches stopped working?

This only seems to test out the MPU board. He already put the DM MPU into JD and it works fine.
Look at his wiring at J207 and J209. Your thoughts on them?

Not very well. Wires way too long and do not seem to be seated well in each pin.

OP, What was originally wrong with the game and what repair did you do previous to the row 7 and 8 switches stopped working?

Did you use one of these IDC punch tools or a screwdriver?
http://www.marcospecialties.com/pinball-parts/77-IDC

A screwdriver will not get the best connection that you would need.
It is best not to cut the wire. In fact, you only had needed just to only trim a small piece of wire off and punch it in right to the edge of the plastic housing. Going as far as you did is wasting wire. You don't want to loose the length of the wire every time you need to do a wire repair. Eventually you would have to add wire (colors are hard to find in short pieces) or your wire will be forever stressed from being pulled tight.

We need to see a better close up of the bottom half of the MPU board including the male pins at the bottom connectors, so if you can unplug those J207, J209, and the other 2 that would be great. Since you said there was corrosion on the J207 and J209 female connectors, very likely you have alkaline damage to U18, U19 and the resistors below the battery pack that need to be taken care of. Otherwise, you will continue to have random failures.

And a picture of the J207 and J209 wiring just as terryb asked for as well.

I do understand what you're saying, but terryb and I are agreeing that you still have the potential problem on the connectors you replaced. Have you used an IDC tool before? It is a tough tool to master. He had commented on why the conductivity can pass and still nto allow the current to flow. We still are waiting on better pictures of these connectors.

Personally, when an IDC connector needs to be changed, I replace them with the .100" molex crimp pins/connectors. I suck at using the IDC tool and end up hurting my palm just trying to punch in a couple of wires.

Try moving the J208 to J209 and then J207 to J206. Any change?

Is this the original MPU you show in the last pictures?
If so, looks like someone had replace the J206 and J207 connectors since someone had sanded down the traces between these 2 connectors. I would be worried there is a damaged trace between then. So J206 pin 1 should ohm out to J207 pin 1, etc...

Also, the male pin on the board at J212 pin 3 (pin counting from the right) looks like it has corrosion in the last picture.

Did you clean any corrosion off the female or male pins of J205 or J212?

Yeah, I would be very surprised if half the switches were working.

The IDC tool takes a lot of talent to use. The tool, must be used properly for the IDC connector to cut the insulation of the wire and then make very good contact to the wire that is exposed from being punched in to work correctly.
I suck at using the IDC tool, which is why I don't use it.

No. I am not asking to switch out the MPU. I just want to know if this is the original board from this game?
Just taking notes that this one had J206, J207, and J212 replaced and wondering if there was some alkaline damage that was repaired on the MPU.

J206 and J207 are the same connections. J208 and J209 are the same connections.
That is why I was asking if you could move the female connectors to J206 and J208 to see if there was any difference in the test result

I'm not expecting a difference since you need to rework the female wired connectors, but since I saw those traces sanded, I was worried about a bad trace connection. Hope not since you said the MPU was just repaired. So I gather this is the original MPU that was in the game.

Just move the female connectors from J207 to J206 and then J209 to J208.
Any difference when you test out all the switches that you had issues with ?

The opto board under the playfield? From what game?

Just move the 2 connectors on the MPU right now, do nothing else.

If moving these J207 and J209 connectors up does nothing, yeah, those IDC connectors for sure need to be replaced as the likely cause. Mschonbrun and I both agree that the crimp molex pins are the way to go.

Maybe/maybe not. Though the board has already came back from being repaired.