Dumb it down for us, which connector is it?

Looks like pins 1 & 8 have been jumpered.
Pins 1 & 8 are burnt at the connecter. Too much heat. You'll want to replace the header pins on the board and the connector. Verify the wiring is correct, looks like it may have been altered.
Great Plains Electronics is typically a good source of parts.
If you need an excellent repair person ChrisHibler does excellent work.

Since it's a new Xpin board I don't think you'll need to replace the header pins. Just the connector.
https://www.greatplainselectronics.com/categories.asp?cat=215
Check your spacing.

She already has the tools needed, seems she's asking for the correct wiring setup? If I'm reading you correctly?

I can grab a pic when I get home if no one else does first.

https://pinside.com/pinball/forum/topic/big-game-club-the-safari-has-started/page/10#post-3469571

Of course cottonm4 would have taken a pic at some point

Looks like you just need to repin the connector and lose the big honkin yellow jumpers.

The following is from the Big Game Schematics: https://www.ipdb.org/files/249/Stern_1980_Big_Game_Schematics_And_Wiring_Diagrams_Hi_resolution.pdf

J1 pin 1 = RED (Ground) Pin 1 also joins to pin 2 and hopefully/ideally it is done on the rear of rectifier board, assuming the previous owner didn't know this or it wasn't done they looked at the schematics and saw J1 is joined to J2 and jumped it themselves in the connector?
Also what was done to pin pins 5 & 8.

J1 pin 2 = continuity to pin 1 (Ground)

J1 pin 3 = BLUE (Feature Lamp Supply 5.4 VDC) Also joins to pin 7

J1 pin 4 = Key (Notice a blanking plug on the underside of the connector, So connector only seats one way, separating it from other plug connections)

J1 pin 5 = WHITE (General Illumination Supply 7.3 VAC) Also joins to Pin 8

J1 pin 6 = BLUE with WHITE tracer (Solenoid Supply 43 VDC) But I see in your pic it has a BROWN with a WHITE tracer, could be an error on the schematics or Stern changed the colour wire at that time?

J1 pin 7 = BLUE (Feature Lamp Supply 5.4 VDC) As above joins to pin 3

J1 pin 8 = WHITE (General Illumination Supply 5.4 VDC) As above joins to pin 5

Don't worry that you have 9 pins on your rectifier board but only an 8 pin plug.
Later games used a 9 pin header so make sure the keying plug is in Pin 4 and pin 9 is not used in your case.

Every classic Stern will be the same. Put some LEDs in the backbox (at least) to lighten the load. And get rid of those jumpers.

I mean no offence here, but the crimping tool you have is very basic and wont imo give the 'correct' crimp required.
Crimping tools can be quite expensive.
Whilst not top of the range, will give a better crimp: https://www.greatplainselectronics.com/proddetail.asp?prod=1026-CT

To remove the pin/wire from the housing you simple push down on the locking tab as seen where the burn marks are, then pull on the wire to remove.

But if you are intent on crimping new pins into a new connector, you can use a 9 pin connector housing so the 9th pin isn't left exposed, up to you.

I suggest using Trifurcon pins as seen here: https://www.greatplainselectronics.com/proddetail.asp?prod=08-52-0113
These pins have 3 areas of contact opposed to one on the original pins.

8 Pin housing with locking ramp, ignore the locking ramp as it won't be used in your case:
https://www.greatplainselectronics.com/proddetail.asp?prod=CS156-08-LR

9 pin housing with locking ramp, ignore the locking ramp as it won't be used in your case:
https://www.greatplainselectronics.com/proddetail.asp?prod=CS156-09-LR

The burn marks are cosmetic and don't affect the connection. You may be able to leave as is?
What is suspect is where an additional wire has been added to the original wire and how it is making connection/crimped.....they may have been soldered.
But the idea that has been incorporated is to share the load of current through 2 pins instead of one, but essentially going back to one wire.
What may have been compromised is not using new pins, the original pins having got very hot causing the tension in the spring of the contact to weaken and increase resistance causing the generation of heat.

Anyway, that's my rant, didn't mean to over load you with detail, but starting out can be tricky and confusing.

Just like this.

16372831267525372895694677045540 (resized).jpg

Those yellow jumper wires add extra current capacity on the G.I connectors.
Bally used those extra pins to share/split the G.I current load to the playfield. Stern chose not to, to save a few cents on wire.

You can argue the execution all you want but they are a worthwhile redundancy measure in my opinion. Just like all those ground mods people religiously do.

Yes that crimper will do fine, but may wear the crimping head, depending on how many crimps you will be doing, which I see is able to be swapped out.
Those 2 wire gauge sizes in that one head will do all you need.
I use this: https://au.rs-online.com/web/p/crimp-tools/7106499
purely because I don't like ratchet types, but as you can see the costs of crimping tools goes quite high, each to their own and how deep your pockets are.

are all the fuses on the rectifier board intact?

can you post a pic of your repinned connector?

That's your incoming power your on off switch might be bad or wired wrong or the line filter and mov if it's got one might be bad as well. I suppose it's possible that the transformer is bad but they are very reliable. You could have a bad connection into the connector too from the line voltage.

Your last three connectors are off by one space. See the picture.

It's a 9 pin connector that you have. the original was an 8 pin.

Shift those three all one space closer to the center.

Capture1 (resized).PNG

Maybe those will help. And triple check you wired the new rectifier board correctly after verifying you have your connectors pinned correctly.

Yeah I'd be looking at the back of the rectifier

as mentioned in #20, fuse F6 is related to connector J2 pins 6 & 7.

check you connections from the transformer to connectors E1 & E2 on the rectifier board.

forget wire colours and sizes for the moment, hoping no one in the past has swapped out wires and used thin where thick should be?

Rectifier Board to Transformer:

E1 = Lug 5 AC active
E2 = Lug 1 AC neutral

E3 = Lug 2 Solenoid Active
E4 = Lug 6 Solenoid Neutral

E5 = Lug 8 Display Active
E6 = Lug 10 Display Neutral

E7 = Lug 17 General Illumination Active
E8 = Lug 18 General Illumination Neutral

E9 = Lug 13 Switched Illumination Active
E10 = Lug 14 Switched Illumination Neutral

E11 = Lug 15 Input for 5V Regulator Active
E12 = Lug 16 Input for 5V Regulator Neutral

If all is correct then you need to look at where the mains comes in, as that is what is causing the fuse F3 to go open.
From the plug that goes into your wall plate 3 wires join directly to the input side of the line filter, and the active and neutral to a varistor.
If either/both the line filter and varistor are shorted this will cause the fuse F3 to go open.
After the line filter both the active and neutral lines go the power on/off switch then to connector J2 pins 6 & 7.

looking at your wiring of J1 in #you put 43VDC on the switched illumination bus so it's a blessing in disguise that your AC fuse blew first (hopefully) or you'd have blown all your switched bulbs.