If it's stuck in Tilt it won't start. Clipping the diodes was probably part of bypassing them, but check the schematic and see.

So the MPU is going through all flashes but the game is not booting, meaning no displays or start up tune?

The next thing I would do is open switch 7.

Check the tilt switch under the playfield too (between the flipper mechs).

Looking at the schematics from http://www.ipdb.org/machine.cgi?id=4497 there are three pages that show cabinet assembly wiring. Unfortunately, I don't see a color code. The screen shot I've attached shows the tilt bob and the tilt roll cage. Look for those and the one Quench mentioned between the flippers under the playfield (which may or may not be the roll cage, not sure).

When you find them, try unhooking one of the wires. The switch test should then go to the next stuck switch, if there is one.

NightRiderSchemSS (resized).png

Edit: I apologize if I'm telling you stuff you already know. It's hard to judge someone's technical level from a few posts. Know that there are people here who can definitely help you fix your game. Quench is one of the best. There are many others.

The number in the square block is the color code. First number is the primary color, second number is the chaser. Key is at the bottom of the page.

crusinsam try unplugging and replugging the coin door. Likely just dirty plugs.

Shawn

I had a look at your videos, it looks like your problem might be deeper than just the tilt switch. Notice the messed up displays and playfield 6k and 8k bonus lamps stuck on.

With the machine ON and running in switch test mode, disconnect the J3 connector from the MPU board (this connector is the cabinet switch harness). Does the switch test still indicate the tilt switch is closed? If yes, then disconnect the J2 connector from the MPU board (this is the playfield switch harness). If the game still says the tilt switch is closed your problem is on the MPU board.

Can you post clear pictures of the MPU board just incase we're looking at battery corrosion issues?

Some of your book-keeping data might be corrupt so it might be an idea to go through all your book-keeping settings and clear them back to zero (to clear them press the SW33 switch top of the MPU board at each book keeping function). Of course, set the first three award and highest score to date thresholds (pressing the start button) to your desired scores.

Your original boards are in very nice shape. Luckily, someone's removed the original nicad battery from the MPU board before it could leak and cause corrosion damage.
Looks like they didn't hook up any type of replacement battery though and it's the reason your book-keeping data is probably corrupt (nothing is keeping the data valid while the machine is off). There's a few ways of dealing with this.

In the first video you're also missing some chime sounds so aren't getting the full power-up melody.
Might be an idea to go through the game test modes to check that all lamps are flashing, then that all displays count 000000 to 999999 and if all solenoids activate at their respective test numbers as listed in the manual (printed page 21).

Gotta agree with Quench. I think the MPU is booting fine.The lamps are not working as are the coils. Only one display is showing correct data. I'm guessing there is a problem somewhere in your addressing or one of the PIA chips is bad. Carefully swap the 2 bottom large chips on the MPU, U10 and U11. See if that changes things. Also check the connections on J1 and J3. After that try disconnecting the lamp board. Something is not getting selected properly.

Yes it can. The 5101 socketed RAM chip at U8 is where a replacement NVRAM would go.

http://nvram.weebly.com/

The red w/green wire is not required on your start button. The only wires required there are the blue w/white on one side of the switch and the red w/yellow on the other.

The big white switch on the door is not factory. I do not know what someone was trying to accomplish there, but the red w/white and brown w/white wires are for the coin slot switches so I imagine it has something to do with adding credits.

Should look something like this.

IMG_9994 (resized).JPG

So it appears the added door switch had the coin switches wired to it and the return was on the third tab of the credit button. (Start switch.) The idea being when you started a game it would add a credit. Not sure it was done right but could definitely be the cause of your problem.

Shawn

FYI

CDWH map1 (resized).jpg