http://www.pinwiki.com/wiki/index.php?title=Bally/Stern

I would try reseating connectors before moving on to more in depth troubleshooting.

What happens with the lighting in test mode? Do they ALL flash?

In the restoration process were the original Bally connectors replaced?

I would try turning power off to the pin and reseating the connectors on the MPU.

Along with the previous suggestion, make sure everything is properly grounded. Power outlet, grounding braid is connected to backbox, circuit board screws firmly connected to backbox (are those new screws?) etc..

My first question is... is that a replacement lithium battery on the MPU board, if so How old is it? I would buy the concept that the person restoring it wanted to keep it original, However the caps on power board look ancient as well.

If those caps on the power board are original then they need to be replaced.
As well as getting that Lithium battery of the MPU board and installing an off the board option (battery pack on the inside of the back box with wires running to the board)

On board original batteries are responsible for damaging 95% of the bally/stern MPU boards of this vintage.

On the Lamp Driver board, you remove the input connectors, on the left side, but allow the right side outputs to remain connected do all of the controlled lamps remain on?

Yes, there is a replacement for the Aux lamp driver board, but it is better to resolve your always on controlled lamp problem first.

those connectors don't look like they have the rejection keys in them. careful they are plugged in corretly !!!!

Also it's hard to tell if the lamp driver board has a screw fastening / grounding it.(perhaps one in upper right)

The connectors on the lamp driver board look correctly oriented.

BTW, you mention all lamps are stuck on, but I count a dozen that are off in your picture.

+1

Nice looking game. KISS was my 1st machine as well. Good luck !!

Initial thoughts since the controlled lamps are not stuck on with the inputs to the lamp driver board removed are that the lamp driver board is likely OK.

Are the controlled lamps LEDs by any chance?

Can you show a picture of the connectors on the transformer rectifier board.

With all connectors in place, go into test mode for the controlled lamps to determine if they will cycle on and off.

That is the updated power rectifier board, have you tested voltage on it?

Since you mentioned a loud hum when you turned yours on...its probably a billion to 0 shot, but make sure all of your
connectors to the display panels are seated properly and check the Sustain Adj on the sound assembly (if you have the
manual, its on page 30, labeled RT 2. Don't ask me why, but just for the heck of it, I turned mine a little clockwise,
just to see what it did. I flipped the machine on and got the loudest hum, with the lights on.

I didn't try and play it though cause I turned the machine off instantly.

I turned that RT 2 back a little counter clockwise, and my machine was back to normal.

Like I said, probably won't help, but who knows?

Doug

Looking at the logic, I think you might have an open circuit in one of the connectors at the MPU board or Lamp driver board on what's known as the "Lamp Strobe #1" signal.

If you wiggle the J1 connector on the MPU board or J4 connector on the Lamp Driver board, does anything happen to the lit lamps?

If you have a multimeter, try checking continuity between the following:
MPU board Connector J1 pin 11 to the Lamp Driver Board Connector J4 pin 13

By the way have you tried swapping/replacing any of the lamps that are not coming on to see if those lamps are simply blown or if there's some other issue?

I've had some nagging problems with my Kiss before but was able to remedy all of them. Today it is 100%.

If your lamps are on but do not strobe during test mode, the first thing you need to do is to replace all the contacts in the MPU connectors. In addition, you need to replace all the rest of the connectors too.

Most-likely it is MPU connector J1 as mentioned earlier. But don't take the easy way out and attempt to reseat them and then give up or just rebuild the one that is currently giving you problems or you will be revisiting another connector-related issue in the future. Reseating usually doesn't work if the connector is shot. If it does work it's just a temporary rig that won't last.

Even though the person you bought this machine from claims it was "restored", from the pictures it looks like he only replaced the bare minimum of stuff he needed to get it up and running. The one thing he did that does look good was to replace the rectifier board with a nice aftermarket one. Originally this was the weak link with Kiss.

Here's the not-so-secret "secret" to getting old Ballys like this running reliable and not have to mess around with it again.

Replace ALL the connectors with brand-new inserts. After 40+ years they are always shot. Marginal at best.

Until you bite the bullet and replace all the connectors you will be pizzing in the wind trying to fix this thing. Don't waste your time buying anything else until you rebuild the connectors.

Here's a place where you can buy the stuff to rebuild all your connectors including the crimper tool:

http://www.bigdaddy-enterprises.com/

It takes a little practice to get good at re-terminating the connectors but after doing a few you'll get the hang of it.

It's possible that the original MPU board was rotten from battery corrosion.
It can creep up into the connector plugs!
I had an Eight Ball that had horrible female connector pins. Replaced them and everything worked fine.
Get a light and magnifying glass and look closely at the pins. Mine were green and furry!!!
Check the bottom left MPU plug first.

Changing bulbs isn't going to fix it. That's the least of your problems.

Think you need to heed the advise of Gatecrasher and pick up some connectors, corresponding pins and a decent crimper and go to town. If you have even marginal mechanical / electrical skills, should not take you but a few hours to perform the work.
Suggest you reflow the boards at the same time if it appears they have not been done in the past.

While your doing board work (if you are decent at de-soldering and soldering) You should consider replacing the caps, they appear to be original vintage and do not get better with age. Also cut out the back up battery and install a NVRAM.

It sucks that you have to go through this work for a pin you just acquired that was "restored" but when you're done it should be about bulletproof, and you will have a great sense of accomplishment when you fire up the machine!

I had some lighting and display problems recently on my Hardbody, and as soon as I replaced the connectors, problem solved! Other problems existed, but my lighting and display issues were gone.

Suggest this thread for more tips/ tricks and valuable suggestions:
https://pinside.com/pinball/forum/topic/vids-guide-quick-bally-driver-board-repair-bulletproofing

I don't know everything but I've been in your exact shoes on this particular pin and many others from the era.

Kiss is unique in several ways. I had a baffling problem that for the life of me couldn't figure out. It turned out to be the auxiliary lamp driver board which controls the "k-I-S-S" on the back box. It would play great for a while and then reek havoc with the entire machine after it warmed up a while. But fixing all the connectors was the first step to solving the problem. As long as there is the possibility that some aren't making contact (or are marginal) you really can't get to the bottom of what's going on... and these machines always need new inserts. You can probably get away without doing the displays if they all work but the rest need replaced. Your rectifier board has already been switched to the newer style so it should be OK.

You'll need the crimper from Big Daddy and a bunch of .100 & .156 connector inserts. You will also need a small screwdriver to remove the old inserts and a wire stripper to prepare the wires for the new inserts to be crimped. If you did the Gorgar you shouldn't have too much of a problem. It's just a little tedious but well-worth the effort.

I got a ratcheting crimper as described in this thread for "trifurcon" connectors .... amazon has a great price too IMO https://pinside.com/pinball/forum/topic/ratchet-crimping-tool-25#post-593034

big daddy has the header set on ebay without a minimum order (aka $22,000 shipping ) ebay.com link: MPU Connector Repair Kit for Bally Stern pinball machines

check the knocker coil to see if it's shorted , the wire look cut

What's the result from this?

I wonder if the sound board or speaker wires are picking up some induction from the displays signal. The hum being related to the score displayed is very curious to me.

All the boards are grounded through screws going to the brackets going to the metal on this game right? As far as the hum goes, are all mounting screws in on the sound board? I would think that could possibly cause a hum