If you cut some tinfoil or similar material about an inch wide and wrap it around the base of the mech it will effectively shim the bottom of the targets to playfield level. I did that on both of my bally's after the playfield protector was causing stuck balls.

I had a quick question: On my Lost World I have a remote battery pack but no batteries installed while im repairing the boards. I loaded some credits into it to play test and when I power cycle the credits remain on the machine. As the game is new to me and the seller knew nothing about it is it normal for the credits to stay in the memory or is there an nvram installed?

Thanks all for the response. Im not seeing any nvram or cap so I think this is just like what a few of you are saying and that there is some residual memory left on the chip for a bit. The mpu will be out of the machine for another 3-4 days so I'll see what happens.

I'm getting alot of feedback from my speaker when the displays switch back and forth in attract mode and a constant buzzing also. It got much louder after I had replaced C23 & C26 on my SDB. I tried adjusting both pots on the sound board to no effect. Anyone have any idea on where to get started?

Removed the left side screw on the soundboard and its quiet as a mouse. Thanks for the help!

Does the game start when you manually add a credit? If yes there's an additional dip switch (#30?) In the settings that needs to be turned off for free play to work if I remember correctly.

There's a tilt switch on the bottom of the playfield that may be set a little to conservatively. Try opening it up and see if your tilts go away, vibration from the coils firing may be causing the issue. Most switches will have the caps on them that have long failed and cause funny behavior which is why they are clipped or removed. They are pretty cheap, I would replace those and the spoons on the pops at the same time. The game will work just fine with the caps removed/clipped though.

0.047 for the caps https://www.greatplainselectronics.com/proddetail.asp?prod=CCD-0.047uF-50V

Anyone have a 2518-54 rectifier board they'd like to sell or a link for a good price on a new one?

Agreed that -18 board Andrew makes is awesome and a breeze to put together. I'd be in for a pair 54's if they do get made.

You can use some washers and folded tinfoil to shim your mech as much as you need. Buy a pack of #8 washers from your local hardware store and lay one next to your targets when their in the down position to see how much of a gap remains. If the washers are not tall enough to bridge the height of the target then add layers of folded foil until it matches what you need. If the washers are to tall use lengths of folded foil to match. The mech will have 4 screws holding it to the playfield. Place the washers/foil in between the mech and the playfield at the mounting points to properly have it lay flush.

The S33 switch on my mpu doesn't work and I want to change some sound settings on my medusa. According to the schematic there are only 2 points for the switch on the mpu but looking at back side of the board there are 4. Does anyone know what 2(?) points I would bridge to bypass the switch?

Screenshot_20190404-003617 (resized).png

Check w barakandl but the weebly mpu's do have an extra socket to run external roms