Newby here. Just starting to learn the basics. I have a Gottlieb/Premier Raven (I'm not ashamed). The A-coil which controls the ramp will sometimes fire rapidly, causing the ramp to shake violently up and down. Turning the game off and back on will sometimes stop the ramp from shaking but then the ramp will always be in the up position. Triggering the target sequences that is supposed to make the ramp drop does nothing. The ramp is stuck in the up position. I have replaced the coil/sleeve (then read that the coil itself is almost never the problem). The ramp fuse appears to be fine and I see no loose wire/ ground issues.
Are there any possible solutions that do not require a masters in electro-engineering?