Troubleshooting a Dead Target Switch on a Gottlieb System 80 with the Lisy80
A target switch that stops registering hits is one of the most common faults on Gottlieb System 80, 80A, and 80B pinball machines. The good news: with a Lisy80 board and its built-in web diagnostics, tracking down the fault takes just a few minutes. The video below walks through the process on a real machine.
Why Does a Target Switch Stop Working on a Gottlieb System 80?
In the vast majority of cases, the problem comes down to one of these:
- Dirty or misaligned switch contacts — the leaf contacts no longer touch properly when the ball hits the target.
- Bad diode on the target — every switch in the matrix has a diode; if it's open or shorted, the target either stops registering or triggers a different one instead.
- Broken wire or loose connection — a fatigued solder joint, a loose spade connector, or damaged wiring harness.
- Fault in the switch matrix — an entire row or column can drop out if one shared component fails.
Diagnosing the Target with the Lisy80
The Lisy80 has a built-in web server: from a phone or computer, you get access to a real-time switch test tool. Trigger the target by hand and watch whether it's detected on screen:
- The target doesn't show up at all: the fault is upstream (switch, diode, wiring).
- A different target lights up instead: this is typically a shorted diode.
- An entire row or column stays dark: look for the fault common to that group.
Fixing the Target
Once you've located the problem area: clean and realign the switch contacts, check the diode (it should conduct in one direction only), redo any suspect solder joints, and verify continuity from the wire to the connector. Retest with the Lisy80 — the target should register instantly.
👉 Shop the Lisy80 diagnostic board or browse all our Gottlieb System 80 replacement boards.
Still stuck on a stubborn target? Describe the symptoms in a comment under the video — we're happy to help.
