Monitor flicker in older arcade machines is a common issue, often caused by aging components or unstable power supply. Here are the most effective solutions:

1. Check and Replace Capacitors – Worn-out capacitors in the CRT monitor can cause flickering. Replacing them often resolves the issue.

2. Stabilize Voltage Supply – Use a voltage stabilizer to ensure consistent power delivery, preventing fluctuations that lead to flicker.

3. Adjust Refresh Rate – If the monitor supports it, tweaking the refresh rate can reduce flickering.

4. Inspect and Resolder Connections – Loose or corroded solder joints can disrupt signal transmission. Resoldering may fix the problem.

5. Replace the Flyback Transformer – A failing flyback transformer can cause screen instability; replacing it may restore smooth operation.

Regular maintenance and timely repairs can extend the lifespan of your arcade machine's CRT monitor.