Check for dead pixels on LCDs or "screen burn" on older analog CRT displays. Top Used Models for Hobbyists (2026) Based on current market availability and community favor:
Deeper memory allows you to capture longer time windows while maintaining a high sample rate, which is crucial for finding intermittent glitches. buy used oscilloscope
If buying locally, perform these checks to verify functionality: Check for dead pixels on LCDs or "screen
Test all knobs and buttons. Rotary encoders (the knobs on DSOs) are common failure points; ensure they don't skip or lag. Rotary encoders (the knobs on DSOs) are common
Look for a rate at least 2.5 to 10 times your bandwidth for accurate waveform representation.
Buying a used oscilloscope can save you hundreds of dollars, but it requires careful testing to ensure you aren't inheriting someone else's "blown front end" or calibration nightmare.
Connect a probe to every channel and attach it to the built-in probe compensation output (usually a small metal tab on the front). You should see a clean, steady square wave.