If your machine loads, you can use software to test the keyboard, colors, and sound.
Comprehensive RAM tests, ROM checksum verification, ULA functionality, keyboard and joystick diagnostics, Z80 CPU type detection (NMOS/CMOS), and ZX Printer support.
If the CPU fails this stage, the screen remains black—or shows garbage. The test program cannot even begin. zx spectrum test program link
: For a "soak test" using software, many enthusiasts use the RAM tester from zx.zigg.net
In the modern retro-computing scene, the "Test Program Link" has evolved into a dedicated hardware tool known as the . If your machine loads, you can use software
Ensure the ULA is generating correct border colors, screen attributes, and audio beeps.
Connect your phone's headphone jack to the Spectrum's port. The test program cannot even begin
For downloading the raw source code and binary ROMs of modern, community-driven testing suites.
For fully functional machines that exhibit intermittent stability issues, the original factory test tapes (or their digital .tap / .tzx equivalents) can be loaded normally. They walk the user through screen alignment, color fidelity, and tape head azimuth calibration.
If you can still load software, these are your go-to utilities for running thorough system checks.