Once the program loads (you will see a cyan screen with "ZX Spectrum Diagnostic v2.3"), follow this sequence:
Keyboard Matrix Test
ULA vs. Contended Memory Test
Sound and Beeper Test
Video Output Test (The coloured bars)
Q: Can I use a test program on a ZX Spectrum +2 or +3?
A: Yes, but ensure you use a test program specifically compiled for 128K or use the “48K mode” (hold the Space key while powering on a +2A). Some programs will fail on the +2A’s ASIC chip.
Q: My test program loads but immediately crashes – why?
A: The low 16K of RAM is damaged. The Spectrum uses that for screen memory and system variables. You must replace the lower RAM chips (usually 4116 or 4416) before any software will run. zx spectrum test program link
Q: Are these test programs safe for original hardware?
A: Yes. Unlike some “burn-in” programs from the 80s, modern diagnostic suites do not over-stress the ULA or transistor driver circuits. However, do not leave a pattern test running for 72 hours straight on an un-heatsunk ULA.
Your test program has loaded. Now, what does the screen mean?
As the silicon in our vintage Spectrums degrades, the "Test Program Link" is no longer just a repair tool—it is a preservation method. Once the program loads (you will see a
For every hobbyist staring at a black screen, wondering if their cherished childhood computer is now a doorstop, the test link offers hope. It isolates the fault. It transforms a vague problem ("it doesn't work") into a solvable puzzle ("bit 4 of the upper memory is stuck high").
In a world of emulators and FPGA clones, the original hardware is becoming a rarity. The test program link ensures that the heart of the 8-bit era keeps beating, one diagnostic loop at a time.
Before we get to the download link, let's understand the difference between a game and a diagnostic. A game like Manic Miner will crash immediately if your RAM is faulty. A test program is designed to be resilient. It writes specific patterns (like $FF, $00, $55, $AA) to every memory location, reads them back, and reports exactly which chip is failing. Keyboard Matrix Test
Without a test ROM or tape image, you are flying blind. You might replace a working LM1889 video chip when the real problem is a single bad 4116 DRAM.
This is the gold standard for Spectrum diagnostics. It is often what people mean when they ask for a "test program."