ZX Spectrum Bits & Bobs Bytes
Do a general check and remove anything that is clearly wrong or replace anything that is clearly broken
Do a full capacitor recap. Whilst you're doing this check the board for (and repair) obvious other soldering faults such as dry joints, solder bridges and damaged tracks.
Perform pre-power checks for resistances (see Maintenance Checks page)
Replace any components that failed these tests. If TR4 or TR5 need replacing then do both at the same time as they often cause each other to fail.
Perform the Power On voltage tests (see Maintenance Checks page) (potentially remove ULA until sure OK). If removed, add ULA, test in socket.
Complete composite Mod if required.
Power on and check visual
Run diagnostic ROM, perform soak test, load and run a game.
When all OK/happy, remove ULA socket from board, solder ULA directly to board and add heatsink