Take pictures of screw placement before disassembly, as screw lengths often vary.
Be careful of low-resolution scans or incomplete PDFs floating around on random forums. You need a clean copy where you can actually read the resistor values (e.g., R124 vs. R184). Tascam Cd-401 Mkii Service Manual
You might think, “It’s just a CD player. How hard can it be?” Hard. The 401 MKII is a complex electro-mechanical beast. Guessing which screw to turn on the laser pickup or which belt goes where is a recipe for a very expensive doorstop. Take pictures of screw placement before disassembly, as