The original paper manual is a collector's item, but digital copies are available through several channels:
The fluorescent display may dim or stop working. The manual details the voltage checks needed to determine if the display tube or its driver board has failed. Finding and Using the Service Manual Tascam Cd-401 Mkii Service Manual
She slid the service manual across the metal desk. The spiral binding was loose, pages coffee-stained and annotated in three different handwritings. Her father’s was the oldest—crisp, green ink. Then a tech named Leo from the 90s—blue, blocky capitals. And finally, hers: red pencil, sharp and nervous. The original paper manual is a collector's item,