Tascam 644, group not working

[hscheer]

Hi,
One of the groups (group 4) on my midistudio 644 is not working. At first i considered the possibility of a loose wire, but I couldn't see any upon inspection. All the other groups work fine. Has anybody else run into this problem, and if so how did you solve it?

 

[shredd]

Functional problems that exceed my technical diagnostic/repair skills are entrusted with an authorized service tech. Solves it every time.

 

[Jack Saturn]

It could be any number of things, like a faulty component or small crack in the path of that group. Do you have access to the schematics in the service manual?

 

[hscheer]

Thank you for the reply. I do have the service manual, but some pcbs are almost impossible to inspect due to the way things are soldered and mounted. Here is a link to the manual:

644 service manual

 

[Jack Saturn]

The 644 is definitely a tricky one to disassemble, but oftentimes with these more complex machines, the only way to probe the circuit is to unscrew some of the PCBs and work with them loosely. Your goal should be to focus on what *is* routing correctly, to help you narrow down where the short might be.

If you need someone to take a look at it and you're in the USA, I operate a business focusing exclusively on refurbishing multitrack cassette recorders and have repaired a good number of Tascam 644 units. Feel free to get in touch! https://recdel.com/

 

[hscheer]

I would love to, unfortunately I live in the EU. Do you know of any technician in the EU who is good with 4-track cassettes?

 

[Jack Saturn]

Yes! Drop me a message via my web form, let me know where you are in Europe and I'll send you a local recommendation.