I bought this portable audio recorder as non-functional, hoping for an easy repair. But I got something else
It freezes at the startup screen, or at the "connect as USB microphone" menu. If I had to guess, I'd say a firmware update was interrupted.
But I cannot re-flash the firmware because that screen doesn't come up either.
On
zoomforum.us a similar problem is described and an answer from their support is quoted:
Interesting problem. Not one I've come across before. Certainly not with links to iTunes. The only occasion that was somewhat similar is when a customer performing an upgrade used failing batteries that caused corruption of the Boot Program. That unit had to be fitted with a new digital main board (DMB). The only customer repair procedure, renewing its system file, he's done. The unit will need to be returned here for service , labour will be £ 33.00 and parts as necessary. Worst case, a new DMB, £67.50. Best case, re-programming the flash RAM boot file on that board, £0.
I asked again (because the post above is 6 years old) but didn't get anything.
Thank you for contacting us with your question. Unfortunately we do not have any service manuals or schematics available for our products, nor do we have any component level technicians who would be able to assist with this service.
So I guess I'm on my own ... or am I?
Well I have taken it apart (beautiful construction, made in japan) and underneath the SD card slot I found a TI TMS320 DSP and a rather large flash chip (cFeon 16 Megabit (2048K x 8-bit / 1024K x 16-bit) Flash Memory
Boot Sector Flash Memory, CMOS 3.0 Volt-only) Well the latest firmware update file is about 14.6 Mbit, so it might just be what I was looking for ...
I also have a few high pin count devices like an Arduino Mega and an FPGA board, so I think I should be able to talk to that thing.
But here is my problem: I bet the
firmware image is encoded somehow or needs to be written to certain locations in the memory.
And before starting to solder in 48 tiny wires I thought I'd ask if I am on the right track at all ...
Thank you
On another board there is also a
NEC 78k0 series microcontroller. It might be there only to operate the LCD and the buttons while the TMS320 runs the show, or it might the other way around and the TMS320 does only DSP things ...?