Trying to help ya out, because I've been there before.
Something you might try to do, would be to contact Seiko Instruments
Inc, whom I believe is the manufacturer, directly; the FCC ID seems to
confirm this:
https://fcc.report/FCC-ID/C4Z7NSTK06011
...but not much else (sometimes, when a device is FCC registered, you
can find all kinds of info that the FCC keeps on file about it, as it
wends and winds it way thru the registration process; technical manuals,
user manuals, etc - and if the FCC does certain testing, you might even
find internal photos, and other things; it's a great "go-to" place for
things like this...
BTW - I got this FCC ID from a photo of a DPU-40 I found on Ebay - maybe
there is another version?
https://www.ebay.com/itm/326280347705
...to continue, though...sometimes, like in this case - you find
nothing, unfortunately - except confirmation of the manufacturer. I
don't honestly know why this sometimes happens, because one would think
that when you start the process, there would be more than just this
singular application record and nothing more. Unless there was a more
lax process back then (1980s?) and/or the records were lost, not
digitized, or something else? That said - here's another oddity - I
found this manual for the "DPU-30" (which should be the model before the
DPU-40, right? Well...):
https://www.mouser.com/ds/2/360/DPU30_Technical_Reference-8285.pdf
This manual shows a much more modern-looking thermal printer - and a
manufacturing date range of the early 2000's - so, maybe they re-used
model #s for the product range (much like the Ford Ranger pickup truck
thru the years, when at one time the "Ranger" was a 4-door car, IIRC -
1950s or 60s?).
Something you can also google around for, which might help you find
something (I'm still looking) is "Seiko DPU series pdf" - of course, not
knowing exactly which printer you have (the old 1980s model? Or
something newer?) - hinders my searching a bit (there is, for instance,
some newer "DPU-414" mobile printer - but I don't know if anything about
it would relate to your printer).
Something you might do (well, I'd do it - but you'll need to decide if
you'd feel like it ) would be to open the thing up, and see what's
inside the printer - take a bunch of photos, there might be some
markings or numbers that can help - gather as much info as you can. Of
course, this is only of use if you plan to do much more than what you
are doing, of course - but anything can help in the future. Also, gauge
on whether you want to do this or not based on your level of comfort
with tearing down things...and then putting them back together (just
keep in mind, mainly, that if something doesn't want to come apart, to
stop, and step back, and re-assess what you are doing - there is usually
a reason why something won't come apart easily - and forcing things
could break them).
I'll post a follow-up to this if I happen across anything more...but I
hope what I have here will help. Again, though: Contact Seiko
Instruments Inc (SII is also how they are referred to). Just also keep
in mind that you'll likely be contacted the rest of your life from them
for various things (I'm on their list - or maybe it was Casio - or Sony?
I forget - but some old piece-o-junk I had landed me on an email list
which so far, has seemed impossible to get off of).
Andrew L. Ayers
Glendale, Arizona
phoenixgarage.org
github.com/andrew-ayers
