EEVblog #641 - Dumpster Cash Register Teardown

Teardown Tuesday.
Dave tears down a cash register found in the dumpster.
Does it have any useful parts to salvage?
German brand Quorion QMP 3282
And a look inside a thermal print head.

Datasheets:

EEVblog Main Web Site:
EEVblog Amazon Store:
Donations:
Projects:
Electronics Info Wiki:

[electronicsNmore]

I would love to see a photo of Dave inside the dumpster with just his knuckles over the top edge and the very top of his head/eyes looking out. Too funny. Like, "Kilroy was here".

[AJMansfield]

For a bodge though, that is a really clean, well engineered one. They actually bothered to put a connector and everything.

[tubical]

Cool teardown, Dave! Tanx for this one. I like the VF Display best, as it is a very big one...;)

[johnfranks]

Dave, I would be interested in a episode dedicated to "the art of the bodge."  Like what exactly were the symptoms before the mod, how easy is to replicate the failure, why the problem wasn't identified before production, the costs involved, the terror, finger pointing and other drama behind the scenes when you suddenly discover you just 10, 000 units that don't work, etc. 

Every time I see a bodge on a board, I can't help but think "Man, somebody had a BAD day!" 

[CH_Pechiar]

Dave, your comments about bodges on this German product are much more measured than your screams when you see bodges on Asian stuff. The PS is looks really good though.

I love the Tek USB stick beside the scope at the back!

[Coolkeys]

It would have been nice to see the power up sequence, as you described it was quite interesting. Also the software on those devices is at-least as important as the hardware. It's nice to see how displays are used, how bright, character set etc, and it's nice to hear how piezo sounders are used. "Don't turn it on take it apart" only works when you reassemble the device and power it up afterwards :-). A tear down on dead device is only so interesting, if it's broken of course there no choice. Thanks for posting.

[TheAwesomeManDan]

That cutter assembly could make quite a nice tape dispenser for PVC or Kapton, for those times when you need three hands.

[kristinaification]

I've heard that most places don't actually keep any money in their cash registers after they shut down for the day, so the fact that the register wasn't secure probably wasn't actually a problem.

[The-Student]

Thanks for the tear downs! I enjoy ever single one of  your videos. First the scanner and now the register, complete convenience store package.

[nshex]

Hi Dave! Long time viewer, first time commenter, I have used many different cash registers:
1. yes, they all have some dingy tab to open the drawer, but only if it is unlocked (it only overrides the solenoid)
2. The key you found is for changing the mode, not locking the drawer. The modes are normally: Program, normal, void, off. one key (user) will let you turn it on and off, the other (admin) will let you program it and void sales. This is why it is not a really secure key.
3. programming these things is only slightly better then a root canal;
Put in PGM mode
enter 1001 press PLU then 1100 press PLU then AM/TD
Enter 1011 Press PLU then turn gey to Void and press AM/TD
and so on and so on. it is horrible.

[Jellow]

I like the idea of reverse-engineering the display interface :-)
Hey Dave I think this would make a nice video. Perhaps with a fundamentals Friday about logic analyzers and different protocols in general.

If you're the same opinion leave a comment or a thumbs up to make Dave aware of.

[swc]

Toilet paper dispenser with a cutter mechanism.

[carlosgranados]

Thank you so much! I finally found out how to separate the top part from the bottom drawer! Excellent! So, I can now use only the drawer while I take the top part to fix.

[unclefreddy]

While I am a rank beginner with electronics despite years of messing around these are fascinating. Dave is the man!

[insme]

I don't really get what is going on in your videos, yet I still watch them. Wonderful.

[TheWinnieston]

This is really cool. As I work for military defense, all this "afterthought circuitry" is a real thing and hasn't gone anywhere! Sometimes we have to get a product out, and scotch tape and lead solder is the only way!

[LynkedVideos]

Fantastic find, Dave. That vacuum number display is excellent! I always enjoy your videos.

[SBG]

The EEVBlog, Teaching people how to rob cash registers since 2014.

[joinedupjon]

wayback old cash registers used to be a way of getting a cheap uc training system, when the very first casio electronic registers (more basic than that one) started getting dumped (mid 80's ish) someone had produced a prom with a monitor program on it which you sent off for to an address in an electronics magazine advert - pre youtube hack!
you had to assemble your machine code by hand and type it in through the keypad byte by byte, the VFD was your visual display and iirc there was no long term storage for your work. We had one at school - it worked but you only had about enough time to flash a led before it had to get switched off again at the end of a lesson. by that time a lot of kids had BBC and sinclair micros at home anyway which made it seem pretty unimpressive.

sorry for waffling up an old vid, just thought the people who've grown up on arduinos etc might be interested

the circuit board on that looked surprisingly clean given it had been used in a cafe

[isscv]

Very nice Dave!
I really love your teardowns, which i myself already did as a kid.
BTW, i think the cutter mechanism doesn't cut the paper completely, in the middle there would be a little spot left uncut. Then you would have a chain of receipts instead of a bunch of individual sheets of paper.
Keep up your style!