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veloper
10-22-2021, 08:36 PM
Hello everyone,


Background


This is my first post so I'll try to provide as much detail as possible so as to respect your time. I'm a hobbyist / tinkerer in my spare time with a background in computer programming. Recently I acquired a confirmed-working BizHub7228 that I've since completely stripped down for part & components.


Steps Taken So Far...




I started off by using a multimeter to probe the DCPS blindly; attempting to map out the voltages and groundings coming off the various leads.
I couldn't find the 24vdc leads so I started researching possible causes.
Tried to lookup the board manufacturer (Matshushita Electronic Components(H.K.) Co., LTD.) and part numbers (27LA84510, ETXKN495ACF, no. 5524V) for any kind of datasheet -- found nothing useful.
Tried checked the physical manuals -- found nothing useful.
Finally searched online for the printer model and found a "Service Manual" that explains why I couldn't find a 24vdc lead...

The SW2 (Sub power switch) is located on the PSW2B (Power SW2 board).
Upon the SW2 on, an ON signal is sent from the SW2 to the SCB (System control board) through the OB (Operation board).
As a result, the SCB sends a control signal to the DCPS (DC power source),
thus causing the DCPS to supply +12VDC, -12VDC (7145 only) and +5VDC to all of the boards and options, including the CB (Main body control board).
The SCB (System control board) then sends to the DCPS (DC power source) a control signal
that causes the DCPS to generate +24VDC.
This 24VDC power is supplied to all of the drive boards and options.
(Quote from manual; Format and emphasis mine)


I looked back at wiring of the DCPS trying to find a path for this "control signal" to be sent through.
My best guess is a bank of leads labeled as such...

3-1 RL CON
3-2 L2 CONT
3-3 L3 CONT
3-4 24V EM
3-5 FM1 EM


My next best guess is that "3-1 RL" pin is the right path to send the signal, as RL might be short for "Relay"



The Problem


I can't find a solid definition of "control signal" within any of the manuals I have. I'm not familiar enough with circuit-board-level engineering to really know how to generate the "control signal". My best guess is that the "signal" is a momentary circuit made from one of the SW1 (offline) voltages (12v or 5v) to that "3-1 RL" pin. At this point I really don't want to just start routing voltages to pins I don't understand.


Questions




What is a "control signal" as defined in the service manual?
Is it possible to emulate/reproduce this "control signal" without the SCB, OB, and PSW2B components being involved?
Where should that signal be sent to on the DCPS?
Is there a different solution that I should explore instead? (that does not involve the SCB, OB, and PSW2B components)



Additional Resources


The Service Manual and various images of the components can viewed here on dropbox: Dropbox - BizCenterResources - Simplify your life (https://www.dropbox.com/sh/0t0z2z01pc2pthb/AABEhvnxsxPHFhUsy_ZkvxV6a?dl=0)


---


Please let me know if there is any other information I can provide that would help solve my problem.


Thanks in advance for any help.

Synthohol
10-22-2021, 09:01 PM
If you have the real service manual look in the appendix.
Shows the wiring diagram and all the connectors and voltages.
Unless I'm not understanding the question.

veloper
10-22-2021, 09:23 PM
Thanks for the reply Synthohol.

Yes, I've looked at the real manual (it's in the dropbox link) and that's how I've determined what I _think_ might be the way to turn on the DCPS without involving the additional boards.

The wiring diagrams start from page 442 to 444 in the linked manual. The voltages for the "control signal" are not listed in the manual as far as I can tell.

Here's a screenshot of the manual page with the wiring i'm suspecting turns on the DCPS' secondary power terminals (RL CONT)

50544 50543 (2nd screenshot is the SCB)

The appendix does not seem to reference it

50542

Thanks again for any help.

Synthohol
10-22-2021, 10:27 PM
may i ask why?
if you are just tinkering i get it, if you are trying to do something with the copier, dont blow up or start fires.
if you want a real 24v powersupply just buy a meanwell, they are top notch :)

veloper
10-22-2021, 10:59 PM
may i ask why?

Asking why is totally fair!

In this particular case I'd like to recycle this for use as (my first) multi voltage and multi-outlet benchtop power supply.

Some of the reasons I'd like to do that are:



It has a nice array of common voltage outputs and decent amperage (24V 2.5A, 24V 10A, 5V 5.5A, 5V 4A, 12V 0.3A, 12V 0.5A) DC + (2 x 100-127V 6.5A AC)
I know it can power every single solenoid, fan, and motor I've scrapped from the printer.
It looks pretty easy to build it into an enclosure with various terminals and display meters.
When / if I get an actual variable bench-top power supply this can still be used to power an independent project.
Looking for something that just provides 24 Volts at 10Amps runs about $20 and again, i'd like more voltage options.

Additionally, I'd rather put that money towards something of better quality later down the road.






if you are just tinkering i get it, if you are trying to do something with the copier, dont blow up or start fires.

Yeah, planning on tinkering with the motors, solenoids, switches i've pulled out. No solid plans or ideas yet but i get more enjoyment out of the building & learning than the final product.

Also, 100% hear you on safety. Workspace is clear of flammables, proper PPE is always worn, and fire extinguisher is mounted in an unobstructed area.



if you want a real 24v powersupply just buy a meanwell, they are top notch

Totally checking out 'meanwell' now for a "later down the road" solution :)

blackcat4866
10-22-2021, 11:58 PM
Yes, that's my question too.

What symptoms? What are you trying to fix? You skipped over that part.
=^..^=

Synthohol
10-23-2021, 12:19 AM
geek project ;) not for copier.

veloper
10-23-2021, 05:44 PM
may i ask why?


Asking why is totally fair!


In this particular case I'd like to recycle this for use as (my first) multi voltage and multi-outlet benchtop power supply.


Some of the reasons I'd like to do that are:


It has a nice array of common voltage outputs and decent amperage (24V 2.5A, 24V 10A, 5V 5.5A, 5V 4A, 12V 0.3A, 12V 0.5A) DC + (2 x 100-127V 6.5A AC)
I know it can power every single solenoid, fan, and motor I've scrapped from the printer.
It looks pretty easy to build it into an enclosure with various terminals and display meters.
When / if I get an actual variable bench-top power supply this can still be used to power an independent project.
Looking for something that just provides 24 Volts at 10Amps runs about $20 and again, i'd like more voltage options.
Additionally, I'd rather put that money towards something of better quality later down the road.







if you are just tinkering i get it, if you are trying to do something with the copier, dont blow up or start fires.


Yeah, planning on tinkering with the motors, solenoids, switches i've pulled out. No solid plans or ideas yet but i get more enjoyment out of the building & learning than the final product.


Also, 100% hear you on safety. Workspace is clear of flammables, proper PPE is always worn, and fire extinguisher is mounted in an unobstructed area.





if you want a real 24v powersupply just buy a meanwell, they are top notch


Totally checking out 'meanwell' now for a "later down the road" solution


---

Well, after some private messaging from blackcat and synth it seems like it's not as simple as jumping pins or pumping voltage somewhere to turn on the secondary power on the DCPS.

So... I ended up reconstructing the wiring I cut during the teardown/scrapping. (Don't be me guys; don't cut your 28 pin connector wires!)

Once I plugged all 4 boards together the magical 24vdc fan started up on the power supply. Next step is mapping out voltages and coming up with a suitable / safe housing.

Pic of the "zombie" power supply...

https://previews.dropbox.com/p/thumb/ABVQM08uS76nB7wzva4RXz0qnnUDRY3j0F4m-eumALEYUIWJwKW7XvUanzU4SdpLsZlOuT3nuY9rJ70m_4d_VJ7 LsCmcyoSKQ85bp7Lsj5mERu2UL6tm-rfgP326djf_LezDwlOW0V9Y2ySu22s1tkMO20vIM2fSeYGF7rf 9rQQjWkCKnW9Lda_pZa4etWBdejZFYPaCEs1fMTTbYT9JXkDEJ KLJx9PFHbo0qCWvp847rtfUgz5Ep0jMuuhuoqhMlNLgaizTmB4 5V6sIvreeBjNepCXdrF7YBNTXrFRBKuKf71Z2si3g3gOxJfLd-l72uaMaBIjXpbyw5lJBpwr046nWCx-c63eaQP4QFOoX9P-8y7e-NHPT_88cMATdaGPP_bXhIttbdLA3yX_f5GURGR5ebFc5Zl4yvS MofuffawKPgg/p.jpeg?size=2048x1536&size_mode=3

blackcat4866
10-23-2021, 10:32 PM
I created a "copier in a box" from a Sharp Tiger AR-M280.

This particular model had spare DIMM sockets on the controller allowing the copying of the firmware DIMMs. So I scrapped the engine and neatly layered the boards and 18ft of wire harness into a plywood box, with an easily accessible portal on the top to load DIMMs. I noticed significant heat, so I connected a couple of muffin fans to cool it off. With the operation panel fitted to the front, you could follow the DIMM copying process, and the boards never even noticed the the printer was missing.

I can't take credit for the idea, though. In one of my classes, one of the instructors had created such a beast, and showed us how to copy DIMMs. A year later I couldn't resist trying myself. =^..^=

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