MIDIbox MB-6582 Operating instructions

2020/11/16 14:13 1/4 MB6582 Control Surface Troubleshooting
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MB6582 Control Surface Troubleshooting
This section is about the MB6582 control surface trouble shooting based on the PCB version 2.0.
Please note that inappropriate working control surfaces may have a fault on the control surface PCB
as well as on the Base PCB. Therefore it is important to disconnect the CS PCB from the base PCB in
order to separate the root causes of the various possible faults.
It is also recommended to use this guide to verify the function of your control surface during the build
process. This will help you to identify faults early during the assembly process and will make you live
easier while testing the completed synthesizer.
The following acronyms are used in this section:
CS = Control Surface PCB = Printed Circuit Board
There are different root causes on the CS PCB leading to an inaccurately working control surface.
Please find an overview of the most common faults:
Shorts → caused by the midiboxer
Bad solder joints → caused by the midiboxer
Defective components (switchsed, LED, diods, encoders) → component manufacturing issue
Broken interconnection points (between the bottom and top side) → PCB manufacturing issue
Shorts or breaks on the boards → PCB manufacturing issue
The first step to do a successful trouble shooting is to understand the design of the CS PCB. Attached
you will find an overview of the usage of the connection pads between the CS and the Base PCB:
Please note that the all switches and all LED’s are sharing the same GND pad JD8 ! This is important
to understand because if you have shorts between JD8 tracks you will find that a series of switches or
LED’s are not working properly. In this case the MB6582 firmware will not be able to distinguish
between switches connected to the faulty tracks. Also all the LED’s connected to the faulty tracks may
light up together. It is also very helpful to understand that the encoders are using exclusively the
pads JD1 to JD4 as well as JD9 ! If you find encoders working inappropriately you just need to check
the rails on these pads.
The following steps are recommended to be carried out during the trouble shooting. Please make sure
that the CS PCB is NOT connected to the Base PCB !
Check of the single components:

Last update: 2012/04/25
19:08 control_surface_troubleshooting http://www.midibox.org/dokuwiki/doku.php?id=control_surface_troubleshooting
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LED’s → Check all the LED’s on the CS PCB. This is necessary to check that they are all oriented1.
appropriately and functioning as expected. To do this you can built yourself a cable that you
connect to the LED connector on the Base PCB.
Switch Diodes → Use your Multimeter to check that all the diodes are working properly. You just2.
need to select the diod test function on your multimeter. You need to connect the anode to the
plus (red) lead and the cathode to the minus (black) lead. The multimeter will show you the
forward current. Even the cheapest Multimeters offer a diod test mode to check switch diodes.
Check also the orientation of the diodes. The black stripe on the diode should match the bar at
the end of the arrow symbol on the CS PCB.
Switches → Check the “routed through” connection on the long sides of the switch. Then Check3.
that each switch is closing when pressed as expected (short sides of the switches)
Once you have checked the components separately you can continue with testing the function and
connection of each component. The following overview tables will guide you through each component
to be verified:
LED Assignment Matrix
Switch Assignment Matrix
Encoder Assignment Matrix

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Check the function of each component on the CS PCB:
LED Matrix –> Use the cable described in point a) above to check the wiring from the1.
connection points. You need to connect the GND wire to one connection point on the JD8 pad
and the +5V wire to one connection point on the JD6 pad. Please use the LED Assignment
Matrix shown below. You need to check all 64 combinations to make sure that the complete
matrix LED’s are working appropriately. During this test only single LED’s should light up. If
more than one LED’s lights up then you have got a short on the PCB.
Indicator LED’s → Use the cable described in point a) above to check the wiring from the2.
connection points. You need to connect the GND wire to one connection point on the JD8 pad
and the +5V wire to one connection point on the JD7 pad. Please use the LED Assignment
Matrix shown below. You need to check all individual LED’s to make sure that they are working
as expected. During this test only single LED’s should light up. If more than one LED’s lights up
then you have got a short on the PCB.
Switches → The function of the switches can easily be tested with the diode mode on your3.
Multimeter. You need to connect the GND wire of your Multimeter to one connection point on
the JD8 pad. The positive wire (red) has to be connected to one connection point of the JD5 pad.
Please use the Switch Assignment Matrix to identify the correct connection point on the JD8 and
JD5 pads. You should now press down the switch and check on your Multimeter display if it is
working appropriately. With this check you won’t be able to identify shorts on the GND part of
the board. To exclude shorts on the JD8 GND pad you need to measure the resistance between
each connection point on the JD8 pad.
Encoders → The encoders are connected to the connection pads JD1 to JD4 as well as JD9.4.
Please refer to the Encoder Assignment Matrix and the Base PCB / CS PCB Connector Overview.
You can used the continuity mode (2K Scale) to check the encoders. You need to connect the
wires from the Multimeter to the connection points of JD1 to JD4 as well as JD9.
If you haven’t found any faults so far you can start testing your CS while connected to the Base PCB.
Please use the following verification sheet to test the function of each component of the control
surface:

Last update: 2012/04/25
19:08 control_surface_troubleshooting http://www.midibox.org/dokuwiki/doku.php?id=control_surface_troubleshooting
http://www.midibox.org/dokuwiki/ Printed on 2020/11/16 14:13
You should walk through all components ! Please document your test results on the validation sheet
in order to support the later troubleshooting in the forum.
From:
http://www.midibox.org/dokuwiki/ - MIDIbox
Permanent link:
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Last update: 2012/04/25 19:08