ASSEMBLY_INSTRUCTIONS_MUST_READ!.txt

MK312BT Hardware Assembly Notes

1) Trim Potentiometer knobs to correct length if desired
2) Use black permanent marker to black out front panel hole walls if desired 
3) Cut the tabs off of the base of the pots so the board sits flush with the display facade if desired
4) To correctly fit LCD - solder header to LCD board first. Next insert LCD panel into front panel daughter board. Then put screws on front panel facade and finger tighten M2.5 screws first. Adjust positions as needed so everything lines up and sits well. Finally solder LCD header to front panel daughter board.
5) Make sure Pin 32 (LED2) on the HC-05 module is actually soldered and making connection to the ZS-040 break out board or "Radio" LED may not function on the front panel
6) Be very careful not to bridge pins when soldering the LM 2941 (U14). Apply heat to 1 pad only and carefully apply solder. If a bridge occurs - remove the IC, clean the pads throughly with flux and solder wick and then retry.  Pins 2 and 3 can be bridged because they are both ground. Ensure that no other pins are bridged. Check with multimeter continuity tester for bridges before power on!  
8) Make sure to check the orientation of all electrolytic caps. (+) indicates the positive and a solid white "|" indicates the negative .
9) MAKE SURE YOUR POWER PLUG IS CENTER POSITIVE OR THINGS WILL GO BADLY. If you fuck up and plug in a reversed polarity supply - replace electrolytic caps C1 and C4.
10) Please remember to adjust the LCD contrast potentiometer - if incorrectly set the unit and backlight will power on but the interface will not be displayed. 
11) Place transformers with P facing the output jacks (yes we are using the transformers "backwards" if you follow orientation given in the transformer datasheet )
12)Trim pins of 4066 IC (U3)  Socket on the front panel board flush before soldering so buttons can clear. If the buttons still interfere, carefully disassemble the button and cut off the bit of the plastic housing that interferes with the 4066 IC socket pins.
13) Using side cutters cut off the screw boss/screw mount on the case that touches/interferes with the ribbon cable socket on the display board.
14) The LCD display has metal retention tabs that may short the soldered leads of C43. When installing the display board ensure that this does not happen (shorten the capacitor leads and bend the offending metal tab out of the way if necessary