VERSION 1.0
MPG-70 DIY KIT BUILD GUIDE
Page 1: ...VERSION 1 0 MPG 70 DIY KIT BUILD GUIDE ...
Page 2: ...th a soft cloth and some water to remove any resi due from offgassing of the enamel This may not be necessary but it is recommended Once cleaned the panel and enclosure parts can be set aside PCB Assembly For the easiest assembly build your PCB in the order laid out in this guide Since some parts are close together such as in the power suppy assembly will be easiest if you as semble in a particula...
Page 3: ...inspect your work and be sure that there are not pins shorted on U13 Once the main processor has been soldered and the flux has been cleaned move on to soldering the ceramic resonator Though the resonator is small it is not difficult to sol der Apply flux to the 3 solder pads on the PCB and using tweezers place the resonator Orientation does not matter With a bead of solder on the tip of your iron...
Page 4: ... or to have a cold joint on a mux pin When this happens it will cause multiple parameters to flash across the display or the param eter associated with the unsoldered pin will flicker on the screen as you toggle other parameters For best results check your work using a microscope or other magnifica tion The opto isolator is SMD but the legs are bulky and they will absorb heat This means that you s...
Page 5: ...citors according to the BOM Do not place any electrolytics yet When you have reached this step clean all of your work of flux Now place the 22uF and 10uF electrolytic capacitors Do not place the large 680uF and the large inductor These parts get placed last STEP 4 SWITCHING REGULATOR This step is very important The regulator is the key to getting stable readings and sta ble operation Start by usin...
Page 6: ... attached to the panel accessing the top side of the board will be impossible STEP 7 SLIDERS AND ROTARY POTS In this step we must place all of the sliders and all rotary pots EXCEPT THE 2 TALL TRIM MERS AND ENCODER Note that we are NOT placing the 9 switches the two tall trimmers the encoder and the 3 red LEDs yet This comes later When all pots and sliders are placed use your soldering iron from t...
Page 7: ...the front panel for attachment to the PCB Begin by gathering the 5 long screws the 5 threaded standoffs and the paper spacers Depending on the kit you have either blue paper spacers or brown cardboard spacers If you have blu spacers use 4 spacers under each standoff and thread through the panel as shown be low ...
Page 8: ...RETROAKTIV MPG 70 OWNER S MANUAL 8 ...
Page 9: ...e to prepare the screen to be placed The screen has 4 pins that must be trimmed to be flush with the PCB This is so the pins do not make contact with the met al front panel The pins should be cut using angle cutters and should be flush as shown below ...
Page 10: ...o make sure that the switches and pots that aren t yet soldered do not get pulled rom their holes When the panel alls into place use the nylon nuts to hold the PCB to the protruding 5 screws under the board Now adjust the 3 LEDs so they re poking through the rectangular holes Don t solder yet Be sure that the PCB is sitting firmly on the standoffs and is not catching on any thing Now go down the r...
Page 11: ...t leg in the square hole It is recommended that you solder one leg of each LED first then make your height adjustment and solder the remaining pin when the LED is placed correctly To solder the screen place the panel face down and allow the screen to sit flush with the panel The glass of the screen should be flush with the rear side of the front panel ...
Page 12: ...t adapter you may connect the board to power using this Other wise use the included 6P DIN cable The kits comes with 2 DIN plugs and a length of 5 conductor cable Begin by disassembling the DIN plugs There are 4 pieces in each plug assembly A rubber sleeve the male plug and two halves of the clamshell plug assembly Look at the rear of the male plug and you will see 6 hollow concave pins each with ...
Page 13: ...urn the unit on and you should see the power indicator light up Use a scope or meter to see the voltage between ground and VCC It should be about 4 7VDC Observe the power for a bit and make certain that it is stable A noisy or unstable supply can cause the programming of the processor to have issues or worse make it impossible for you to FLASH the program STEP 11 PROGRAM CPU The CPU must be progra...
Page 14: ...THE MPG70 BOARD TURN THIS OPTION OFF OR YOU RISK DAMAGING STUFF In the command prompt use the following line of code and press ENTER avrdude exe p m128 c usbtiny U lfuse w 0xce m U hfuse w 0xd9 m U efuse w 0xff m This line of code sets the Atmega128 clock source to use the external resonator and it sets up the chip to the configuration used in the MPG70 Next we need to tell the chip to allow us to...
Page 15: ...ed avrdude exe p m128 c usbtiny U flash w MPG70R1V37 bin Do not interrupt the ISP programming when the program is reading writing Doing so may disable the Atmega128 s ability to be flashed which will require a special tool to resurrect Avoid doing this at all costs NOTE As of the time of this writing the OS revision is 1 37 The bin filenames in the commands above must match the file names of the E...
Page 16: ... you will also see this behavior Buttons don t work check the soldering of the CD4051 Check that no diodes are back wards Check address pins and enable pins of 4051 and trace them back to the proces sor Look for bridges and pools of flux If there is a diode that was in backwards chanc es are it destroyed your 4051 Replace that and the diode and try again LED s flickering Check your power supply co...
