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Hi Mark
Tnks for your prompt answer.
The initial diagnostic ends with a green light, the motor then starts after 4 secs. and keeps on Rolling :- ))
The thermistor has been replaced with a fix resistor
Anyhow, right now, in Europe, we are in the middle of Christmas Hollydays, the equivalent of Thanksgiving. That means I'll have plenty of time to trace back all the mods and check all the wires . I hope I'll found the bug before Friday.
I'll keep you informed. I'm sure it's something stupid and obvious (as most of electronic problems are).
Tnks again
Marc
Hi Marc,
It will take me a few days to get to this, probably Friday. I'll get back to you. When you turn the printer on does it go through its initialization and finally stop with a green light? I'm at my office now so I don't have the printer in front of me, but it's supposed to initialize with green lights moving back and forth, then the motor starts and runs for 20 seconds or so, then it stops with the ready light green.
Did you replace the thermistor with a resistor of about 2.5K (2k5)?
Mark
-----Original Message-----
From: "Marc.olanie@... [Homebrew_PCBs]"
Sent: Dec 22, 2014 10:12 AM
To: Homebrew_PCBs@yahoogroups.com
Subject: [Homebrew_PCBs] DLP MCU version troubleshooting, help needed
At last, I finished the « hardware » mods and wired the MCU… So far, so good. But the rig don’t seems to work.
I’m checking again and again all the different options, but don’t see where my gremlin is hidden.
When I’m starting the printer, after the initial check (without any carrier in the NPIS), the green led lights on, and after 4 seconds the feeder starts rolling without interruption during 60 seconds. All led are flashing at the end of the sequence.
If I place a carrier in the roller at this stage (before the motor stops), the carrier his “slurped” thru the printer, and stop moving when the end of the carrier has passed the NPIS (2 inches away from the npis). To eject the carrier, I have to “block” the npis with a piece of pcb or whatever, and press on the “run” button. The sequence ends with a "paper jam" alert only.
Voltage measurements on the mcu board
Pin 5 of the MCU goes low when no carrier detected in the NPIS, high when obstructed.
5 V is ok on pin 8 (5.02V, perfect)
Pin 6 is high, goes low after approx. 1 second and stay low during 3 seconds when “X” or “run” is pressed
Pin 7 is high, goes low after approx. 3 seconds and stay low during 4 seconds when “X” or “run” is pressed
Pin 3 is high, goes low after approx. 1 seconds and stay low during 4 seconds when “X” or “run” is pressed
Pin 2 is high (3.3v), goes briefly low when “X” or “run” pressed, then back to high, and briefly low again then high when “X” or “run” released
None of these timing are accurate (counting in my head, looking at the scope). If more precise measurement should be done, I’ll have to build a “poor man’s logic analyzer” with a cypress or an Arduino and it will takes a little more time
The two blue wires coming from J27-4 and J23-1 are left unsoldered (should I cut ?)
Hope this checklist is accurate enough to help find a clue
Tnks
Marc