Fixing the controller (RepRapDiscount)

[EBankert]

So I covered some of this information in another topic as a side-note to the main issue (z axis driver was busted), and I am still struggling to find a solution to this problem. Here goes:

- The LCD screen works perfectly fine
- The Speaker works fine
- The reset button does not work (at all)
- The control knob button press works, but I cannot scroll through the lists
- The LCD screen cycles through a continuous resetting process (Displays startup screen, then displays the home screen)

Note: I found that the person who built the printer had one end of the 10 pin connector to the LCD on backwards, so I just flipped it around on the Rambo Board. Before flipping it, the screen would not cycle through the startup and home, but every time I tried to scroll through the menu, the machine would home and reset.

Note 2: In the configuration.h file, I have the LCD type defined as "13"

Note 3: IT IS NOT OFF BY ONE PIN. I have checked this. multiple times. repeatedly.

Any help is appreciated!

[Xenocrates]

This is the Reset button on the Rambo itself, rather than the LCD controller, or is there a separate reset on the LCD board? (I haven't used it in a while, after the reset button on the Rambo died and put it into a reset loop, which I ripped it off to fix, but by then I had a Duet so I didn't bother putting it back).

[Eric]

Generic schematic of a reprap controller: http://reprap.org/mediawiki/images/7/70 ... scount.pdf

One cable connects speaker, knob press, and lcd. All things you say are working. Also VCC(5V power) and GND are on this connector (which in turns provides 3.3V power for the SD card).

The other connects knob rotation, reset button(which is a software function, NOT the rambo hardware reset button), and the SD card. If this cable were flipped, then knob rotation would be triggering the reset line. Which matches what you say was happening.

Things you can easily check:

The adapter board. Remove it from the rambo board and examine all the solder joints for defects. We had at least one past case in this forum where someone had a solder bridge between pins.

The 10-pin cable. Examine it for any obvious flaws. Get a meter for continuity tests, a couple bits of wire to poke in the connector, and check that pin 1 is actually connected to pin 1 on the other side. Ditto for the other 9 pins.

The reset button. With cables disconnected, measure between the diagonal solder points right at the switch itself. When you operate the button, you should get continuity. Yes, it might be easier with 3 hands.

The rotary knob. Test with cables disconnected. On one side you'll see 3 pins soldered to the board. Measure between the center and the bottom pin. Rotate the knob slowly. You should alternate between continuity and open. Same test between cneter pin and top pin. One again, 3 hands helps. If both of these pins show activity, odds are the knob itself is functional.

[rurwin]

The 10-pin cable. Examine it for any obvious flaws. Get a meter for continuity tests, a couple bits of wire to poke in the connector, and check that pin 1 is actually connected to pin 1 on the other side. Ditto for the other 9 pins.

You should also check for shorts between two adjacent cores. Either open or short is a significant possibility with IDC cables, especially if they have not been machine-made.

[EBankert]

I tested all of Eric's Ideas and everything seems to be working fine. It is still just randomly resetting without any user intervention. I am beginning to think it is a software problem. The cables are fine, I tested for breaks and shorts. The button and rotary knob work fine. Could it just be a random short somewhere else in the machine?

Thank you for the replies!

Update: Every few times it restarts, I manage to time it tight to be able to scroll to see the filament used and print time menu. I cant test any functionality because it keeps resetting. The reset button works too.

[Xenocrates]

See if the reset button on the Rambo makes an audible click. If not, try removing/desoldering it. I had around the same symptoms when it failed

[EBankert]

https://www.youtube.com/watch?v=2avJzipVdKk

Here is a video of the problem

[Eric]

Does the machine behave via computer control on the USB interface? No resetting?
If not, disconnect the reprap cables and try again. If it still misbehaves, your issue has nothing to do with the reprap controller.
If it behaved, then try just the LCD cable connected to see what happens.

[EBankert]

I took off cable B, and the LCD works fine, as well as the button in the rotary knob. Nothing else works because they are not connected. I tested the reset button, and it was not shorted. Could it be a pin configuration issue in the firmware?

[Eric]

If it were me, I'd refer to the schematic I linked earlier and hook up individual pins on the B connector until I found which one(s) caused issues. There's only two pins needed to get knob function. One more for the reset button. And there's 5 for the SD card.

But then I have plenty of single-pin jumper wires on hand. I don't know how well set up you are for such things.

Um, I don't supposed an SD card was left in the slot? If so, remove it. It would be amusing if a bad SD card was the cause of all your issues.

[EBankert]

I could never do something so stupid... Ha...he...

It was a faulty Micro SD adapter I left in there.
The whole thing is working... for now!
Thank you for all the replies and help!

Edit: Now the temperature is constantly overshooting when doing an auto-tune. I ran M303 S200, with PID max tuned down to 128, and I got the same result as if it was set as 255. Is there another setting that I can change to stop it over-heating. (It goes to about 221-223 degrees)

[Turpinator]

When I first built mine, it would always overshoot. I took a large fan and blew it on the hotend area to tune it the first time. After that I did a tune again and it worked without overshooting.

(I think this was a suggestion in the V2 instructions too)