Thermistor terminal short - HELP!!!

[altarke]

The other day I had the thermistor create a short by having one of the hair like wire touch the hot head. As a result, at print time, I get the head temp to "run away" in the middle of printing and reach temps like 220C, in some sort of erratic fluctuation pattern. I tested the thermistor terminal on the RAMO board and it reads 61Kohms (I believe it needs to be 85Kohms). When I run the M303 s200 test I get "test failed temp too high".

In desperation, I connected the hot head and its thermistor to the 2nd head terminal output of the RAMBo, but it does not seem to register presence for the head, not can I control it. I suppose it may need some configuration changes somewhere to redirect/substitute the control from head 1 terminal and it fan and thermistor outputs to head 2 and it fan and thermistor.

I was wondering if anyone knows how to use the 2nd head terminal output (and its associated fan and thermistor ports) build into RAMBo board instead of the first one, and get it to work like before the short.

I am desperate - want to print and can`t -don't want to buy a new RAMBo card-Does anyone knows how to do it?

Thanks

[Eaglezsoar]

Pins.h is where the pins are assigned to the thermistors. I am not an expert at reassigning these pins but here are a couple of threads:
http://forum.seemecnc.com/viewtopic.php?t=1642&p=10387
http://forum.seemecnc.com/viewtopic.php?t=4024&p=26307

Ultimachine.com is the manufacturer of the cards and they do repair them.

If one of our superusers can help remap the pins in Pins.c please jump in and help.

[altarke]

Pins.h is where the pins are assigned to the thermistors. I am not an expert at reassigning these pins but here are a couple of threads:
http://forum.seemecnc.com/viewtopic.php?t=1642&p=10387
http://forum.seemecnc.com/viewtopic.php?t=4024&p=26307

Ultimachine.com is the manufacturer of the cards and they do repair them.

If one of our superusers can help remap the pins in Pins.c please jump in and help.

Thanks for your reply and look forward having one of the superusers jump in - I defentely have no idea how to do it. I can go into the pin.h, using ardinio interface, I had done this much in the past to calibrate the printer, but I need to know lots more to complete successful mod like that.

[Eaglezsoar]

Come on guys, I know someone is reading this thread that can help altarke remap his pins.h
Please take the time to help him out. I don't have the skills but I know a few of you do.

[altarke]

Come on guys, I know someone is reading this thread that can help altarke remap his pins.h
Please take the time to help him out. I don't have the skills but I know a few of you do.

U THE MAN

Thanks

[mhackney]

I thought I posted this morning - I've been having odd problems in the last few weeks where I write a reply, post and then nothing shows up.

Basically, I said that I had this problem and tell how to remap pins.h in my build thread. Go to the thread and search for pins.h in the Search Thread box at the upper left.

EDIT: here it is.

[altarke]

I thought I posted this morning - I've been having odd problems in the last few weeks where I write a reply, post and then nothing shows up.

Basically, I said that I had this problem and tell how to remap pins.h in my build thread. Go to the thread and search for pins.h in the Search Thread box at the upper left.

EDIT: here it is.

Thanks I actually done it but it did not cure the problem, still getting an error when issuing m303 s200 commend. But last night I decided to take a chance and print anyway - all all seemed well, I will have to decide what to do..............

[mhackney]

Interesting, I have a similar issue tuning my Onyx powered at 24V but never the hot end. Did you try tuning at say 180°C and see what happens? Perhaps the initial PID values are so far off that the temp overshoots significantly. When you run the M303, do you watch the temp display (either on the LCD if you have one or in Repetier Host)? If so, what do you see for the high temp?

cheers,
Michael

[dpmacri]

Interesting, I have a similar issue tuning my Onyx powered at 24V but never the hot end. Did you try tuning at say 180°C and see what happens? Perhaps the initial PID values are so far off that the temp overshoots significantly. When you run the M303, do you watch the temp display (either on the LCD if you have one or in Repetier Host)? If so, what do you see for the high temp?

cheers,
Michael

FYI, I don't think the temps show up on the LCD when you're running M303. But maybe my recollection is off

[altarke]

Interesting, I have a similar issue tuning my Onyx powered at 24V but never the hot end. Did you try tuning at say 180°C and see what happens? Perhaps the initial PID values are so far off that the temp overshoots significantly. When you run the M303, do you watch the temp display (either on the LCD if you have one or in Repetier Host)? If so, what do you see for the high temp?

cheers,
Michael

I will try m303 at a low temp and report

[altarke]

Interesting, I have a similar issue tuning my Onyx powered at 24V but never the hot end. Did you try tuning at say 180°C and see what happens? Perhaps the initial PID values are so far off that the temp overshoots significantly. When you run the M303, do you watch the temp display (either on the LCD if you have one or in Repetier Host)? If so, what do you see for the high temp?

cheers,
Michael

I will try m303 at a low temp and report

Well, I run it a m303 s185 and it still failed but the temp did not exceed 188c?????

What do you make of it?