thermistor errors

I am having a problem with my printer after replacing the Arduino mega board. Downloaded the German RepRap Protos V3 firmware all looked good but the thermistors for the heated bed and the extruder show def on the screen . I have put two new thermistors on To1 and T1 and still the same def .Any one out there have a clue whats going on ? Hope to hear soon ,thank you .

Where did you get firmware? so I can take a look at it.

Download this RAMPS T0-T3 test firmware compile it and uploaded to your RAMPS board.
Then start the serial monitor at 9600 baud

It will display the following

Initializing...
Simple RAMPS analog ports T0, T1 and T2 tester
A RAW value close to 1023 is unplugged
A RAW value close to 978 is type 1 at 25 degrees C
The RAW value will decrease as temperature increases
Starting test in 3..2..1..Started
T0 RAW value = 1023
T1 RAW value = 1023
T2 RAW value = 977
Next reading in 5..4..3..2..1..
T0 RAW value = 1023
T1 RAW value = 1023
T2 RAW value = 978
Next reading in 5..4..3..2..1..
T0 RAW value = 1023
T1 RAW value = 1023
T2 RAW value = 978
Next reading in 5..4..3..2..1..
T0 RAW value = 1023
T1 RAW value = 1023
T2 RAW value = 978
etc...

What do your RAW values show?

Edited 2 time(s). Last edit at 02/01/2020 07:21AM by Dust.

Hi there ! I got the firmaware fro German Rep Rap for the V3 .Its Repeiter Arduino
[germanreprap.sharepoint.com] think this is everything , thank you for replying ,Harry
[germanreprap.sharepoint.com]

Im trying to open your suggested download but my lap top keeps crashing ! I will be getting my Widows 10 equiped pc back tommorow and hope I can get all this sorted . As for the tech talk , Im sorry I a newbie and learning it all . But when I 3D print its pretty big stuff , I make motorcycle parts for oldtimers,well at least the caing moulds to cast the bits in alloy etc , just getting the printer thing sorted is very important to me and not just a hobby so I need all the help I can get . Ive been been printing for 3 years now and this is the biggest prolem Ive had ,

Using the firmware you linked above works fine on my test machine.

The firmware is very old and requires old arduino IDE. I used arduino 1.0.1

Start pronterface and connect it to the printer (250000 baud). Now press the reset button on the ramps board, it will display a full boot up log in pronterface
(Do not unplug the ramps from the usb as this will disable the serial port and stop pronterface from displaying anything)

eg I disabled the bed thermistor and the second hotend thermistor for this test.

start
Info:External Reset
Free RAM:4008
extruder 0: working
extruder 1: temp sensor defect
heated bed: temp sensor defect
Error: Printer set into dry run mode until restart!

Edited 1 time(s). Last edit at 02/02/2020 08:23PM by Dust.

So here we are ! Pronterface and all . I dont understand the hot bed sensor / thermistor defect .Its the thermistor defect , but I put another one on the two pinned T1 pins and it still reads defect.Does this mean the board that pins are on is defect ? Hope you can help ,and understand this

Since you have swapped thermistors there are only two possibility that remain

1) dead ramps/mega pins
2) its actually looking at t2. not t1

The second one you can easily test, put another thermistor on T2 and re test with Pronterface.

If nothing changes.. its a dead ramps/mega

Ok will order new , I will let you knowhow I get on , and thank you again , Harry

Ok I borrowed a ramps 1.4 ,I already had a new Arduino Mega spare, and got these Pronterface thermistor readings T0 raw value = 984 and T1 raw value = 982 ,I put a spare thermistor I had on T3 and got 981

ok now Im showing my lack of know how ! How do I open up the GRR Repeiter program with Arduino 1.0.1 ,when all it does is open in the latest 1.8.11 . I am at a loss .

And the screen has gone , its now just square dots !

Ok Dust ! Ive got it ! I think , got Repeiter on Arduino 1.0.1 ,fired up Pronterface on 9600 buad , showed me all three thermistors working . Put it all back together with a bare ramps 1.4 and three thermistors ,it just goes def with two ! Ok so far so good ,def gone ! Then start to put the drivers on Ex 1 , not def , X driver nothing screen out nothing , swap for new driver , screen on no def . Same with Y driver all out def etc , swap that all good .Z driver all ok .Put printer on power , instead of just USB all green !!! Then I move the printing table back and forwards to see if all the cables are running free and there it is a again "def" !!! But have noticed my little ring LED light around the hotend its not on ! Look closley see a cable loose put it of the metal and "def" GONE !!! So what burnt the drivers out , the LED shorting out ? I dont give a monkeys it looks like Im getting my printer back thanks to you ,I would buy you a beer ! But I bet you dont live this side of the pond ? Im a Brit living in Germany ! And you ? Thanks again , for your patience and brilliant tips , all the very best and I hoppe this all goes to plan !! :-) Harry

Ok its not ok !!! Running sweet now its "def" !!! Will try running on sd card , it seems its going offline and stopping it all :

Ok its me again ! Only top say the def was due to Microsoft update and shut it all down ! hence stop printing ! Easy when you know why ! So back to making my casting forms for motorcycle frame Im replicating from the 20s. Thanks again Harry

Thank you again Dust !" Im back printing again ! Have a learned a lot from you and the tips and advice where top , all the best Harry

Ok Im back again! The printer stops moves over to the left or right sometimes straight on and start all over again ! And stops at 22mm height everytime,the object height is 50mm when if ever it gets there !! And then stops and starts to build another 22mm high object ! Any ideas please !

Ok sorted my own problem ! Its a Windows 10 thing ! Cant go on internet when Im printing !!