RAMPS 1.4 Woes !!! Need a Hail Mary pls !!!!

hi,

i had bought a complete ramps kit from gadgets3d ... and i have mailed them quite a few times .. and still no response ...

Ramps 1.4 and everything worked fine for a couple of months etc, till my modified atx psu shorted and then i stripped the machine to add a couple of upgrades ... i decided to move from 5 mm z axis rods to 8 mm .. add belt tensioning facilties, cork sheet for insulation to the bottom of the heated, so printed out parts etc and reassembled everything ... also i wanted to change the A4988 to DRV8825 for all axis ... but waited till the system was working fine

then i freshly installed marlin the latest version, following your pdf manual from the site, for the components selection and steps etc ...

Problem 1 :

i got the motors to move a couple of times, through Repetier host (RH) 0.95f and the latest 1.0 ... the manual controls the motor did not move ... only when the 3 home buttons moved ... after homing also they would not move ... using the 10, 50 100 buttons in the manual controls ...


Problem 2 :

The axis had a problem with the new rods and upgrades ... so i rectified that and greased it etc ... now it turns without any effort by hand ...there was a slight alignment issue and i had added bearing on the top to keep it aligned ... i use 5 ---> 8 mmm flexible couplings ... but still using Reptier Host or even simplyfy3D i could not move it ...


Problem 3:

so i had gotten another ATX power supply 600 watts, and pulled 4 leads from the PSU, using 12awg for the 11A and 14awg for the 5A connections ... Repetier host connects etc .. but still no manual control and neither does the heatbed light come on .. so to check if the heatbed works, i pulled the D8 wire out and just held it for a second or so, on the 11A connections .. the lights on the led came on ... and in RH, when i press the heat the heatbed option there is no light, .. so i checked the D8 connections with a voltmeter and now power is coming to the D8 connection


Problem 4:

I had been using a Jhead till now ... so i decided since i have stripped most of the machine, i decided to change the thermistor on it .. so i soldered the thermistor and resistor again and checked continuity from the board, it was fine ... but in RH when i ask the hotend to heat up it automatically switches off in a couple of seconds ..i dont know why ?


Problem 5:

I even connected a volt and amp meter, as per the diagram attached, where the load leads are taken from the black wires of 11A and 5, through a Y cable ... but i see no amp draw whatsoever ...

Things i have done, to try and trouble shoot :

1. Pulled out the ramps board separately, and without any input power inpout to it, i check the ptc fuses for continuity,,, it was fine ... then i checked all 3 mosfets, based on a youtube video, using diode/continuity option on the multimeter .. i got a reading only from the drain (black lead from MM) & source (red lead from MM) .. and i got a reading around 520+ for all 3 mosfets ... so i think they are fine ...

2. Pulled out the arduino mega and cleared the eeprom, and then reflashed the marlin, it compiled and uploaded perfectly ... and still no movement or no heating of either the heat bed or hotend ...

i have attached pics of the heatbed and the way it is connected, both front and back ... pls take a look .. previously i had a problem of the heatbed goning more then 80 degrees ... as i read in the forums to check the resistance ... i used my multimeter, without power to the heatbed, with the 200 ohm option on the MM, on the new MM i got a reading of about 2.1 - 2.4 and on an older MM i got about 1.6 - 1.8 ...

i used these 2 millimeters to check the fuses and mosfets as well and got exactly the same results for the fuses and mosfets .... but for the heated bed resistance test i got 2 diff values ...

so based on these MM tests i think the ramps board is fine ?? pls let me know your comments

so basically i am stumped, and read up on many forums ... i was adviced not use 4 leads to the ramps board, but power only the 11A from the PSU


Other suspected observations :

1. i have not connected all the endstop switches, although they are active in the firmware ... is that a problem ...

2. when i as upgrading the mechanical parts etc, i noticed the ramps board (picture attached) had 2 pin touching each other ... hope this has not caused a problem ...

i have been trying everything i could, i even ordered the galss & blade fuses, so i can remove the ptc fuses on the board, close the circuit with 14 awg of 16 awg wire and use external auto/glass fuses of 5A & 10A on the power leads coming to the ramps board rom the PSU .... i will get that in a day or 2 ... should i make that change to the board ??

also i have an SMPS based 12V 30A power supply also on the way ... but its funny i had used 450 watt modified atx psu intitally and it worked and ran round the clock.. even this new modified psu 600 watts, shoes 12v output on the MM ... also earlier, i was cooling the ramps board continuously, with two 90 mm fans .... it used to run for 16 - 30 easily without any issues

sorry about this and the long mail .. but i just cant move and i have tried to no avail

any help/advice/direction would really help me a lot ..

eagerly and desperately awaiting for any reply/direction

thanks

chX

Quote
crazyhorseX
... i was adviced not use 4 leads to the ramps board, but power only the 11A from the PSU

Does this mean you do not have power to the 5 Amp rail? If so, then that's completely wrong. The 11 Amp rail powers the heated bed and nothing else. All other components - hot ends, stepper motors, etc, are powered via the 5 amp rail. If you do not have power connected to the 5 amp connector, your motors will never move.

If your endstops are configured as normally closed then you won't get any movement in the motors without the endstops connected. They're done this way to prevent damage if the endstop wiring comes loose.

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