[Shelby5041]

hi i have a labvolt 5600 cnc machine

initial issue was when jogging z there was no movement at all...dead

prior to this the z axis motor and z axis worjked fine no issues

i have done extensive troubleshooting and after several swapping and proving out...i have come to the conclusion that its a bad z chopper drive board

there are 2 critical componenets on the chopper drive board L297 and L298 chips and i was told that the 1 or both of these could be the problem so i ordered both

as a start today i installed the L298 chip which is basically supplies power to the motor...i did not install the L297

well good news bad news...replaced the L298 chip on the labvolt
chopper drive and now it seems i have power to the z motor ..when i
jog up or down the motor is trying to turn however its grinding and
sounds like both directions fighting each other at same time? and not moving much at all....but the motor is attempting to move on command

if i take the x cable and plug into the fixed z board now the x motor
sounds like **** and wont move like its locked up...and if i put x
back to normal it runs fine

so it seems something else is going on although i do have power to the
z mortor now and i didnt have power before...it was dead when trying
to jog

any ideas? defective new chip? or maybe l297 part of issue?

the z axis is fine not bound up..can move easily by hand when machine off and just moving belt by hand...up and down....

[Shelby5041]

i also double checked my soldering and do not see any pins or solders that may be bridged

[Fastest1]

What happens when you plug the Z stepper into the X drive? Run smooth?

[Shelby5041]

No...z stepper to x motor ....rough...sounds like both drection fighting each othet

QUOTE=Shelby5041;2345530]hi i have a labvolt 5600 cnc machine

initial issue was when jogging z there was no movement at all...dead

prior to this the z axis motor and z axis worjked fine no issues

i have done extensive troubleshooting and after several swapping and proving out...i have come to the conclusion that its a bad z chopper drive board

there are 2 critical componenets on the chopper drive board L297 and L298 chips and i was told that the 1 or both of these could be the problem so i ordered both

as a start today i installed the L298 chip which is basically supplies power to the motor...i did not install the L297

well good news bad news...replaced the L298 chip on the labvolt
chopper drive and now it seems i have power to the z motor ..when i
jog up or down the motor is trying to turn however its grinding and
sounds like both directions fighting each other at same time? and not moving much at all....but the motor is attempting to move on command

if i take the x cable and plug into the fixed z board now the x motor
sounds like **** and wont move like its locked up...and if i put x
back to normal it runs fine

so it seems something else is going on although i do have power to the
z mortor now and i didnt have power before...it was dead when trying
to jog

any ideas? defective new chip? or maybe l297 part of issue?

the z axis is fine not bound up..can move easily by hand when machine off and just moving belt by hand...up and down....[/QUOTE]

[Shelby5041]

Oh z stepper into x drive.....runs fine...ive already determined its a bad stepper drive....
Im just trying to figure out why its doing this after replacing the L298 chip

QUOTE=Fastest1;2345690]What happens when you plug the Z stepper into the X drive? Run smooth?[/QUOTE]

[Shelby5041]

see images....i may have found something..i found a broken trace going to the + input voltage pin on the driver board..i just soldered in a jumper wire and will see if that fixes the issue

not sure if thats the issue or not but it cant be a good thing to have a broken trace so we will see

it may have happened when i was replacing the L298 chip...although with a broken trace going to the + input V not sure how i would even get power to the stepper motors like i did...interesting....

[Shelby5041]

What happens when you plug the Z stepper into the X drive? Run smooth?

Yes smooth

[Fastest1]

Hoping the broken trace is the issue.

[Shelby5041]

hi with the help of someone outside of this thread who told me these baords are repairable quite easily as compared to the newer style boards, and lots of troubleshooting and a bit of common sense i was able to fix it

the initial issue was no power to stepper motor due to failed L298 chip......the secondary issue that occurred after i replaced the L298 could have been due to 1 or both of the following matters

1. damaged broken trace at + V input to the driver board (caused by me i believe during removal of the old L298..i decided to cut legs off instead of desoldering a double sided solder joint)
2. 1 suspect solder joint on the newly replaced L298 chip

i addressed both of those and installed the driver board today and now the z axis motor runs smooth and is working well again

the repair was pretty cheap as far as parts...only about $2..i bought the L298 on ebay
even though the L297 was not the issue i did replace it since it was cheap $2 also and it is an easy plugnplay component..no solder involved and i ordered the part previously just in case..

so if anyone ever has issues with these old labvolt d&m computing chopper drives you may want to consider repairing them ....new is not always better....much of old is repairable..most new is not and most new is just cheap made chinese junk..thats why i wanted to save the made in USA chopper drive...these older chopper drives are very difficult to find for sale and are very costly so saving it was a smart move i believe...and ii definitely prefer a made in USA item over a made in china item....although the new chip i bought is made in china lol...but hey that was not by choice...not much of any electronic items made in usa anymore.

[Fastest1]

Back to making chips! WooHoo