LT 40 electrical

[autotomk]

having an apparent wired issue with up down system.  it is now dead in the water   checked motor it runs good with neg  pos power to the two terminals  not sure if that is correct way to check but it does work??  so checked diagnose lights on accuset 2 all good according to book check, and on alarms.   motor has power to both legs when push down on drum switch but no movement,  up on switch no power no movement.  not sure also if that is correct way to check power at motor?,  im using 12 volt light  one end grounded  other on each leg.  woodmizer said driver modual after shot conversation with him (im not real confident in diagnoses  he is not either) want me to check for other modal in accuset box when I get a chance   driver modual is 650. ouch  hoping it was the spark plug.  any ideas???  hope this is some what clear

[autotomk]

Found the problem with the help of woodmizer   a broken wire in the harness right above the up down motor .  Those wires move every time you engage the blade .  A 12 gauge strand  wire, no aparant reason to break??? Must have been the moment since 2002 when mill was built.  First time I found a strand wire that size break.  Seen solid break not strand though.   So heads up it does happen!!! 

[Magicman]

Sounds like it was a manufacturing defect of the wire itself.  Anyway, yours is another example of sticking with the WM service technicians.  :P Those guys are masters of their field. 

[3Dog]

I just had the same thing last week. It's not the first time I have had the issue. It would work, then not.  Sometimes after turning a large cant or bumping the drum switch  it would quit. I have placed a number of calls to tech support for the issue and have gotten several suggestions from brushes need to be changed to a bad computer module (changed that already as well).  After HOURS of time on multiple occasions with a Fluke meter I found that the post on the up down motor, that has rubber or similar material insulator that has a slight amount of play. What's found was that the original brushes my mill came with had a circle terminal. When I order new brushes they came with a  "U" shaped terminal. The tips of the terminal stood out just  enough past the mounting screw that if the rubber  terminal isolator was jarred or wiggled the terminal would touch the motor case and short out and cause a complete up down failure. I changed the terminal and so far it has worked flawlessly.

Excuse poor typing due to trying to hit tiny letters on my """Smart""" phone without the benefit of my cheater glasses....over my bifocals which I wear even  after surviving Lasic surgery.

I'm not a fan of getting older.

[autotomk]

Mine is a 2002 also 3dog  only a standard hydralic.  I'll have to watch for that brush problem when I need to replace.    Woodmizer has always done me right

[Colonel_O]

I'm looking at old threads regarding up/down issues on my LT40.  Was sawing today and 4 hours into it, the saw head would not go up.  It goes down OK.  I let things cool off hoping that might help.  It didn't.  Troubleshooting, I switched the up wire with the down wire, and the saw went up that way (it would not go down however).  

I checked the drum switch, but other than verifying that its making contact and adding grease, I'm not really sure what else to look for?  I'll call Woodmizer on Monday and live close enough to Marty to take it there if needed, but wondering if anyone has any ideas?  

[ellmoe]

Same problem. As I just read at the start of the thread, we went through several possibilities. The wires were broken where they come out of the harness next to the drive belt. Enough threads were intact to allowed a 12 volt meter to show voltage, but not enough amps to move the motor. At first is only happened when clutch was engaged ( created enough wire separation that motor would not work, release clutch and wires connected ). Something to check, anyhow.
Mark

[pineywoods]

setworks ? If so, smells like H bridge.  No setworks, broken finger on drum switch..

[Colonel_O]

Thanks—I'll double check wires.

[Colonel_O]

I do have setworks.  Not sure what an H Bridge is?

[pineywoods]

H bridge is the setworks electronics module that controls the up/down motor. Contains, among other things, 4 big power transistors, 2 for up, 2 for down. Located in the add-on box on top of the control console. On mills with no setworks, the drum switch controls the up/down motor directly with maybe a relay or circuit breaker. Obtain a 12 volt test light or voltmeter, and call woodmizer, sparks will walk you through a test procedure. (but not on a weekend) :

[Colonel_O]

Thanks very much.  These things always happen to me when I'm alone and unafraid on a weekend.  I'm sure I'll get great help on Monday but really appreciate the feedback to get me going.  This forum is great!!