Called out earlier today on a Manitowoc QDO450 ,, No Ice.
I initially saw that they had switiched it over to clean before turning it off.. So I had to wait for that finsish up first, meantime I looked the unit over everything seemed fine.
Finally after clean cycle finished, it went into "Make" and I didnt notice it right away but the harvest red light was on. I noticed it after it went into harvest after 6 minutes,, (after reading the tech book, this is what it was supposed to do.) the six minutes not the red harvest light.
So then I started messing with the Ice thickness probe. the red light was on. I Acutally removed the probe from the evap and still on. , It only went off after I unpluged the probe wire from the control board.
Here is where it gets weird.
I put an aligator clip to the control board where the probe was pluged in.. Light off...
1. Touched the end to the water: Light on =okay
2.Touched to unit ground: Light on= okay
3. touched with my finger:, Light on= weird
4. touched to the completly isolataed and unistalled ice probe not touching any metal: Light on= Very Weird.
5. Touched to a Brand new Probe I had on truck still in plastic wrap. : Light on = very very weird.
oh yeah I even uplugged power thinking the board needed a reset. no differance.
There I was, just lost, and tech support was closed. So I just left it unplugged and let it make ice for a while till I felt it was time for a harvest. Bout 15 mins. I plugged the probe back in the light came on and it harvested.
then the very next cycle It was back to normal, and the four after that, so I just tip toed away. but I have the feeling that I will be back soon.
anybody have any tips or ideas. I told the owner my findings and if it goes out again just leave it alone till I get there. and perhaps I may find something like a flash code or something.
I appreciate any help guys.
Doesn't take much to ground the probes. the old probe probably had a buildup on it bridging between the adjustment screw and the wire. Unless you were wearing brand new boots and standing on a dry rubber surface it was going through you to ground.
The Clean cycle on a Q-Series machine can be canceled by switching to Ice and Off once or twice. This also overrides the six minute delay for the controller to look at the ice thickness probe. It's a service tool.
If the machine had shut down on a safety limit it would store the code and display it on switching from Off to Ice by flashes of the red Harvest LED.
The ice thickness probe itself is nothing more than piece of metal tied to a wire that plugs into the control board. The control board doesn't look for a connection or short to ground......rather it sets up an RC circuit (resistance/capacitance) circuit and just touching the probe will change the capacitance of the circuit enough to light the LED. I'm not fluent in electronics, but that's how it was explained by the Manitowoc service rep.
Get yourself a copy of the Manitowoc service handbook at the distributor or download it at http://www.manitowocice.com in the service support section.
Did you ever try putting the new probe on?
A Diamond is just a piece of coal, that made good under pressure!
I had the exact problem about 3 months ago on same
machine,sold new circuit board, installed and same
problem,checked wiring for loose connections, then
problem just disappeared, machine been working normal
ever since,tech support guy insisted it was ice thickness
probe causing problem but i installed brand new probe
first and same problem.
I did not know that you could terminate the Clean Cycle, I will have to try it, instead of standing there like a dummy. Also, Thanks for the other tips, That makes sense about the boards resistance circuit. I do have the little orange/yellow service book. That's where I read about grounding a jumper, guess it kinda threw me off. But what I could not find in the book was flash codes.... But wait.. I will bet they are on the back of the cover.. I didn't even look at that. duh. Btw, I have read lots of your posts in the past and you really seem to know your stuff! I hope to reach Guru status too someday with ice machines.
Cynic & Frozensolid:
The old Ice probe was good to go. I installed it last summer when I picked up this account. The old one was cracked at the hinge, and the machine was very very calcified. I cleaned it real good and installed a good water filter system. so it stays pretty clean now.
Its frustrating huh? I will let you all know what I find when/if they call back for it. I just called and the machine is still working now, so it may be a while before I go back.
Hate to say it but I have had two brand new start-ups with board/wiring problems..
One a CVD with a QY1400 head, board 9 pin connections bad.
Now a SD450 unit, same problem you talked about CoolCopperUSMC.
Thats not normal for Manies.... I hope..
What is snow? Is it that white stuff in a freezer?
I do a lot more service than I do startups, but on Manitowocs I have to say that I have never in recent memory had a serious startup problem. I just set 'em up and they run.......and they rarely need any adjustments at all.
In-warranty stuff is a whole 'nother story.
Their control boards are solid. I can't remember the last time I had to change one out. I just wish they would put those boards in a better made machine with an evaporator that will last longer than five years.
Yuma.....it is normal for Manitowocs to be real sensitive to that ice thickness probe being fouled with a little mineral scale or even moisture.
Keep a hair drier or heat gun handy to dry off those probes if you're working Manitowocs. I used to use Ms Icemeister's Lady Clairol quite effectively........but the Milwaukee heat gun is more appropriate.
What is snow? Is it that white stuff in a freezer?
Bet you had a error code #2. Harvest time exceeded 3.5 min.3x. Unplug ice thicness probe from board. If light goes out, board probably ok. If light stays on, chuck the board. If unit is in a manual clean mode, put switch back to ice and let clean mode time out. unit will then go back into a freeze mode. Or you can just terminate clean mode by shutting unit off. The board has to see a certain resistance in order to go into harvest.
Because ice thickness probe and water level probe use DC current it is very important to make sure the ice machine is properly grounded and the electrical supply is also properly grounded