The original Maytag Neptune series (2000-5500) was the most pretested machine Maytag ever manufactured.  However, it can have a couple of problems that have been there from the beginning.  Most of these problems were caused by that fact that Maytag did not design a line filter for the AC as it comes into the machine.

So; what are the problems?  No spin, timer runs continously, tub won't tumble, only cold (or only hot) water, no water, or water runs continously. 

One other poblem, very simple solution: Sometimes the "option" switches stick half way, always start troubleshooting from a known good position...that is, First reset you option switches and then set for cotton/colored/max extract etc.

No spin can be caused by Q6 failure, one phase of the motor windings is open/shorted, one of the three out of balance switches open, or your pump my be plugged,.

Q6 failure:  Normally the indication is no spin, R11 on the main control board burned.  Your wax motor may, or may not be bad, however, the new black shaft wax motor is a much improved part, if the SHAFT of your wax motor is brown or orange, replacing it with a new style black shaft unit is very highly recommended.  One caution, the copper on this board is very very light!!! use great caution if you solder on this board!!!!!

Motor phase failure:  On the large sheet of paper that should be tucked behind the pressure switch (behind the consol face) there is a section entitled "drive system diagnostics"  Follow the first procedure, if the tub does not tumble while executing the first test, your motor has failed.  If your machine is less than 10 years old, you should be able to obtain a new one under warrantee from Maytag CS, (Their 800# is on my Maytag web page) the PN is 12002039 it is called a "Motor Kit" and replaces your old motor and controller with a newly designed version, that has an input line filter!!!supprise supprise.  Much better part!   (There is a 10 year warrantee on the original motor)

Timer runs continously:  This timer is supposed to stop and start as directed by the micro (U1)  It should not run continously.  Q3 is the control triac, R52 is the feedback resistor.  Look to see if R52 on the main board is burned (not always) for this problem. (BTW: this timer very rarely fails.)

Tub won't tumble:  see motor phase failure, except this time the fuse on the motor controller has blown.  Don't bother replacing the fuse, it will only blow again.   Same correction, obtain a motor kit from Maytag (if your machine is less that 10 years old) or purchase Motor kit, Maytag PN 12002039.

Only cold (or hot) water:  Check your hose screens, if plugged, clean them, then if you still have the problem Remove the board and look on the back between the bottom edge and where the pins poke through, do you see burned traces?  Yes, you need a new board, or you need to transfer your good U1 to a core with good traces. I do not recommend jumping these traces, the possibility of more water than you want is too great!  No burned traces, triac Q9 controls the Cold water, triac Q17 controls the Hot water.  (BTW, these valves themselves very very rarely fail.  Only if you have very very hard water!)

Water runs continously: Almost exclusively burned traces on the back of the board between the bottom edge and where the pins poke through. (or again, very very hard water.  If you can unplug the machine and the water stops, the problem is NOT the valves)

Out-of-balance, strut problem, plugged pump etc:  There is a link to a free on-line service manual for the 3000 on my Maytag web page, down load it and follow the directions contained in it for these problems.

There are other problems that effect the operation, just email me if I haven't covered yours.  I would be happy to answer your questions.