Now it's 2010 and it just had its first failure. It won't run the spin cycle after each wash or rinse.
The internet came to the rescue with great information on trouble shooting and a free download of the service manual. Check out Appliance Aid. Google took me straight to their Neptune page
Number 9 was my problem - no spin. The page told me exactly what was wrong and how to fix it. It also contained a link to Roy Goetjen who's done failure analysis on the circuit board and determined how to keep it from failing again.
His page has even more detail on repairing the control board and offers a repair service that's fast and very reasonable.
Roy's Neptune page.
If you can use a screwdriver without hurting yourself, you can open your Neptune, remove the control board and send it to Roy. He also has replacement wax motors - the weird device that locks the door when you start the washer. Get one of those from him too, or you can get one from from Appliance Aid if you're fixing the board yourself. Either way, replace the wax motor, even if yours appears to be OK at the moment.
I chose to send my board to Roy because by the time I ordered the parts I'd need from Digikey (with minimum order quantities) and order the wax motor from Appliance Aid or Roy, I could get the board to Roy and back - fixed. So I took the lazy way out and sent it to him. In the days when I had access to a vacuum desoldering station, and could do board level repairs on 4 layer circuit boards with no problem I would have done it myself. Guess I'm getting old.
My circuit board with R11 fried to toast.
Components needing replacement:
R11 - triac gate pull up
Q6 - door lock triac
Q2 - triac driver
Probably should check R60 and R78 as well - emitter and collector resistor respectively
Roy determined that the factory triac isn't robust enough and eventually fails, taking R11 with it and sometimes the wax motor too. The original is rated 400 V, 800 mA. He's using a replacement that's rated at 600 V and higher current for better longevity.
I've done current measurements on the operating wax motor and agree completely with Roy that the triac needs to be heftier. My Fluke DVM shows a startup current of around 250 mA. Mind you a digital meter can't show a 1 cycle inrush at all, so I'd guess the actual reading is several Amps. The part is rated for a 1 cycle inrush of 8 Amps, but I'm betting that several thousand activations of the wax motor eventually current-spikes the triac to death. Needs a beefier part. Roy's part is rated about 20% higher for inrush, which will probably double the life of the part.
In addition to all the above, Roy has also determined that the wax motor itself can be a source of triac damage. Its construction is such that internal corrosion can eventually result in poor contact at the heating element connections, which can cause major voltage spikes - killing the triac. It shorts from MT2 to the Gate which sends full current through R11 - instant toast. This is the main reason for replacing the wax motor even if your existing one seems to work OK. The new part is internally sealed, which minimizes the internal corrosion problem, thus giving longer triac life.
So, meanwhile, how do I get my laundry done? I scoped out the circuit and rigged a bypass to make the wax motor lock the door so the machine would spin. I finished all the laundry and then pulled the circuit board to send to Roy. Here's the bypass - use at your own risk - that's 120V AC you're looking at there. It's a big, hi res picture so you can download it and blow it up for detail. Obviously, you don't need the meter in there to run the machine. I just left it there after taking current readings. You could just put a switch in place of the meter and turn the door lock on and off as needed. Just be sure to insulate everything - it's 120V AC!
If you're the electronics geek type, here's a scribbled schematic of the door lock part of the circuit.
And here are most of those parts shown on the foil side of the circuit board.
