MAH4000AWW Water inlet valve is pulsing in final spin cycle

[wtfisthisjamf]

This is painful...

01: Replaced outer tub assembly because bearings were shot
02: Had to have a Maytag Tech come out because of a mismatch related to the Spinner support and the outer tub bearings
03: He resolved issue and reassembled the machine
04: Motor made really nasty noise
05: He advised me to purchase a 12002039 motor conversion kit and install it
06: Upon installation and machine power up, the AC filter that came with the kit hummed so loud I thought it was going to explode
07: Plugged washing machine into an industrial AC line conditioner and bypassed the AC filter
08: Plugged Neutral and Hot directly into the new motor control board
09: Hum gone, machine seems to work great until it hits the final spin cycle
10: Just as the timer control is activating the final spin cycle, I noticed a slight arcing noise that lasted about .3 seconds
11: Tub started to spin normally but, the two solenoids on the water inlet valve assembly (the ones that control the water input) started pulsing every 1-3 seconds throughout the entire final spin cycle
12: I let it finish even though the valves we spurting water into the tub
13: Cycle finished but no all the water drained
14:The distributor sent me a replacement 12002039 and all I want to do is to run some tests before I install the replacement kit to ensure that there's not something else wrong that has the potential the nuke the new-new replacement kit
15: Maytag "the company" won't allow me to talk to an engineer because of "liability issues"

I have 40+ years of electrical, electronic, mechanical and adaptive problem solving experience.
This can be fixed and if Maytag would send me a full blown schematic, I'd easily identify the problem and resolve the issue

Any ideas?

PS - sorry about the lengthy post, I used to do technical documentation for a living

[JWWebster]

They put that ac filter in there to protect the ICs in the board. Using an unprescribed line filter might not gel with their engineering.  What ya thank?

[wtfisthisjamf]

JW,

I understand what you're saying and totally agree. The reason that I put the entire washer on an industrial AC line conditioner was because I know when you hear a hum that loud on a filter, the capacitor circuit is nuked.

My concern is that because the AC filter was defective, it passed on "bad energy" to at least the new motor control board. Not having the full schematic, I can't say that it's only the motor control board that got nuked. Additionally, I followed wiring here and there, ensured that all the ground wires were solid, etc.

And speaking of ground wires, I laughed when during the read of the instruction manual that emphatically stated that the green ground wire from the main wiring harness MUST be connected to a specific point on the motor control board, and then discovered that the ground terminal on the motor control board does absolutely nothing.

Thinking I may be drunk, I checked both of the motor control boards that came with the 12002039 motor conversion kit and the original motor control board, all had the mysterious "ground to nothing" terminal.



Part # 12002039 Motor - Drve, AP4010145





The AC line conditioner that I substituted for the lame one on the kit can handle over 10KW, plenty to spare with the washer attached.

I come from the generation where a "board replacement" simply didn't exist. You pulled out a schematic, used the applicable test equipment to troubleshoot the problem, then replaced the bad components. I must say that dealing with "today's brand" of technicians is maddening.

[Repair-man]

If you have not replaced the door lock wax motor yet, and it has a red shaft on it, replace it. The arcing sound may have something to do with the machine controll board up top being shorted out due to this wax motor. The machine control also causes the water valves to energize, hence the reason I think you may have board issues. If you  remove the 2 nuts holding the machine control onto the  back plate, you might notice some  scorch marks on the green circuit gris along the lower edge. This will confirm a  bad board. A "complete" wiring schematic and technical diagnostic sheet is located in the top console behind the water level switch. I was with Maytag when this machine was conceived, developed and placed into the field in 1997, so I have a little knowoledge of its  iniquities. Too bad you invested all that money replacing the  tub, motor etc into an obsolete machine, but that is certainly your your option to do so...

[JWWebster]

Wax Motor 101

[wtfisthisjamf]

JW,

Oops, forgot to mention a few things I did already...
Here are the items I replaced:
(I didn't shotgun the repair, I figured as long as I had gutted it, why not replace them)
Water inlet valve assembly (it was letting a small amount of water into the tub overnight)
All the hoses
Everything in the door latch assembly including the wax motor
Outer tub
Bearing seals
Motor conversion kit and its replacement on deck when the determination as to whether or not the top circuit board is bad

I **carefully** removed the cover on the timer and inspected all the bazillion contacts and found no evidence of scorching
I did however inspect the wheels insofar as I could see without moving any of them
I also removed the top circuit board and inspected it under an 50x magnifying glass;
I looked at every single component for any signs of damage, including bulging capacitors
I did the same with the bottom side of the board to see if there were any burnt traces, cold solder joints, etc. Amazingly, the board looks like it just came out of the bag from the factory

This has definitely been an exercise in "character building" as an old boss of mine used to tell me
I'm at a point were I will fix it, it will absolutely not get the best of me.

I fixed my first dryer when I was twelve. Not bragging at all, just pointing out that I love to repair things and have the patience of a sniper

[JWWebster]

Jimbo (repair-man) is the expert on these wonders. I did have a page with photos of the suspect resisters that fail for these bad boys and one of them had to do with the water valve. But maytag had shut off them links. You would have to be an idiot to buy any maytag stuff nowadays. my opinion

[wtfisthisjamf]

JW,

Oorah!!! Here's what I did to fix the problem:
On the replacement motor conversion kit, I tested the AC line filter by hooking up a lamp cord with a switch a the .250" tab connectors. I put my meter on the other side and powered it up; no hum and the voltage on the output was clean.

Before I got too excited...
I pulled the top control board out and noticed that someone had taken a blue sharpie to a number of major current solder joints along with the entire row of the connectors. I re-soldered all them, put it all back together and it now works.

I really appreciate you talking with me. I know I make people crazy because I'm so anal and meticulous. If you don't believe me, ask my wife 

[JWWebster]

Wow that is cool. Glad you could git er done!! LOL

[niobrara]

Wow great job.