Wa48j7770ap/A2 or wa52j8700ap/a2

[GaryBarbour]

It all starts with a wa48j7770ap that would not spin. The story I got was that the machine never worked from the time it was brand new. I did not really believe the story, but since I can fix just about anything, I figured it was worth buying for $80 since I needed an upgrade. 

 

As I dug into the project, my first clue was a pc code, indicating the position of the clutch was incorrect. I replaced the clutch motor. It did not work. 

 

More testing led to a pc1, indicating that the position of the clutch was unknown based on the feedback from the hall sensors. So I replaced the hall sensors. That did not work. 

 

My next conclusion was that the control board was bad, so I had my GF order one. This is where the wa52j8700ap comes into play. She accidentally ordered that control board instead. Being that all connections are the same I figured the only thing different between the two was a different size drum and a heating element, so at the very least I could get the machine to run. That did not work. 

 

Keep in mind that the machine is leveled and calibration is complete. 

 

My next step was drastic. I got a whole 52 series motor and drum assembly, brand new. Everything from the 4 drum hangers, thermistor, motor, clutch, hall sensors, and everything attached to the drum, with the exception of the aqua jet pump. Now I'm basically a few pieces of wire away from a full upgrade to the wa52j8700ap, all I have to do is wire in the heating element and jump the pcb heater board to the main control board. That did not work. 

 

I put my original wa48j7770ap control board back on the new 52 series bottom end. That did not work. It is still throwing a pc1 code. 

 

I used an oscilloscope to check the output of both hall sensors with the 48 and 52 series drum/motor assemblies. Both latched with a clean signal. The latched voltage was about 1.2V while attached to the main board and at least 3x that much when the hall output wire was disconnected from the main board and unloaded. I can't remember if it was 3+V or closer to 5V.

 

My conclusion is that the wa48j7770ap control board was always the problem and my wa52j8700ap is also bad. But the person who sold me the wa52j8700ap control board claims that it came off of a brand new floor model machine and therefore it absolutely is good. 

 

I replaced the heater PCB. That did not work. 

 

At this point I pulled the wiring harness and tested ever wire for opens and shorts to every other wire in the harness. The only inconsistencies I could find with the wa48j7770ap service manual is a clutch hall sensor which is separate from the two main hall sensors and two  missing spliced connections between the gnd and +5V from the main hall sensors to this elusive clutch hall sensor that doesn't appear to exist. I was thinking maybe it was incorporated into the heater pcb (dc92-00544a), since that's where the wires for it go, and maybe just adding the two missing splices would be the solution. I actually went as far as splicing them in, but did not install it yet because even though it supports the story about the machine never working from when it was new, it doesn't sit well with me that Samsung would just forget to splice some wires and send a machine out that wasn't tested. 

 

I should also note that someone was inside the machine before I was, indicated by alot of pry marks and evidence of disassembly and a service sticker on the back of the unit.

 

One resource addresses a PE and PE1 code (instead of PC and PC1), and the descriptions seem to indicate that they are the same codes. According to that source, the PE1 code is set when the motor "shakes" 15 times and is unsuccessful in detecting an appropriate hall position signal. This seems to be exactly what the machine is doing, as it jumps back and forth in small pulses but never spools up to full rotation. Alot of this happens with only the agitator as the control board tries to figure out what is going on with the motor. 

 

The wa52j8700ap board does not throw any specific codes, it simply doesn't stop cycling the "shake" back and forth to determine if the hall sensor signal is appropriate. 

 

At this point I want to finish the conversion to the wa52j8700ap model. The only things missing as far as I can tell are the wires to the heating element itself and the 3 conductor pigtail from the main board to the heater pcb that are labeled as heater control wires according to the wa48j7770ap service manual. I don't expect that this missing wiring would prevent the motor from spinning, but I could be wrong and will probably wire it all up tomorrow. 

I know this is alot of information, but I'm grateful for any assistance you can provide! Even the wa52j8700ap service manual, if nothing else, would give me some more insight!

 

I also have no problem sending you a couple of dollars for your troubles if you can get me to the solution I may seeking.