Fisher & Paykel; Motor Control Board

[mrfix]

Reivax,

I measured 78.5Khz on my friend's working board, mine was 81.2Khz. I then changed the feedback resistor in the Osc circutry to bring it down to 78.5. This allowed the machine to start a cycle. What is strange is that when I blow into both sensors they seem to respond the same way but mine still has a problem. Where do you get these sensors from .....does anyone know the manufactururer ?

I emptied the wash bowl before I attached the tube again, I'll try changing the capacitor value........has anyone tried this before under the sensor ?

Cheers
Con

[rievax]

Reivax,

I measured 78.5Khz on my friend's working board, mine was 81.2Khz. I then changed the feedback resistor in the Osc circutry to bring it down to 78.5. This allowed the machine to start a cycle. What is strange is that when I blow into both sensors they seem to respond the same way but mine still has a problem. Where do you get these sensors from .....does anyone know the manufactururer ?

I emptied the wash bowl before I attached the tube again, I'll try changing the capacitor value........has anyone tried this before under the sensor ?

Cheers
Con

I have been able to repair some by first removing the old capacitor from the underside of the sensor, its covered by black sealant. The trick is to find a capacitor that is slightly lower than the correct final value and pad it with smaller ones to get the frequency right. Also best to restore your osc circuit to it original state.
How are you powering your PCB for testing?

[rievax]

Just remembered another fault I have seen. There is a 150 ohm resistor in seriers with a cap connecting to the outside corner pin of the sensor. The cap can go leaky causing the osc amplitude to fluctuate and to sometimes stop.

[mrfix]

Powering the board with a 12-15 V dc supply and one of the diode ends removed so power doesnt go back into a device I have been unable to identify, 3 legged device....looks like a fet of sorts but I suspect it forms part of the switchmode circutry . Anyway, 13 V dc going into 7805 which then powers Micro and display etc.

The cap you mentioned in series with the 150ohm resistor measures 404nF out of circuit. Not sure what value this is supposed to be .....any ideas ?

Cheers.

[rievax]

Powering the board with a 12-15 V dc supply and one of the diode ends removed so power doesnt go back into a device I have been unable to identify, 3 legged device....looks like a fet of sorts but I suspect it forms part of the switchmode circutry . Anyway, 13 V dc going into 7805 which then powers Micro and display etc.

The cap you mentioned in series with the 150ohm resistor measures 404nF out of circuit. Not sure what value this is supposed to be .....any ideas ?

Cheers.

I have never bothered measuring the cap in series with the resistor. Its a coupling cap and doesnt affect the frequncy. I used to replace it with a 1uf monolithic.
I apply 15v to the cathode of D241, no need to remove the other end. 13v is ok.
All motors current dump into the 15v rail. That mosfet is turned on when the rail gets too high and diverts motor current to 0V until the rail drops below 15v again.

[mrfix]

Rievax,

Thanks for that info, I'm going to replace the 10nF under the sensor as a starting point and see if that makes a difference.

Fingers crossed.

[marineman]

Greetings, just asking if anyone has a Phase 5 / Gray Motor Controll Board so i can find out details of a damaged FET in a Pride 5.5 Washer i have.
Fuse F124 has gone open & a FET(?) on opposite side of PCB & close to R663 (0.125ohm/2W) has a piece missing so i cannot read all numbers.
Appreciate any replies re this component.

[rievax]

I see it as 75309. I have used IRFZ44L which is tricky to fit because of its larger size but works fine.
There will be much more wrong with that motor controller.

[marineman]

Hi Rievax, thanks for reply, i read these phase 5 controllers were the worst ones made by F&P. Will try changing a few FET's & double check the loads for the psu.
Cheers,
JEBL

[rievax]

Problems usually are caused by intertrack leakage caused by condensation. This leads to usually the pump bridge IGBTs partly turning on, overheating, then going short. The original fuses dont adequately limit fault current and duration. The mains bridge doides and D241 are often also damaged.
The condensation can also create permanent leakage under some of the small surface mount transistors which will cause IGBTs to fail again.
And many more possible problems.

[marineman]

Thanks again Rievax, i can see some of the pump FETS show signs of sunburn on pcb! Appreciate your advise, but it sounds like maybe too many probs. I shud stick to Radars.
Cheers,
JEBL

[mrfix]

Hi Reievax,

I'm back again, unfortunately my pressure sensor is playing up still . I soldered multiple caps on the sensor as you said to get it to the right freq but same problem in that the sensor doesnt change freq correctly when pump empties water. It almost seems like there is corossion or something stopping the diaphram from moving rod through the coil at the correct rate. Anyway, given up on repairing that sensor. I was wondering if anyone on here has a spare pressure sensor that they are happy to sell ??????

[rievax]

The sensor can be easily taken apart by releasing the 4 tabs. Just need to be careful to put the white spacer back in the same way. Its between the ferrite slug and the spring under the diaphram. There are vent holes in the lower housing, I guess something could have got inside.
Does the machine roughly fill to the correct levels?
Have you tried disconnecting the pressure tube while its pumping down?

[mrfix]

Hi Rievax,

I took the plastic lid off but saw a rubber diaphram, didnt want to go further. Looked like the black rubber was sealed to the nylon wall of the housing but I guess this can be lifted out?
The machine does fill correctly. It's only when pumping water out that I have problems. I havent removed the pressure tube while pumping down. I guess that will simulate falling water level prompting the machine to go to spin ?

[rievax]

Yes, the diaphram edge sits in a groove and rolls out easily. Also check that you can blow through the tube easily.

Its just occured to me that you might not be sure that the frequency isnt changing during pump down because the frequency isnt safe to measure while the motor controller is fitted to the machine because all circuitry becomes live.
What do you actually notice during pump down? Does the machine eventually report a fault code?

Edit: I see you mentioned code 39 earlier.

[mrfix]

Yes, the washing machine pumps out water ....continues to pump out water for many minutes then error code comes up saying pressure sensor failed to make a change within x amount of time. Cant remember specific fault code though. I'm going to open the sensor and see if there is any corrosion or anything making the unit get stuck.

[rievax]

You could also try tapping it to make it unstick if it doesnt respond to the tube being disconnected after pump down.

[paulmac]

Hi Rievax (and all those reading)

I have a phase 5 (GW709) washer that has suffered the exact symptoms that have been described : F124 gone, the two pump IGBTs were short circuit, and the item you identified as 75309 is only a 753, due to a chunk of it missing! From what I can measure, all the rectifiers are ok.

Two possible plans of attack:
1: Repair the board. Should I order direct replacements for the IGBTs, at around $5 each from Farnell, or do you have suggestions for better/other parts/suppliers?

2: My mate has given me all the top bits for his GW712 Excellence Phase 6 (brown) washer. Would the modules drop-in and drive my older motor ok?


Paul

[rievax]

Hi Rievax (and all those reading)

I have a phase 5 (GW709) washer that has suffered the exact symptoms that have been described : F124 gone, the two pump IGBTs were short circuit, and the item you identified as 75309 is only a 753, due to a chunk of it missing! From what I can measure, all the rectifiers are ok.

Two possible plans of attack:
1: Repair the board. Should I order direct replacements for the IGBTs, at around $5 each from Farnell, or do you have suggestions for better/other parts/suppliers?

2: My mate has given me all the top bits for his GW712 Excellence Phase 6 (brown) washer. Would the modules drop-in and drive my older motor ok?


Paul

It would be a better option to fit the phase 6 parts but you will need to replace the whole upper deck assy because phase 6 machines have a lid lock solenoid instead of a lid switch.
About those IGBTs. All are the same type except for one in the pump bridge. Its p/n ends with a U insted of S. Does it look like condensation corrosion was the cause of the failure?

[paulmac]

Thanks for the reply.
There are traces of corrosion, where the lacquer appears to have come off a trace or two, but it's on the opposite corner of the board, ie as far away from the pump cct as you can get. I'd have to have a closer look tomorrow and trace the signal paths to see what they connect to. There are also dots of corrosion (I think) along the bottom edge of the board.

I picked the difference in the IGBTs. Thanks. Pity. The motor drive ones were $1.50 or so, and available in Aust too. I have to wait for the others (I figured I'd order them anyway...).

I'll get the top deck bits sent to me from the phase 6 machine. So that's all that's needed? All the plastic bits from the top?