FMQ2-36 Dead....Need new board?

[in_cognito]

Hi All,

18 months after installation my FMQ2-36 died. I checked the board and the low voltage fuse was busted. Replacing the fuse and turning on the power blows it again.

Disconnecting the load (compressor power, fan power etc.) from the board and turning on the power still blows the fuse.

The regional repair company has no ETA on when they can get my board replaced/repaired. Any ideas? Suggestions?

[cngryan]

Re: FMQ2-36 Dead....Need new board?

I know of a man who works on fuel makers and he infact replaced my FM4 fuel maker board and it was not cheep but its not done! his name is Smokey with Clean Air Technologies he can be reached at 1-503-254-8786 or by e-mail at [email protected]

Hope that helps!

[siai47]

Re: FMQ2-36 Dead....Need new board?

Look at the board in the area around the small transformer on the board. Try to follow the traces on the PC board to see where they go from the fuse. They should go right to the transformer. From there I think they go to a diode to rectifiy the AC to DC for powering the rest of the electronics. See if the board looks discolored around the diodes. A simple ohmmeter can test them (or the transformer) for shorts that would blow the fuse. If you are lucky, your problem might lie there. Your don't have much to lose if the board is fried and none are available.

[Amfuel]

Re: FMQ2-36 Dead....Need new board?

Fuel Maker is rebuilding boards. Check with a dealer near you and have him find out the inventory status.

[slctech]

Re: FMQ2-36 Dead....Need new board?

90% of the time when the .6A fuse blows, it is failure of the T282 Power MOS transistor. It will over-heat and short to ground internally. They were made by Motorola originally, motorola discontinued manufacturing them. SGS-Thomson picked up after that, then they stopped making them. We ended up finding and purchasing one of the last surplus inventory of ten thousand transistors last year.

I am finding that slow failure of the the R10 resistor is a main culprit with the transistors failure. We have upgraded that resistor to a higher wattage rating with huge success in our testing.

Also, when the transistor goes, it is either goes quietly with only the fuse blowing, or it goes with a bang taking out the R20 and R22 resistors. I usually see this more when one installs a higher amp fuse to try to remedy the actual .6A fuse from blowing.

In either case we repair boards or can send you out a repair kit with the transistor, upgraded R10 resister, R20 resistor, R22 resistor, F355 fuse, and replacement zip-ties to strap back down the ambient temperature sensor to the board mounts and the programming port back to the chasis.

[karl]

Re: FMQ2-36 Dead....Need new board?

Siai,
You sound like you know your way around a PC board pretty well.
My FM4 won't start currently and my hunch is that the motor starting capacitor is not being switched in as it attempts to start.
The motor hums and then blows the 15 amp slow blow fuse closest to the center of the board. I have tested the capacitors and they test out fine, I swapped them for alternate capacitors with no change in symptoms.
When I replace the fuse and try to start the compressor the motor hums and the large Siemens contactor that controls the motor starting capacitor buzzes loudly and if I take the cover off the contactor the contacts seem to vibrate as if the coil voltage is dropping as the motor tries to start.
I pulled the head off the tub and it spins freely, there is no signs of contact between the armature and the stator but after a few attempts to replace the fuse and restart the compressor the armature is too warm to keep my hand on it for a few seconds.

My best guess now is that the small relays soldered into the PC board are not switching as they should to engage the start or run capacitors. Before I pull the board out and send it off as an exchange for a remanufactured board I would like to do a little more diagnosis/troubleshooting.

Do you have any suggestions on how to test the relays on the board?

I cant read any description on the start and run capacitor relays but the relay that controls the fan capacitor is either identical or very similar to this one.
http://www.ebay.com/itm/5-x-JW1FSN-D...3D371046099094

The relays for the compressor capacitors are a little larger but similar. If I knew what make/model the relays were I could just try soldering in new ones. If I am considering this route I could also just de solder the existing from the board to read the info and bench test it off the board.

What would you suggest?

Thanks for any input.

Karl

Look at the board in the area around the small transformer on the board. Try to follow the traces on the PC board to see where they go from the fuse. They should go right to the transformer. From there I think they go to a diode to rectifiy the AC to DC for powering the rest of the electronics. See if the board looks discolored around the diodes. A simple ohmmeter can test them (or the transformer) for shorts that would blow the fuse. If you are lucky, your problem might lie there. Your don't have much to lose if the board is fried and none are available.

[Lakewood90712]

Re: FMQ2-36 Dead....Need new board?

Karl,

You might want to call these guys www.gocngpumps.com I believe they are ex fuelmaker employees with a small aftermarket parts and service business . I don't think they are an authorized dealer.

[siai47]

Re: FMQ2-36 Dead....Need new board?

Those boards are a pain. Most of my problems have been with fuse holder failures with the early style holders. Usually, if the board fails, not much happens. It does sound like you might still have a capacitor problem. Would it be possible to take them to a electric motor repair shop and have them checked? I had a pool pump motor that exhibited similar problems to your compressor. It wouldn't turn--just sat there and hummed. With the pool pump, it was easy to check the thing out by giving the impeller a spin by hand and the motor would start (a little hard to do with the fuelmaker). A new capacitor solved the problem. Also, when you had the module off, did you notice any discoloration in the windings of the motor stator? Sometimes a failure of one of the windings will give you the same problems you are seeing. Sorry I can't be of more help on this one.

[Amfuel]

Re: FMQ2-36 Dead....Need new board?

Check the control module with your ohm meter.

1 - 4 = 6.5 If 6.0 or below, replace stator
2 - 4 = 2.7
1 - 2 = 3.8
3 to 1, 2, or 4 no reading (ground)

I do have P30 electronics module and control modules in stock, new.

[John Mitton]

Re: FMQ2-36 Dead....Need new board?

I recently had to replace my FMQ-2-36 board. The guys at GoCNGpumps.com tried to do what they could but in the end a replacement board was the only option, and as posted above they don't have a direct relationship with Fuelmaker. It was just under $1k after shipping from www.CNGaz.com

If you replace your board, don't discard the little stick-on insert button extenders which will be needed to allow the new board Start and Stop buttons to be depressed once it is all packaged up.

[karl]

Re: FMQ2-36 Dead....Need new board?

Thank you to everyone for the helpful replies.

It is good to hear there are several options for replacing the board.

I am not convinced that it is the problem and would like to clearly identify the problem prior to throwing parts at it in hopes of getting it running.

Amfuel.
I am especially interested in what you posted. If I am interpreting it correctly the first numbers separated by a hyphen are terminal numbers for the stator windings and the numbers following the = sign is the reading I should get on my ohm meter as I measure across those terminals. If I check those three pairs and get numbers ten percent or more below what you wrote I should assume the stator has failed/shorted out internally.

If the stator has failed is that a bolt in winding assembly?

Thanks again,
Karl

Check the control module with your ohm meter.

1 - 4 = 6.5 If 6.0 or below, replace stator
2 - 4 = 2.7
1 - 2 = 3.8
3 to 1, 2, or 4 no reading (ground)

I do have P30 electronics module and control modules in stock, new.

[karl]

Re: FMQ2-36 Dead....Need new board?

Amfuel,
I think I am misinterpreting you.
I tested the resistance across the wiring loom that goes from the "tub"/stator to the brown 9 pin plug on the circuit board.
I got 14 ohms from the black to white wire (#1 to #2) All other combinations I got an open circuit.

Can you clarify the wire identification.
I get
1=black
2=white
3=gray
4=red
5=empty socket
6=orange
7=yellow
8=green
9=purple

Are the numbers you listed the reading I should get with an ohmmeter across the wires I am describing?

I pulled the head again and the stator windings look fine at casual glance. If I look really close with a flashlight I do see a a very faint light gray film on some small random sections of the winding that easily wipes off. Overall the varnished wire looks fine and undisturbed.

If you can give me a bit more info on testing the stator I would greatly appreciate it. If I can rule out the stator then I can feel confident spending money on pc board repair or replacement.

Thank you,
Karl

Check the control module with your ohm meter.

1 - 4 = 6.5 If 6.0 or below, replace stator
2 - 4 = 2.7
1 - 2 = 3.8
3 to 1, 2, or 4 no reading (ground)

I do have P30 electronics module and control modules in stock, new.

[Amfuel]

Re: FMQ2-36 Dead....Need new board?

It is the 4 pin connector to check branched off the main coming from the control module. The 9 pin connector is the other one.

1 - 4 (either end of the connector) should be 6.5 ohms. below that is showing a weak stator. 5.9 ohms and it surely won't run. Green is ground. (#3)

The stator can be replaced by a technician. Better to just start over with a new control module and be done with it especially if there is any suspect of a low voltage issue. The controls may be affected also.

If the EM has a burned fuse or scorch marks on a fuse it probably has been operating at a brown out (low voltage) condition and that will damage other parts either directly (now) or indirectly (in the near future)

Low voltage causes the parts to get hotter than designed for and damaging them. With full power reinstated, any damaged part will fail at some point. Today, tomorrow, next week, next month, 6 months from now. Low voltage can make hamburger out of an electric system. Repairing a board is chancy. Fix it to work only to have it last only a short time.

The new BRC Fuel Maker does not rebuild parts. New parts only. Rebuilding parts was the old Fuel Maker.

[karl]

Re: FMQ2-36 Dead....Need new board?

I have had some difficulty getting my ohmmeter to give me accurate enough results to test the stator windings so instead I wired up a separate circuit with a different run capacitor and a the original start capacitor. The motor starts and runs beautifully and the circuit board still seems to control the rest of the functions fine.

I am concluding that the relays that switch in the start or run capacitors are getting weak or the contacts are developing resistance. I should probably just get a reconditioned circuit board but I am still hoping to figure out why the original capacitors are not starting it.
I had the start cap tested and a little over 100 microfarads and the run cap should be 30 but it tested at 22 microfarads. I don't know enough about electric motor theory to know if 8 microfarads in a 30 micorfarad run capacitor will make a difference???

The large siemens contactor buzzes as if getting low voltage so I checked and it gets 110 volts but the coil is rated for 220 volts. It is hard to imagine fuelmaker designed it this way??? Who knows what happened to it in its past lives?
Karl

[Amfuel]

Re: FMQ2-36 Dead....Need new board?

Most capacitors have a tolerance printed on them. +/- 2%, 5%,... You appear to have a 25% difference. That does not sound good.
A 220v coil with half power? Yeah that is an issue.

Installed the stock EM in a '96 FM4 today. It is gone.