MIMF

I have one of those grizzly air filters with three speeds and timer selections. After I moved last fall I was having some trouble with it when I was setting up my shop. At first it would not start with the remote. I could turn it on with the buttons on the unit. after a while the buttons stopped working, then they did work. It seemed like every time I would move it, it would start or stop working.

I set it aside and forgot about it until today. I was moving stuff and found the remote, hit the button and everything worked perfectly. I unplugged it and moved it to a good location and again it would not respond to the remote. But. . . The buttons on the unit worked. I took it down and moved it to my bench to work on it. Plugged it in and nothing worked. I Opened the case and removed the housing and everything worked. I unplugged it and plugged it in again and nothing.

I don’t see any loos wires or connections. I can’t figure out what could be going on. Is it as simple as the control board being bad? I wouldn’t expect it to ever work if that were the case.

To clarify, I took the control board out and see no evidence of damage. Nothing is gummed up, no swollen capacitors, no scorching of any kind. I can jump the power cord directly to the motor and it runs all three speeds just fine. So I know it is a problem with the board, I just don’t know what would be making it act so I consistently rather than just not working.

Intermittent short somewhere. They can be hard to find. Probably a fatigued wire that breaks circuit on slight movement. The first place you often see this is in the power cord which gets the most stress. But since you have the problem isolated to the control board, see if you can get it to turn on and off by carefully jiggling wires connected to the board.

The other thing to look for would be cold solder joints on the board, or perhaps a crack.

I don’t see any cracks what would a cold solder joint look like?

I had a problem like this with a shop vac. Turned out to be very fine dust in the switch. Could try giving the switches a blast of switch cleaner.

I went over the board with my optimist on and all of the joints look well soldered.

Here is the weird thing. I gave the switches a squirt of WD40 because that is all I had in hand. I plugged the board back in and the switches now work but the remote control only works partially. It responds inconsistently to the power/speed selection button and the timer button not at all. And, at one point switching between the timer setting dropped the motor down to low speed without hitting that button.

Frankly, I was surprised that cleaning the switches worked since the remote would not turn it on. I’m afraid to put it back together and install it because I’m sure it will just stop again.

Update: I’m not sure why I didn’t do this at the same time I cleaned the switches; I just took the remote apart and cleaned those buttons too. It seems to be working now. I think.

Ah, WD40 is not the right product for this and may be part of the problem now. You should get real contact cleaner because it is also the right product for cleaning guitar pots. WD40 can leave oil behind which is not conductive. So now you will need to clean the oil out of the switches.

In lieu of contact cleaner, you could use a squirt of denatured alcohol to clean the oil out of the switches.

Thanks, Barry. I’ll get some contact cleaner when I’m able to get out, hopefully some “essential” reason will come up. I have no electric guitars in the house but I’m sure once I have some, I’ll find lots of uses for it. Do you think the WD40 will be an issue in the mean time? Will it create more of a issues the longer I wait to clean it out?

Clean it out with alcohol.

Thanks!

WD 40 is fish oil Bryan. . . or it was.
Not good inn circuits.