Hunter Ceiling fan remote repair

[billdlv]

I have 2 ceiling fans that are pretty old (2007).  Both still work well, are quiet and other than problems with the remotes they work fine.  They do not have any pull chains or manual switch for forward / reverse.  This is a problem for trying to get a receiver / remote replacement.  The manufacture does not have the remote anymore, and I have searched and checked and have not been able to find one.  I found a place that sells remotes and the guy was very helpful, he told me that there is not an easy way to upgrade the remote / receiver because of the lack of a reverse switch and the receiver is an above the blade style.

The 1st problem with both remotes was that the LED indicator light on the remote would stay on dimly even if no buttons are pressed.  I took the remotes apart and cleaned the contacts and button pads with IPA, but the problem still persisted.  I found a video on youtube, and in the comments someone stated that the transistor at Q4 goes bad and to remove it.  This will make the LED no longer function, but will stop the battery drain.  I did this on both remotes and it fixed that problem.

The 2nd problem is with one of the remotes, some of the speed buttons do not work anymore.  The off button, low speed and direction button do not work.  The light button, medium speed, and high speed buttons work.

I'm attaching photos of the remotes and the board, which is single sided.  I did not take a photo of the other side of the board, the only components are the antenna and a 350 Mhz crystal.  They are connected on the upper right of the board (crystal near R2, antenna C2 and Q1)

As I said, I have cleaned the board and the buttons with IPA.  I can measure the resistance of each and they are all around 3k.  I measured the resistors on the board in circuit and they seem Ok.  I made the mistake of measuring the diodes in circuit and some of them (D3, D4, and D2) measured voltage when reverse biased, so I replaced them thinking they were bad.  Turns out they were not when I measured them out of circuit.

I have a Hantek DSO1062B (60 Mhz) that I put across the loop antenna.  I can see a signal, which I assume is a harmonic since the remote operates at 350 Mhz?  I can see a signal each time I press any of the buttons.

Any ideas on what could be wrong?  I looked over the solder connections on the board under magnification and I don't see anything wrong.  I'm trying to think what would go bad on the remote and the only thing I see is the contact between the carbon buttons and the traces on the board, but they measure Ok and I can see signal with the scope.  I have confirmed it is the remote that is bad, if I take the other good remote and set the jumper for the fan, all controls work (eg the one good remote works all functions on both fans).

[Raj]

I have 2 ceiling fans that are pretty old (2007).  Both still work well, are quiet and other than problems with the remotes they work fine.  They do not have any pull chains or manual switch for forward / reverse.  This is a problem for trying to get a receiver / remote replacement.  The manufacture does not have the remote anymore, and I have searched and checked and have not been able to find one.  I found a place that sells remotes and the guy was very helpful, he told me that there is not an easy way to upgrade the remote / receiver because of the lack of a reverse switch and the receiver is an above the blade style.

The 1st problem with both remotes was that the LED indicator light on the remote would stay on dimly even if no buttons are pressed.  I took the remotes apart and cleaned the contacts and button pads with IPA, but the problem still persisted.  I found a video on youtube, and in the comments someone stated that the transistor at Q4 goes bad and to remove it.  This will make the LED no longer function, but will stop the battery drain.  I did this on both remotes and it fixed that problem.

The 2nd problem is with one of the remotes, some of the speed buttons do not work anymore.  The off button, low speed and direction button do not work.  The light button, medium speed, and high speed buttons work.

I'm attaching photos of the remotes and the board, which is single sided.  I did not take a photo of the other side of the board, the only components are the antenna and a 350 Mhz crystal.  They are connected on the upper right of the board (crystal near R2, antenna C2 and Q1)

As I said, I have cleaned the board and the buttons with IPA.  I can measure the resistance of each and they are all around 3k.  I measured the resistors on the board in circuit and they seem Ok.  I made the mistake of measuring the diodes in circuit and some of them (D3, D4, and D2) measured voltage when reverse biased, so I replaced them thinking they were bad.  Turns out they were not when I measured them out of circuit.

I have a Hantek DSO1062B (60 Mhz) that I put across the loop antenna.  I can see a signal, which I assume is a harmonic since the remote operates at 350 Mhz?  I can see a signal each time I press any of the buttons.

Any ideas on what could be wrong?  I looked over the solder connections on the board under magnification and I don't see anything wrong.  I'm trying to think what would go bad on the remote and the only thing I see is the contact between the carbon buttons and the traces on the board, but they measure Ok and I can see signal with the scope.  I have confirmed it is the remote that is bad, if I take the other good remote and set the jumper for the fan, all controls work (eg the one good remote works all functions on both fans).

Can you use an Arduino/microcontroller to program your own remote? Tip: remove bootloader and program it using another Arduino to get a normal speed remote (otherwise the boot up time will annoy you)
tip:read this thread: https://www.eevblog.com/forum/beginners/button-input-problem/msg2585181/#msg2585181