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I'm planning to post 2 new threads (roll bar recover and secondary air pump/system replacement), but the knob on my factory radio finally died.
The knob on my radio has always mostly worked. It turned on and off perfectly, but managing the volume was never it's strong suit. A normal volume knob has a tactile soft click click to it's operation until it just freewheels and you lose all control. I had sprayed the knob (actually the volume rheostat encoder, VR401 on the circuit board) in the past to get it to function better, but this was much worse. I knew I needed a new encoder.
I called Becker Autosound about getting a new volume encoder, but they fix radios and aren't really a parts supplier. These guys do top notch work which justifies their fees, but I didn't want to be without tunes for the turnaround time. I looked up the part EN11-HSM3BF25, but it is out of stock at all the electronic parts places AND it has a 1 mm too thick shaft that needs shaving before the original knob can be attached.
What to do?
Crack open the encoder and fix it of course. I thought everyone might like to take a peek.
This is the busted part. That rotor is half the diameter of a dime and weights nothing. The flip side under the metal contact rotor has holes which makes it incredibly fragile, but my problem is that the rotor's hub disintegrated from the rotor. I picked the bigger pieces out from the center of the metal carrier (dark stuff at center of housing) and epoxy bonded a rebuilt hub back together. There are 15 rotor teeth and the serrated outer edge of the rotor has 30 detent stops.
This photo shows the encoder with the metal shaft carrier removed. If you look closely you can see that the 2 rectangular slots in the green base each have 2 metal feelers that "read" the toothed segments of the rotor. The metal top removes by bending the 4 metal attachment tabs. 2 on each side of the rheostat. 2 tabs can be seen on either side of the green LCD in the foreground. They are small tabs.
This is just the knob shaft housing and the green sensor base after the 2 parts have been separated with the rotor removed.
The rotor had to be cleaned and the hub rebuilt. Not too tough until I was cleaning the underside of the rotor when the rotor disc itself cracked underneath the metal surface. I put that back together.
The edge of the rotor is serrated like a coin, this coupled with a detent creates the tactile feedback when the knob it turned. You can see the detent embedded in the left side of the metal knob shaft housing.
I'm in the exact same boat. I'm wondering before I super glue the shaft to the contact disc, would that affect the push button effect?
Right now, my push button effect is perfect, radio turns on and off fine. However the volume knob spins freely. Since it is separated from disc, I don't have the clicky noise either.
I'm planning to post 2 new threads (roll bar recover and secondary air pump/system replacement), but the knob on my factory radio finally died.
The knob on my radio has always mostly worked. It turned on and off perfectly, but managing the volume was never it's strong suit. A normal volume knob has a tactile soft click click to it's operation until it just freewheels and you lose all control. I had sprayed the knob (actually the volume rheostat encoder, VR401 on the circuit board) in the past to get it to function better, but this was much worse. I knew I needed a new encoder.
I called Becker Autosound about getting a new volume encoder, but they fix radios and aren't really a parts supplier. These guys do top notch work which justifies their fees, but I didn't want to be without tunes for the turnaround time. I looked up the part EN11-HSM3BF25, but it is out of stock at all the electronic parts places AND it has a 1 mm too thick shaft that needs shaving before the original knob can be attached.
What to do?
Crack open the encoder and fix it of course. I thought everyone might like to take a peek.
This is the busted part. That rotor is half the diameter of a dime and weights nothing. The flip side under the metal contact rotor has holes which makes it incredibly fragile, but my problem is that the rotor's hub disintegrated from the rotor. I picked the bigger pieces out from the center of the metal carrier (dark stuff at center of housing) and epoxy bonded a rebuilt hub back together. There are 15 rotor teeth and the serrated outer edge of the rotor has 30 detent stops.
This is just the knob shaft housing and the green sensor base after the 2 parts have been separated with the rotor removed.
The rotor had to be cleaned and the hub rebuilt. Not too tough until I was cleaning the underside of the rotor when the rotor disc itself cracked underneath the metal surface. I put that back together.
The edge of the rotor is serrated like a coin, this coupled with a detent creates the tactile feedback when the knob it turned. You can see the detent embedded in the left side of the metal knob shaft housing.
I'm in the exact same boat. I'm wondering before I super glue the shaft to the contact disc, would that affect the push button effect?
Right now, my push button effect is perfect, radio turns on and off fine. However the volume knob spins freely. The shaft is separated from the disc just like yours. Now I notice that the shaft has two movements, one to spin, thereby causing volume changes, and one linear that allows it to be depressed to turn radio on/off. If I superglue the shaft to the disc, won't this linear motion be affected given that everytime I try to depress the volume knob, it'll depress the disc with it also?
The knob shaft is meant to slide in and out of the disc for the push ON/OFF function. If you solidly mount the disc to the shaft, you would lose that function.
You have to find a way to rebuild/build up the disc center section so it engages the outer disc AND provides a new foundation for the shaft to slip in and out as the volume knob is pressed ON/OFF.
It wasn't easy and the tiny size didn't help.
Now that I know that the volume disc is made of fragile plastic, SPRAYING IT WITH CONTACT CLEANER (most likely a plastic solvent) probably wasn't the best idea.
If the task proves too delicate (there are a bunch of parts and tolerances that must be considered), Becker Autosound will replace the part for you.
My volume knob is still working perfectly after this repair.
The knob shaft is meant to slide in and out of the disc for the push ON/OFF function. If you solidly mount the disc to the shaft, you would lose that function.
You have to find a way to rebuild/build up the disc center section so it engages the outer disc AND provides a new foundation for the shaft to slip in and out as the volume knob is pressed ON/OFF.
It wasn't easy and the tiny size didn't help.
Now that I know that the volume disc is made of fragile plastic, SPRAYING IT WITH CONTACT CLEANER (most likely a plastic solvent) probably wasn't the best idea.
If the task proves too delicate (there are a bunch of parts and tolerances that must be considered), Becker Autosound will replace the part for you.
My volume knob is still working perfectly after this repair.
This is monumentally helpful! Thank you.
So my issue, as I have unfortunately learnt, was that the fragile plastic had disintegrated behind the contact disc, likely because of the WD40 Contact Cleaner I'd used on it while the stereo was still connected, thereby causing it to be jammed in the metal housing. It wouldn't turn at all even after I gorilla glued the shaft to the disc (thinking the push button is not as useful as the volume if the radio stays forever ON, I can just lower the volume to achieve an off-like state). It came out in pieces
Only solution is to get another Encoder and swap it. Question: where might I find an exact replacement volume encoder for my Becker BE 1350 Special?
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