Removing NAD T753 Volume Control Knob

[sonicrealism]

I am trying to recover use of the control buttons on the front panel of my NAD T753. Not sure what happened, but a good summary is "blunt force trama" probably from my kids playing pushed the Tone Defeat into the faceplate. I nolonger can use any controls on the front panel ... except for tone defeat. (go figure!)

I want to carefully dismantle enough of the unit to allow me to see what actually happened. But I am now stuck.

I need to remove the Volume Control Knob for the motorized control. The control body itself is welded to a circuit board. I *hope* that if I remove the knob on the front, I will see a nut or something around the shaft that I can then remove allowing me to remove the board from the back of the front face plate.

How do you get the knob on the outside of the unit off? It is firmly attached.

Thanks.

[Bigred]

Hi sonicrealism,

I have never seen one of these receivers but if the knob does not wanna just pull off don't force it obviously. I would look for a small set screw or something on the backside of the face plate/front panel. Rotate the knob end to end as it might be in a position you can't see easily.

[sonicrealism]

Hell, Bigred. Your idea is a good one. Unfortunately, no such options exist. No set screw is visible outside on the front. Inside, there is a housing that is glued to the backside of the faceplate. The control is up against the back of that housing in its center. Noting can be seen on the backside of the faceplate that rotates; it is fixed as in glued in place. There is no access hole through the circuit board that the control is mounted on either.

Surely such controls are not designed as a oneshot; put it together and it will never come apart. I have to believe it must be possible.

Then again, I put some force into working the knob off the shaft. No movement. And as you suggested, if it will not come off easily, better to not force it.

[I have since discovered, btw, that the momentary contact for the tone defeat apparently is shot. The trama did that one in. I still need to get the board off to work on it, though.]

Any other ideas?

[Bigred]

2 more suggestions besides taking it to a competent NAD repairer. 1. Buy the service manual (It will have an assembly diagram.) and it may come in handy later anyways. I still think its gotta be a set screw or something over looked. Look over the knob closely on the front and the back through the entire circumference . I have seen NAD knobs held on with a screw through the knob on the front side of the panel 2. Post some pics of the unit and lets have a look.

[sonicrealism]

Your suggestion to buy the manual is a good one. The NAD repair shop in town here simply said that beyond fuses and simple things, they ship units back to the factory. Not something I want to do for such a "trivial" type repair (yeah, and therein is where I know just enough to be dangerous!).

Anyway, I was suffering from withdrawl and wanted to get the unit back online last night. I was able to dismantal enough to see that the little plastic button pressed through the faceplate was forcing the momentary contact into continuous contact. Wiggling it would toggle it but keep still maintain contact. That was locking out all other front panel inputs. I suspected that would be the case. I was able to put a probe between circuit board and the switch to put the button back into position. The momentary contact switch on the circuit board is shot. The spring tension to "pop" it back is not working. However, it does not make continuous contact. All other functions are back. Indeed, the tone defeat button is also working but without the ear-satisifying "pop" and finger-pleasing "snap" characteristics. Small loss. I don't plan on reselling this anytime soon. (I have a second two channel setup for critical audio-only listening that is the subject of planned upgrades.)

Bottom line, the unit is functioning 100%. Cosmetics look good. Tacticle feedback is compromised. I'll live with that.

I suspect I will need to open it up again someday, so I will explore you suggestion to get the manual. Do you know for sure they will sell one?

Thanks again.

[gmphadte]

Just a possibility...
Check whether the knob is made from two pieces(chuck type). Normally in such case, the front face will be a cover and is press fitted on to the cylinder. Pop up the cover and u will find a screw.

Sometimes, manufacturers will use glue on the shaft, which will make hand pulling the knob, quite difficult.

Gajanan Phadte

[Bigred]

Glad to hear you "macgyvered" it to function again. As far as the sevice manual this is from NAD FAQ's http://nadelectronics.com/index

Q: Can I purchase the schematics for my NAD unit?
A: We do not normally provide schematics, however, it MAY be possible to purchase service manual/schematics from our distributor for NAD electronics in your country. To locate your distributor, please check the NAD web site under the "dealers" section and contact the NAD Distributor in your country