Hi all,
my NAD c326bee has serious problem. It keeps turning on and the buttons on front of the panel are irresponsive and also the standby button. The only mode to turn the amp off is to use the hardware switch on the back panel. When the amp is in this state (power on but irresponsive), it becomes quite hot. The problem was fixed in april with a quite expensive repair, now the problem returns.
Is there a way to fix this weird malfunction?
Thanks
my NAD c326bee has serious problem. It keeps turning on and the buttons on front of the panel are irresponsive and also the standby button. The only mode to turn the amp off is to use the hardware switch on the back panel. When the amp is in this state (power on but irresponsive), it becomes quite hot. The problem was fixed in april with a quite expensive repair, now the problem returns.
Is there a way to fix this weird malfunction?
Thanks
this model is a calamity.
John Snell, if he passes by there may be able to help you.
on my side, I'm content to recover some transistor and I have the rest in the trash, at least that's what I did for the five that passed me in the hands
John Snell, if he passes by there may be able to help you.
on my side, I'm content to recover some transistor and I have the rest in the trash, at least that's what I did for the five that passed me in the hands
There's probably something wrong with the microcontroller. I'd try replacing it's oscillator crystal (20MHz) first. I'd also check the +5V supply for noise.
(edit) Looking at the schematic, I see the Standby supply is a switchmode circuit based on a TNY274. I'd replace C608/C609 with high quality 330uF 16V capacitors. Make sure they are low ESR types such as Panasonic FC.
(edit) Looking at the schematic, I see the Standby supply is a switchmode circuit based on a TNY274. I'd replace C608/C609 with high quality 330uF 16V capacitors. Make sure they are low ESR types such as Panasonic FC.
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I changed the components suggested, now the amp is more stable: it remained in standby for 2 days. Yestarday, it's switched on. I switched it off and now it's in standby again. The +5V seems good. Surely it's more stable but not completely fixed. The pcb around the HCF4094B is strangely swollen, I had to remake a trace that fallen apart.
Hi,
after one month and half, the problem has returned with the same symptom: front panel is unresponsive after the amp has turned on..😕
NAD 326 BEE usual issues ?
Hello .. I see you are in Britany as I am. I have just bough a second hand NAD 326 BEE from LBC, will receive it soon, and unfortunately I do see you worrying comments a bit late... Mine is 3 years old, ie manufactured in 2016/2017 apparently. It is supposed to work well, alltough may be there is a good reason it was for sale !
I'm an engineer in electronics, so able to repair myself. For help, as seems you have a backgroud, is there a list of klown default / solutions to be known ?
Thks
Hello .. I see you are in Britany as I am. I have just bough a second hand NAD 326 BEE from LBC, will receive it soon, and unfortunately I do see you worrying comments a bit late... Mine is 3 years old, ie manufactured in 2016/2017 apparently. It is supposed to work well, alltough may be there is a good reason it was for sale !
I'm an engineer in electronics, so able to repair myself. For help, as seems you have a backgroud, is there a list of klown default / solutions to be known ?
Thks
Hi everyone. I reopen this threads years later, I known.
Well, I have an extremely similar issue:
The C326keeps turning on, and switches automatically to MP input. Even when one choses another source, it also keeps going back to MP.
I did a quick check on the service manual, and I thought "maybe there is an automatic switch due to a false detection of a device connected to the front jack".
It does not seem to be the case.
My adventure can also be seen here.
Has anyone any idea how the issue of Pa67 was solved (if it was)?
Thanks
PS: I know it may well be the IC of the keyboard PCB. Does anyone knows where to get replacement part (the IC is a ATMEGA48, but I guess this requires the specific programming from NAD)?
Well, I have an extremely similar issue:
The C326keeps turning on, and switches automatically to MP input. Even when one choses another source, it also keeps going back to MP.
I did a quick check on the service manual, and I thought "maybe there is an automatic switch due to a false detection of a device connected to the front jack".
It does not seem to be the case.
My adventure can also be seen here.
Has anyone any idea how the issue of Pa67 was solved (if it was)?
Thanks
PS: I know it may well be the IC of the keyboard PCB. Does anyone knows where to get replacement part (the IC is a ATMEGA48, but I guess this requires the specific programming from NAD)?
Hi there...
So after I checked with repair shops that told me that either they would not do it, or that even if they would check, they expect the reparation to be at least 300 Euros, I checked again. Anyhow, I could then not use the amp.
I figured out that I could not reproduce the problem when the amplifier was roughly dismantled (notably the keyboard panel, but it happened again when mounted back. In my opinion, temperature as such would not be the major factor, as I could reproduce it in cold start (after a couple of hours off).
So I wondered whether there was not a mechanical issue, especially on the press button of MP. As the buttons on the front side are assembled two by two, I completely removed the MP button soldered on the keyboard panel (item S503 on p. 14 and 18 here).
No the amplifier as such is working without the issue... but none of the touch button is working (the remote is functioning flawlessly).
So as such I can use the amplifier (admittedly with the remote)... but I cannot understand why the buttons are not working. Anyone has an idea? Is there an invisible connection that the push button was somehow making (it's not obvious to me from the PCB diagram)? Has anyone an idea?
Thanks
So after I checked with repair shops that told me that either they would not do it, or that even if they would check, they expect the reparation to be at least 300 Euros, I checked again. Anyhow, I could then not use the amp.
I figured out that I could not reproduce the problem when the amplifier was roughly dismantled (notably the keyboard panel, but it happened again when mounted back. In my opinion, temperature as such would not be the major factor, as I could reproduce it in cold start (after a couple of hours off).
So I wondered whether there was not a mechanical issue, especially on the press button of MP. As the buttons on the front side are assembled two by two, I completely removed the MP button soldered on the keyboard panel (item S503 on p. 14 and 18 here).
No the amplifier as such is working without the issue... but none of the touch button is working (the remote is functioning flawlessly).
So as such I can use the amplifier (admittedly with the remote)... but I cannot understand why the buttons are not working. Anyone has an idea? Is there an invisible connection that the push button was somehow making (it's not obvious to me from the PCB diagram)? Has anyone an idea?
Thanks
Hi Gneuh. I had a similar issue with my C326BEE. It turned out that one of the tactile switches on the front panel was defective. These switches are easy and cheap to replace. Try this first. You may be surprised. Cheers
Hi, thanks... that's indeed what I ultimately did, by completely removing (unsoldering) the button, and it seems to work.
What I don't get is why, with this button for MP unsoldered, none of the tactile switch is functioning anymore.
But indeed, as you mentioned, that would potentially be the next step (if I am not too lazy), to replace the switch with a new one on component side.
What I don't get is why, with this button for MP unsoldered, none of the tactile switch is functioning anymore.
But indeed, as you mentioned, that would potentially be the next step (if I am not too lazy), to replace the switch with a new one on component side.
Hmmm, rechecking the PCB and the switch datasheet, I wonder if these switches are not also somehow uses as jumper. I will have to check (that is, I I have the courage to reopen the amp and dismantle it... it's working now, with the remote 😁)
OK... final (provisionally) update:
I can confirm that the switch is also used as a jumper for a signal (the switch itself has four pins, 1-2 are connected together, 3-4 are connected together, and the switch function is between 1-2 and 3-4. On the copper side layout of the NAD, a signal is coming to 1 and another to 2. The switch is indeed also a jumper, and is somehow bringing all the feedbacks from the tactile switches)
I wanted to replace the tactile switch, but I noticed that I has potentially scrapped some tiny copper tracks when unsoldering. So to be on the safe side, also mechanically, I replaced the switch by a simple jumper.
result: the amp is working, all the buttions are working (except obviously MP, there is not button anymore, but I am not sure I ever used it).
I can confirm that the switch is also used as a jumper for a signal (the switch itself has four pins, 1-2 are connected together, 3-4 are connected together, and the switch function is between 1-2 and 3-4. On the copper side layout of the NAD, a signal is coming to 1 and another to 2. The switch is indeed also a jumper, and is somehow bringing all the feedbacks from the tactile switches)
I wanted to replace the tactile switch, but I noticed that I has potentially scrapped some tiny copper tracks when unsoldering. So to be on the safe side, also mechanically, I replaced the switch by a simple jumper.
result: the amp is working, all the buttions are working (except obviously MP, there is not button anymore, but I am not sure I ever used it).