NAD C316BEE - V2 version ( schematics ? )

dray177 · 2023-02-04 5:41 pm

Dear All,

My Nad C316BEE is broken : it does not turn on !
To fix it, I am looking for the schematics ( service manual ).
Of course there is service manual online, but for only the initial version.
Mine, version V2, has the Main VM3.0 card, with a different diagram.
Also totally different the POWER SWITCH board.
Without these diagrams, I do not know how to repair ( possible that it is problem with +5volts lost ? ).

If any of you had the diagrams ( sm will be the best ) for this V2 version...
And if he agrees to communicate them,
I will be eternally grateful to him !!!

Raymond
( pardon me for my poor English, I am French )

Carte POWER SWITCH VM1.0 ( endroit ) .JPG

Audio Service · 2023-02-04 8:25 pm

On the start up circuit board check D63, P6KE200A unidirectional transient voltage suppressor to ensure it has not gone short.
The start up circuit board provides the 5 volt signal to the microprocessor.
If the board is not providing 5 volts the Amplifier will not start up.

Hiten · 2023-02-05 5:28 am

Member RS232 has posted a schematic of C315 HERE. Would there be much difference? I know C316 v2 only had phono and media player input added compared to V1. Rest was same. So probably C315 would also be same.
regards

dray177 · 2023-02-05 10:33 am

Audio Service said:
On the start up circuit board check D63, P6KE200A unidirectional transient voltage suppressor to ensure it has not gone short.
The start up circuit board provides the 5 volt signal to the microprocessor.
If the board is not providing 5 volts the Amplifier will not start up.

Dear,
Thank you very much for your reply and advice.
I just tested D63 : it is OK !
Yes, you are right, it is on this Power Switch board, - and only for this V2 version of the C316BEE ( with MAIN board Vm3.0 year 2012 ) - the +5v is made
Unlike the V1 version, where the +5v was produced on the MAIN board ( Vm1.0 year 2010 ).
In my case, +5v is dead.
The only service manual available is dedicated to first version ( MAIN board Vm1.0 ) .
So, I don't have the diagram for my V2 version, that means impossible to understand !
To try however, I have already changed ic62 ( TNY274PN ) and ic61 ( PC817C ) on the reverse side : without success.
Now, I am out of ideas !!!
Raymond

ps : reverse side of Power Switch board

Carte POWER SWITCH VM1.0 ( envers ) .JPG

dray177 · 2023-02-05 10:43 am

Since I don't understand...
I also think to change ic63 ( one TL431 ) on the Power Switch right side card
Raymond

jony · 2023-02-05 11:18 am

You should start by checking if there is around 320V present across input capacitor C67 (400V electrolytic capacitor)? Also, you should replace C68.

dray177 · 2023-02-05 2:39 pm

Thanks Jony
Yes ! I have exactly 320v across C66 ( 400v/10µF )
C68 ? I have across it 5 to 7v ( not stable )
C68 seems OK to capacitance meter measurements
But I will follow your idea : I will change C68...
Raymon

dray177 · 2023-02-05 3:22 pm

Just changed C68 ( 47µF/50v )
And nothing better to say !!
Raymond

dray177 · 2023-02-05 5:22 pm

There, I just found the NAD M50 SMPS board diagram : I think this diagram would be very close for the C316BEE ( that I am looking for ! ) and used to create the +5volts.
The components numbering is of course different on the C316BBE Power Switch.
What allow me to understand a little how it works !!!
And hope to help me...
Raymond

lineup · 2023-02-05 5:33 pm

You can find the service manual at https://audiocircuit.dk/
With schematics
But I'm afraid that is the version 1

dray177 · 2023-02-05 5:51 pm

Dear Lineup
Alas, this is ( as always ) the sm version 1
Raymond

lineup · 2023-02-05 6:01 pm

The difference according to NAD is that they have added a phono stage.
Most of the amp should be same.
I own a NAD C316BEE v1 myself.
It is a very good choice and gives a lot of quality for little money.

jony · 2023-02-05 7:14 pm

Can you measure pin 2 voltage of a TNY274. It should be around 5.8V.

dray177 · 2023-02-05 7:37 pm

Dear Jony,
You are Great !!!
pin 2 / ground = + 5,81v
Previously I changed : ic62 ( TNY274PN ) and ic61 (PC817C)
Then, I only think ic63 ( TL431 ) which could be the culprit : I bought it and I am waiting it for changing it.
Raymond

Audio Service · 2023-02-07 9:43 am

Audio Service · 2023-02-07 9:44 am

This is the C316 V2 Power Switch Circuit

thimios · 2023-02-07 10:33 am

Did you measure voltage direct on the D67 cathode?
Did you measure the output for a short circuit?
Measure the R66 for open circuit.

dray177 · 2023-02-07 3:28 pm

Audio Service said:
This is the C316 V2 Power Switch Circuit

You are absolutely the Best !
And thanks a lot !!
With your help ( this V2 diagram ), and if I am not a complete idiot, I should be able to... ...
Raymond

dray177 · 2023-02-08 6:59 pm

I am out of home since yesterday, till this saturday...
Hope this week-end to dip again my nose in my NAD
Raymond

dray177 · 2023-02-10 5:55 pm

Thanks to AUDIO-SERVICE, and with the help of its diagram...
the Nad is repaired.
It was necessary to change D63 ( D63 = diode P6KE200A ) : this was the culprit.
Again, thank You All.
Because without your help, I think, I would not have been able to finish it.
Raymond