Hello.
NAD C315BEE rest in Protect mode.
The led is red.
I shorted 7 & 8 pins on protection module
and I have -30v DC on left channel.
Right channel is OK.
Where I need control.
All power transistors are OK.
Thanks.
SM.
https://www.google.com/url?sa=t&sou...FjAAegQIARAB&usg=AOvVaw0rYZaOxU9MC691wtzT_epm
NAD C315BEE rest in Protect mode.
The led is red.
I shorted 7 & 8 pins on protection module
and I have -30v DC on left channel.
Right channel is OK.
Where I need control.
All power transistors are OK.
Thanks.
SM.
https://www.google.com/url?sa=t&sou...FjAAegQIARAB&usg=AOvVaw0rYZaOxU9MC691wtzT_epm
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You likely have shorted NPN outputs and possibly drivers. Use your DMM and test the outputs and move backwards on the schematic until you find good transistors. Also check any resistors around the bad transistors.
R175 is a shunt to ground in the output circuit - should have close zero DC and only AC as output signal.
R176 looks to be part of a RCL on the output circuit.
You either have a shorted transistor that is allowing 30Vdc to the output circuit (my best guess). Or you have oscillations and that is creating heat, but wouldn’t show as DC on the output, as it would be AC oscillation.
R176 looks to be part of a RCL on the output circuit.
You either have a shorted transistor that is allowing 30Vdc to the output circuit (my best guess). Or you have oscillations and that is creating heat, but wouldn’t show as DC on the output, as it would be AC oscillation.
Not if you have -30VDC on the output. The protection circuit is doing what it's supposed to do.
I replaced all bad transistors and resistors.
No protect mode..
Amplifier power on,2 channels works,
Idle current ok 7.5mv.
I turned on the music quickly, not very loud
But some resistors are very hot......
For example r268,r168,r190,r290...even in sleep mode
No protect mode..
Amplifier power on,2 channels works,
Idle current ok 7.5mv.
I turned on the music quickly, not very loud
But some resistors are very hot......
For example r268,r168,r190,r290...even in sleep mode
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Those are 3 watt resistors, so even if over-spec'd by 1 watt (which they probably closer to 0.5w over sized), dissipating 2 watts would create quite a bit of heat. The fact that you have consistency, would indicate it is as designed.
You could measure voltage drop across the resistor and calculate the power dissipation to be sure.
You could measure voltage drop across the resistor and calculate the power dissipation to be sure.
Those are 3 watt resistors, so even if over-spec'd by 1 watt (which they probably closer to 0.5w over sized), dissipating 2 watts would create quite a bit of heat. The fact that you have consistency, would indicate it is as designed.
You could measure voltage drop across the resistor and calculate the power dissipation to be sure.
You could measure voltage drop across the resistor and calculate the power dissipation to be sure.
If the volume level is low all ok.
If volume level 12 clock the Q215&Q217 are dead with R281,R260 blown and Q216 and
Q211 blown also....
If volume level 12 clock the Q215&Q217 are dead with R281,R260 blown and Q216 and
Q211 blown also....
Its solved.
The 2 output transistors Toshiba 5200 and 1943 buyed on eBay was fake.
The genuine transistors monted and Amplifier works fine.
Thank you.
The 2 output transistors Toshiba 5200 and 1943 buyed on eBay was fake.
The genuine transistors monted and Amplifier works fine.
Thank you.
As a courtesy - can you post the eBay seller on here so others can avoid these fakes? Picture of listing preferred.
I wrote to the seller that the transistors are fake. he took them off the sale and returned the money to me. he is a good seller, I bought a lot from him. I can't give his name as he fixed everything.