Help! Electrical problem with my NAD amps

First posted to Hifi but little response as yet, so i thought i'd ask here.

I was wondering if anyone can give me some advice. I accidentally touched the left channel speaker cables together on my NAD C370 and it's completely dead. I can't find any fuses inside the amp at all. It has also blown 4 fuses I found in my NAD C350 which I was using as the pre-amp to bi amp the two power sections (350 for HF and 370 for LF). I think the surge through the 370 may have blown the pre amp in the 350 as the power light comes on but none of the input lights are working. One of the fuses has metal literally splattered all over the inside of the glass which doesn't bode well. I'm unable to check the power section of the 350 to see if that works. I am going to replace the 4 fuses (next to the toroidal transformer) in the 350 and hope I can at least have that working for now.

Any advice would be much appreciated. Thanks.

 

I thought this had output protection ?

shut down and unplug then switch back on....

if not you may have blown the output transistors ?

 

found this at......

http://207.228.230.231/manual/NAD-C370.pdf

standby protection indicator
Upon switching Power on, the indicator will light up red and after
a short pause turn to green to indicate the amplifier is ready for
use. In cases of serious abuse of the amplifier, such as
overheating, excessively low loudspeaker impedance, short
circuit, etc. the amplifier will engage its Protection circuitry. The
indicator will light up red and the sound will be muted. In such a
case, turn the amplifier off, wait for it to cool down and/or check
the speaker connections, making sure the overall loudspeaker
impedance doesn't go below 4 ohms or 8 ohms in Bridge Mode.
Once the cause for the protection circuitry to engage has been
removed, switch the amplifier On again.

 

thanks I tried all that, there is no light at all on the C370. On the C350 i found two blown fuses inside, replaced them and they blew again. i think it needs professional help...

 

just wondering, why do some hi fi shops (no names mentioned) sell all-metal banana plugs that fit very loosely in the speaker, that's what caused the problem. i've changed over to the cheapo type that are made of plastic and fit tightly so it won't happen again. i think the metal ones are unfit for purpose, is there some reason i can't think of why anyone would want to use them?

 

I think youve blown at least the output transistors......

with a new price of about £450 [c372] its probably worth a spending £100-£150 to get repaired. If your repair bill is bigger get them to do an engineers report for your insurance .....

In fact contact your house insurance and tell them what happened ....don't tell porkies be honest If you were moving the cables and the plugs weren't fit for purpose then tell them.

Chances are if you have a new for old plus accidental damage you will get a new amp and just pay the excess which may be less than the repair bill.

 

Phone Lenbrook on 01908 319360.

The service department there has always been very helpful and courteous for me.

One time my S300 went noisy on one channel and a transistor needed replacing. They had no problems about telling me exactly which one it was for me to do it myself.

When they repaired my S300 from it's big outage (o/p transistors on one side gone, similar problem to your C370 it sounds like) it was turned around quickly and cost less than £100.

 

you can't beat a personal recomendation...go for it !