Newcastle R-956: Where there's smoke...

[JimLish]

I have a 5 year old Newcastle R-956 integrated amp that recently developed a smoking problem. The other night, I turned the amp on, heard a crackling noise and saw a little smoke coming from the amp. I removed the cover (after unplugging of course) and was able to take a pic of the location of the short/arcing. It doesn't look like there was too much damage, but I am not sure of the cause or how to fix (I am waiting to hear from the manufacturer to see if they will fix it first)- I am mainly concerned about it happening again and causing a fire. Any advice is appreciated.

Thanks,

Jim

[XEAGLEKEEPER]

Looks like a couple output devices are toast


Have any idea what the part numbers are ?

[JimLish]

I can't see the part number- it's under the board and the only way I can see to get to them is by de-soldering all of the connections.

Any idea what would cause the short/arcing?

[jaycee]

I'm guessing they will be Sanken SAP15 devices. With discolouration like that, they will be toast and need to be replaced.

Newcastle would be a brand name of Sherwood
The quality of construction looks awful! That PCB material is like the cheap crap that I buy from Maplin because it's cheap

[XEAGLEKEEPER]

Reason for catastrophic failure:

1. Overdriven into sustained clipping/distortion.

2. Shorted output cables.

3.thermal fatigue. P-N junction just chose to "checkout"

[JimLish]

How can I get to the screw heads to replace the transistors (they are under the board with ~1 inch of clearance)? Sorry if this is a stupid question - I don't have any previous experience doing these kind of repairs, just building an occassion computer and other basic DIY projects.

[anatech]

Hi JimLish,
Desolder the leads and lift the board off. It's actually very easy to do.

-Chris