Diagnosing and repairing blown Recieiver after connecting 3 ohm subwoofer to an 8 ohm reciever

XheisenburgerX

Commendable
Aug 23, 2016
2
0
1,510
Hello Everyone,

The knowledge I gained in 2 semesters of physic is the extent of my knowledge of electronics. This naivety is no excuse for my foolish decision to connect a 3 ohm subwoofer to a receiver that is rated for 8 ohm speakers.

After cranking the volume up, the receiver shut down. Any attempts to turn it back on result in the system shutting down about 10 seconds later and electrical smoke (if that is even what it is referred to as). I notice that the source of the smoke is a resistor that is labeled as R202.

Before I send it in for a replacement ($50), I figure this could be an opportunity to learn how to diagnose and fix this problem. So my questions are:
1) How can I diagnose the root of the problem?
2) Can you provide any databases or websites that may help educate me?
3) Based on my scenario, what damage is likely to have occurred?
4) How can I fix this problem (or what websites should I go to to learn how to fix this problem)?
 
This should be a relatively easy fix without having to acquire an electronics degree.

The R202 mostly likely is a sacrificial resistor, just replace it *should* do the trick. If you are lucky the value of the resistor is stenciled on the circuit board, if not, you will have to find a schematic. Vendors, long time ago, published these things, but these days, it's throw-away society so they don't expect you to repair this stuff. At the end, may have to pay the PROS for the job.
 

XheisenburgerX

Commendable
Aug 23, 2016
2
0
1,510


Thanks! I know the resistor is a 1 ohm resistor with 20% tolerance (based on the rings). Now I am having trouble determining the wattage for the resistor. I assume this is something that will need to be found on a circuit schematic?