HK 3490 (serv.man2) - Harman Kardon Audio EMC - CB Certificate (repair manual). Page 50

 

 

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 Report 

No. 

98503 

 
 

*), C309, S-c;  
Left speaker output signal off immediately. 
Input current stabilised at 1,03A. R353 damaged. 
No hazard. (Tested time; 3.0 min) 

N/A N/A 

*), Right speaker, S-c;  
Right speaker output signal off immediately. 
Input current stabilised at 1,15A. Q321, Q322 damaged.   
No hazard. (Tested time; 30 min) 

N/A N/A 

*), Ventilation opening (Blocked);  
Unit shut down after 8 min. Input current stabilised at 0,008A.  
No component damaged. Dielectric strength test O.K.  
No hazard. (Tested time: 16 min) 

N/A N/A 

*), Pmax. Operating (Maximum non-clipped output signal);  
 
1st.  
Winding of main transformer heated up to 159K and thermal fuse opened 
after 31 min. Input current stabilised at 0,008A.  Dielectric strength test O.K. 
No hazard. (Tested time: 31 min)  
 
2nd.  
Winding of main transformer heated up to 161K and thermal fuse opened 
after 10 min. Input current stabilised at 0,008A. Dielectric strength test O.K. 
No hazard. (Tested time: 10 min) 
 
3rd.  
Winding of main transformer heated up to 149K and thermal fuse opened 
after 10 min. Input current stabilised at 0,008A. Dielectric strength test O.K. 
No hazard. (Tested time: 10 min) 

 
 
 

Main transf. 

See #) below  

 
 
 

Main transf. 

See #) below 

 
 
 

Main transf. 

149 

 
 
 

Main transf.

150 

 
 
 

Main transf.

150 

 
 
 

Main transf.

150 

 

 

 

*)  Tested voltage 253V               **)  Tested voltage 198V

#) The temperature rise of the main transformer was measured to > 150K of allowable limit, but 
transformer passed the testes described in sub clause 11.2.5 (tests repeated three times). 

F No = Fault Number, S-c = Short-circuit, Dis = Disconnection, O-I = Over Loaded