Monday, December 07, 2015

YAMAHA YST-SW005 disassembling and circuit diagram

YAMAHA YST-SW005 

DISASSEMBLING AND 

DISASSEMBLY PROCEDURES
Remove parts in the order as numbered.
 For exchanging the driver unit
1. Removal of Front Grille
The front grille is fixed to the cabinet with dowels at 6 locations.
As a screwdriver (for slotted head screw) is used for removal, use special care not to cause damage to the cabinet.
a. Apply the block to the rear panel so as to avoid damage to the Terminal of the rear panel.
b. Use the screwdriver inserted in the gap between the front grille and the cabinet (bottom side first), push up the front grille.
c. Remove the front grille by lifting it up.
2. Removal of Driver unit and Replacement of LED
a. Remove 4 screws (1) in, and remove the Driver unit.
b. Disconnect the cord connected to the Driver unit.
c. Remove 4 screws (2) and pull out the port section forward. LED can then be replaced.


For repairing P.C.B.
1. Removal of Rear Panel
Remove 14 screws (2) in , and remove the rear panel. At this time, disconnect the connector CB5 of MAIN P.C.B. (1).
* When reassembling the rear panel which has been removed from the rear panel, be sure to replace the packing to prevent the air leakage.
2. P.C.B. Operation Check
Connect the connector CB5 of MAIN P.C.B. (1).

CONFIRMATION OF AUTO STANDBY OPERATION
Setting
1) Turn off the power switch.
2) In order to shorten the time required for operation check; connect a 10kOhm resistor at both ends of R60 on the MAIN P.C.B. (1).
3) Connect the output signal from the signal generator to the INPUT 2 of the unit.
4) Set the signal generator for the sine wave of 100Hz, 8mV.
5) Turn on the power switch.
Confirmation
1) Set the AUTO STANDBY switch to the LOW position.
2) Turn on the POWER switch. The display LED lights up (green) and its color changes to red after 5 to 10 seconds.
3) Turn off the POWER switch. The display LED goes off.
4) Set the AUTO STANDBY switch to the HIGH position.
5) Turn on the POWER switch. The display LED lights up (green) and its color remains unchanged even after time have elapsed.
6) Turn off the POWER switch. The display LED goes off.
After confirmation
1) Turn off the power switch.
2) Disconnect the 10kOhm resistor connected to both ends of R60.
CIRCUIT DIAGRAM 
CLICK ON THE IMAGE TO ZOOM IN