Onkyo TX-DS474 Service Manual - Page 3

TX-DS474 SERVICE PROCEDURES 1. Replacing the fuses -1- 1 -1- This symbol located near the fuse indicates that the fuse used is fast operating type. For continued protection against fire hazard, replace with same type fuse. For fuse rating refer to the marking adjacent to the symbol. -11 Ce symbole indique que le fusible utlise est a rapide. Pour une protection permanente, n'utiliser que des fusibles de meme type. Ce darnier est indique la qu le present symbol est appose. REF. NO. PART NO. DESCRIPTION F911 252166 A 6.3A-UL/T-237,Fuse 252198 A 8A-UL, Fuse F922 252077 or A 4A-SE-EAK or F933 252243 252075 or 252241 A 4A-SE-EAK,Fuse A 2.5A-SE-EAK or A 2.5A-SE-EAK, Fuse NOTE: : 120V model only : European model only : Worldwide model only : Asian model only : Australian model only 2. To Initialize the unit This device employs a microprocessor to perform various functions and operations. If interference generated by an external power supply, radio wave, or other electrical source results in accident which causes the specified operations and functions to operate abnormally. To perform a result, please follow the procedure below. 1. Press and hold down VIDEO 1 button, then press SPEAKER A button. 2. After "clear" is displayed, the prest memory and each mode stored in the memory, such as surround, are initialized and will return to the factory settings. 3. Safety-check out (Only U.S.A. model) After correcting the original service problem, perform the following safety check before releasing the set to the customer. Connect the insulating-resistance tester between the plug of power supply cord and the screw on the back panel. Specifications: 3.3 Mohm±10% at 500V. 4. Change of voltage Worldwide models are equipment with a voltage selector to conform with local power supplies. This switch is located on the back panel. Be sure to set this switch to match the voltage of the power supply in your area before turning the power switch on. This switch is set to 220V at the factory. Voltage is changed by sliding the groove in the switch with the screwdriver to the right or left. Confirm that the switch has been moved all the way to the right or left before turning the power switch on. VOLTAGE SELECTOR 220-230V- 120V- 5. Memory preservation This unit does not require memory preservation batteries. A built-in memory power back-up system preserves contents of the memory during power failures and even when the unit is unplugged. The unit must be plugged in and the power switch turned on and off once in order to charge the back-up system. Note that since this is not a permanent memory, the power switch must be turned on and off a few times each month the keep the back-up system operative. The period of the time during which memory contents are preserved after power has last been turned off varies depending on climate and placement of the unit. On the average, memory contents are protected over a period of 3 to 4 weeks (a minimum of 2 weeks) after the last time power has been turned off. This period is shorted when the unit is exposed to very high humidity or used in an area with an extremely humid climate. 6. Setting the tuning step frequency Worldwide models are equipped with a step band selector switch. This switch is located on the back panel. This switch is set to 9 kHz at the factory, but may have to be reset to 10 kHz depending on the area where the unit is used. AM band step Europe: 9 kHz AM FREQ. STEP U.S.A.: 10 kHz 9kHz 10kHz 7. Changing the band step With the exception of the worldwide models, a tuning step selector switch is not provided. When you change the band step, change the parts as shown below. R7035 R7036 R7037 R7038 To 10kHz Open Shorted Open Shorted To 9kHz 10kohm Open 10kohr Open -3-