Marantz SR 7300 Service Bulletin

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Approved by H.TAMURAWritten by K.ONOWQ-19 2 817/additional rule3 (1st Issue 2003-03-19)Date :15-May-2003 ModelSR7300 Page :1/2 REF.NBR :MZ03-006 Circulation:Application: Subject: Int.ref :[ PHENOMENON] High tone noise can be heard a little from speaker. [SOLUTION] Please apply the modification of Solution 1 and Solution 2 to the units Lot 01 to Lot 15.Please apply the modification of Solution 2 to the units Lot 16 and after. (Solution 1 has already applied to the unitslot 16 and later.) * The lot number is mentioned in the Serial number label on the rear panel. ( ex. MZxxxxxx01xxxx : 01 lot) Solution 1 ( For lot 01 to 15)1) Cut a jumper wire [U304] on the PS04 board. 2) Add a capacitor < 1000uF/10V : Parts # OA10801020> between the pin 3 of the Q681 and the -side of the CU80 as follows. SERVICE BULLETIN Improvement of high tone noise xfor information customer complaint in case of service mandatory ...................ALLCut the Jumper wire [U304]Solder to the pin 3 of Q681Add and solder a capacitor 1000uF/16v. Solder + side of the capacitor to the pin 3 of Q681. And - side to the CU80( - side ) Add tube and fix the cap by glue.Solder to the - side of CU80

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Approved by H.TAMURAWritten by K.ONOWQ-19 2 817/additional rule3 (1st Issue 2003-03-19)MZ03-006 Page 2/2 Solution 2 ( For all lot)1) Add a wire (Length approx. 23cm : Wire size #18 or #20) as follows. (GND to GND) Note: Wiring must be done as following and fixed by glue (burn-resistant type).Add 23cm wireSolder to GND plateSolder to GND pin