Mackie-Acoustics8BUS-mix-sb1 电路图 维修手册.pdf

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1、SR408 rework instructions SSE Oct 2000 SR40-8rework.pdf, page 1 of 4 SR408 and SR568 rework instructions Models affected: SR408 and SR568 Symptom: Various failures Possible Cause: Susceptability of the mixers to static discharge and power spikes. Solution: Rework the circuit boards by adding bypass

2、capacitors and associated components in various locations. Safety Warning: Caution! These instructions are for use by qualified personnel only. To avoid electric shock, do not per- form any servicing unless you are qualified to do so. Refer all service to qualified personnel. Boards to be reworked:

3、1Brain board assembly055-169-00 2Output digital board055-101-00 3Mono channel boards055-067-00 4Stereo channel board055-071-00 5Master output board055-074-00 Tools Required: Phillips head screwdriver, 1/16” Allen wrench, needle nose pliers, electrical cutters, soldering iron, solder, safety glasses,

4、 RTV silicone adhesive (electronic grade to secure cables), 3 loaves of bread and a French maids outfit. ESD Warning: Caution! Each board should be treated and repaired using ESD precautions. Preliminary: The rework involves removing most of the circuit boards, so the top and bottom of the console m

5、ust be accessable. Procedure: 1.Remove all cords (including the power cable and input cable) from the console. 2Remove the bottom from the console to expose the boards to be removed. The pages which follow show the rework required on each board. RadioFans.CN 收音机爱 好者资料库 ? ? ? ? ? ? ? ? SR408 rework i

6、nstructions SSE Oct 2000 SR40-8rework.pdf, page 2 of 4 Rework procedure for the Brain board 055-169-00: The Brain board and the output digital board are both mounted to the stiffener inside the console. 1.Make a note of the placement and direc- tion of all cables to these boards, then remove the Bra

7、in board by undoing the four screws. 2.Add a 0.1uF capacitor across Pin 1 (+5VDC) and Pin 2 (GND ) of the voltage regulator (U10). 3.Add a 0.01uF capacitor between Pin 2 (GND ) and chassis ground (stand-off). Use a solder lug (not shown). 4.Add a 0.1uF capacitor across connector J2-pin 3 (+5VDC) and

8、 J2-pin 2 (digital ground). 5.Add a 0.01uF capacitor between J2-pin 2 (digital ground) and chassis ground (stand- off). Use a solder lug (not shown). 5.Add two 10k, 1/8th Watt pull-up resistors across the Eprom devices: U11-pin 8 to U11-pin 5, and across U9-pin 8 to U9-pin 5. (Vcc and SDA). RadioFan

9、s.CN 收音机爱 好者资料库 ? ? ? ? ? ? ? ? SR408 rework instructions SSE Oct 2000 SR40-8rework.pdf, page 3 of 4 Rework procedure for the Output Digital board 055-101-00: 1.Make a note of the placement and direc- tion of all cables to the Output Digital board, then remove it by undoing the screws. 2.Add a 0.1uF

10、 capacitor across connector J1-pin 3 (+5VDC) and J1-pin 2 (digital ground). Rework procedure for each Mono Channel board 055-067-00: 1.Remove the cables from the back of the mono channel 1-8 board. 2.Using a 1/16” Allen wrench, remove the 15 button head screws from the top surface of the console, fo

11、r channels 1-8. 3.Move the board back slightly and gently remove the cables running from the channel board to the mono pod, and remove the board. 4.Add a 0.1uF capacitor across connector J7-pin 14 (+5VDC) and J7-pin 13 (digital ground). 5.Add a 0.01uF capacitor between J7-pin 13 (digital ground) and

12、 chassis ground (stand-off). Note the use of a solder lug is recommended, as shown. 6.Repeat for all remaining mono channel boards. RadioFans.CN 收音机爱 好者资料库 ? ? ? ? ? ? ? ? Rework procedure for the Stereo Channel board 055-071-00: 1.Remove the cables from the back of the stereo channel board. 2.Using

13、 a 1/16” Allen wrench, remove the 10 button head screws from the top surface of the console. 3.Move the board back slightly, and gently remove the cable running to the master pod and the cable running to the master meter, and then remove the board. 4.Add a 0.1uF capacitor across connector J7-pin 14

14、(+5VDC) and J7-pin 13 (digital ground). 5.Add a 0.01uF capacitor between J7-pin 13 (digital ground) and chassis ground (stand- off). Note the use of a solder lug is recom- mended. Rework procedure for the Master Output board 055-074-00: 1.Remove the cables from the back of the Master output board, p

15、aying particular attention to where they connect to and their direction. 2.Using a 1/16” Allen wrench, remove the 23 button head screws from the top surface of the console. 3.Move the board back slightly, and gently remove the two cables running to the master pod, and then remove the board. 4.Add a

16、0.1uF capacitor across connector J18-pin 2 (+5VDC) and J18-pin 1 (digital ground). This is located along the bottom edge of the board, and the cap can be added on the component side. Finishing up: 1.Before reinstalling the boards into the console, clean the metal chassis surface where the standoffs

17、(chassis ground) will make contact. Clean off any paint, oxida- tion, or any other contamination. 2.Re-install all cables and secure the connec- tions with silicone RTV to ensure the cables dont come loose. 3.Perform a complete specification and safety test before returning the console to your customer. SR408 rework instructions SSE Oct 2000 SR40-8rework.pdf, page 4 of 4