Alesis ADAT BRC Service Manual
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Alesis ADAT BRC Service Manual

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BRC SERVICE MANUAL
January 1, 1994
Revision 2.00

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Summary of Contents for Alesis ADAT BRC

  • Page 1 BRC SERVICE MANUAL January 1, 1994 Revision 2.00...

  • Page 2: Warnings

    ALL REPAIRS DONE BY ANY ENTITY OTHER THAN AN AUTHORIZED ALESIS SERVICE CENTER SHALL BE SOLELY THE RESPONSIBILITY OF THAT ENTITY, AND ALESIS SHALL HAVE NO LIABILITY TO THAT ENTITY OR TO ANY OTHER PARTY FOR ANY REPAIRS BY THAT ENTITY.

  • Page 3: Safety Suggestions

    SAFETY SUGGESTIONS Carefully read the applicable items of the operating instructions and these safety suggestions before using this product. Use extra care to follow the warnings written on the product itself and in the operating instructions. Keep the operating instructions and safety suggestions for reference in the future. 1.

  • Page 4: Document Revisions

    DOCUMENT REVISIONS Revision 1 4/5/93 Original Issue Revision 1.02a 6/3/93 Added information pertaining to troubleshooting as well as additional hardware modifications to the Main PCB. Revision 1.04 8/6/93 Added further information pertaining to troubleshooting as well as additional hardware modifications to the Main PCB.

  • Page 5: Table Of Contents

    TABLE OF CONTENTS PREFACE......................i WARNINGS ......................i SAFETY SUGGESTIONS ................. ii DOCUMENT REVISIONS................iii TABLE OF CONTENTS ................... iv LIST OF FIGURES .................... vi LIST OF TABLES ....................vi 1.0 INTRODUCTION..................1 1.1 Scope......................1 1.1.1 Document Conventions ..............1 1.2 BRC Reference Manual.................1 1.3 BRC Error Messages ..................1 1.4 BRC Sync Cable Requirements..............2 1.5 List Of Abbreviations ..................2...
  • Page 6 4.1 BRC Initialization..................15 4.2 BRC Self Test Routines.................15 4.3 QC Test Procedure..................17 5.0 BRC SYSTEM EXCLUSIVE INFORMATION ........18 5.1 Alesis BRC System Exclusive...............18 5.1.1 Opcodes ..................18 5.1.2 Global Parameter Edit Commands ..........18 5.1.3 Song Parameter Edit Commands ............20 5.1.4 Action Commands ................23 5.2 MIDI Machine Control Commands...............25...
  • Page 7 LIST OF FIGURES Figure 3-1 - BRC Assembly and Disassembly ............7 Figure 3-2 - Diode Orientation Within the BRC ..........9 Figure 3-3 - LED Orientation Within the BRC ...........9 Figure 3-4 - Pinout Diagram of EPROM Chip (U9) ...........12 Figure 3-5 - Pinout Diagram of Processor Chip (U10) ........13 Figure 3-6 - Pinout Diagram of FPGA Chip (U11)..........14 Figure B-1 - BRC Main PCB Jumpers ..............B-3 Figure E-1 - BRC QC Test Connection Diagram..........E-15...

  • Page 8: Introduction

    (such as PLAY or REWIND). 1.2 BRC Reference Manual The BRC Reference Manual (Alesis P/N 7-51-1066) is included with every BRC sold. This manual explains the basic operation, features, and applications of the BRC. The manual contains diagrams of both the BRC front panel controls and the rear panel interface. Moreover, the manual contains several connection diagrams for a variety of recording situations.

  • Page 9: Brc Sync Cable Requirements

    The wire gauge of these new sync cables is 24 AWG. To determine which type of sync cable is the correct one, look at the cable's 9 pin connectors. If the word "Alesis" is stamped on each side of both connectors, then it is of the correct variety.

  • Page 10: Brc Building Blocks

    Appendix A. However, there are no serviceable parts within this supply. Alesis purchases this supply off-the-shelf from an outside vendor. If there is a problem with the power supply, It is usually less time consuming to replace the whole power supply.

  • Page 11: 10 Mhz Timer

    The 4053's in the VCO are used to lock the VCO to internal and external clock sources, thus syncing all the other clocks. With the FPGA affecting the timing of the signal SLAVECLK (one of the 4053's controls) and with the H8/534 microprocessor affecting the signal FAST/SLOW (the other 4053's control), the timing of the signal PCOUT, which pulses the gate of the FET, can be affected.

  • Page 12: Video Interface

    2.3.5 Video Interface Video synchronization is achieved through BNC connector J13. The signal fed into the BRC from this connector is called VIDEO IN. This signal then feeds a circuit which is used to extract a vertical sync signal. The output of this circuit is the signal VIDEO, which then is fed into the FPGA at pin 29.

  • Page 13: Brc Repair

    BRC, refer to figure 3-1 for a pictorial representation of the text that follows. Note that prior to opening the BRC, you may first have to remove the Alesis Remote Meter Bridge (RMB) which attaches to the BRC via 4 screws. These screws are located on the sides of the BRC and are used to fasten a sheet metal piece from the RMB to the BRC.

  • Page 14: Figure 3-1 - Brc Assembly And Disassembly

    Figure 3-1 - BRC Assembly and Disassembly...

  • Page 15: Brc Internal Cabling

    3.3 BRC Internal Cabling All the of the PCBs connect to the Main PCB with ribbon cables. The number of wires in each cable depends on the PCB. For all ribbon cables except the one which connect the LCD PCB to the Main PCB, the red striped wire corresponds to pin 1 of the associated connector.

  • Page 16: Front Panel Pcb Switches

    The switches are arrayed in a 14 column x 8 row matrix. In a similar manner to the method described for the LEDs, the processor uses U5 and U7 (both HC574 flip flops) to scan each of the columns for a depressed switch by pulling a low on one column at a time. When a switch is pressed in a column that is low, it creates a current on that specific row, causing that row (normally high) to pull low.
  • Page 17 During the course of development of the BRC, Alesis has found two types of symptoms which indicate specific problems. These are listed below: 1. Basic functions are not working properly: In this scenario, the first things that should be checked are the voltage of the battery and the voltage at U8, pin 32. Check both of these voltages with power off.

  • Page 18: Vco Circuit Troubleshooting

    For BRCs that intermittently reset, there is no concrete solution other than replacing the power supply. However, this solution does not always work. If you have a unit which is exhibiting this symptom and it cannot be resolved with a new power supply, contact Alesis Product Support so that this unit can be replaced.

  • Page 19: Figure 3-4 - Pinout Diagram Of Eprom Chip (U9)

    TABLE 3.2 - SOFTWARE COMPATIBILITY CHART Software Revision EPROM (U9) FPGA (U10) Processor (U11) 1.00 27C512 Rev 0 (1.00) 1.00 1.01 27C512 Rev 1 (1.01) 1.00 1.02 27C512 Rev 2 (1.02) 1.01 1.03 27C010 Rev 2 (1.02) 1.01 1.04 27C010 Rev 3 1.02 FPGA Version 1.02 adds a one-shot to the video input circuit to filter out possible...

  • Page 20: Figure 3-6 - Pinout Diagram Of Fpga Chip (U11)

    Figure 3-6 - Pinout Diagram of FPGA Chip (U11)

  • Page 22: Brc Testing

    4.0 BRC TESTING Every BRC under repair must be fully tested prior to its shipment back to the customer. Appendix E contains the test procedure which should be conducted on every BRC serviced. Furthermore, within the BRC software are a number of self test routines which can be implemented to aid in determining various problems with the unit.

  • Page 23: Table 4.1 - Brc Self Tests

    TABLE 4.1 - BRC SELF TESTS Test No. Test Name Description of Test ROM Test Tests BRC ROM integrity. If this test passes, the LCD will display PASSED and it will exit this test automatically. However, if the unit fails this test, the LCD will display FAILED and won't exit the test until the operator presses both PITCH and PITCH...

  • Page 24: Qc Test Procedure

    TABLE 4.1 - BRC SELF TESTS (Cont'd) Test No. Test Name Description of Test 48 KHz In/Out Tests BRC 48 KHz functionality. To conduct this test, the operator must connect a BNC cable from the 48 KHZ input jack to the 48 KHZ output jack on the back of the BRC.

  • Page 25: Brc System Exclusive Information

    5.1 Alesis BRC System Exclusive In addition to MIDI Machine Control (MMC) commands, the BRC also responds to and sends out Alesis system exclusive commands to access functions that are not addressed by MMC commands. The BRC has the following MIDI System Exclusive format:...
  • Page 26 <data> - 0..200 (0..C8H) cents represented as 2 bytes* 0000000a 0bbbbbbb a=bit7, 0bbbbbbb=bit6..0 * Pre/post-roll time is in tenths of a second (range = 0.0 to 20.0 seconds) Display Type <data> - 0000bsna (b=bars, s=SMPTE, n=normal, a=absolute/relative) SMPTE Type <data> - 0=24 fps, 1=25 fps, 2=29.97 fps, 3=29.97DF, 4=30 fps, 5=30DF AI-1 Dest/Clock <data>...

  • Page 27: Song Parameter Edit Commands

    Options <data> - 0 gfedcba a = Group Buttons 0=enabled, 1=disabled b = CopyTape 0=norm, 1=copy to L00 c = Tape Error 0=enabled, 1=disabled d = Rew/FF SMPTE output 0=enabled, 1=disabled e = Sysex output (exclude dump) 0=enabled, 1=disabled fg = 000 Manual Locate Address <data>...
  • Page 28 <data> - <timecode> <timecode> - 32-bit timecode transferred as 5 bytes (a=msb, d=lsb) a7 a6 a5 a4 a3 a2 a1 a0 transfer as 00 a6 a5 a4 a3 a2 a1 a0 b7 b6 b5 b4 b3 b2 b1 b0 00 b5 b4 b3 b2 b1 b0 a7 c7 c6 c5 c4 c3 c2 c1 c0 00 c4 c3 c2 c1 c0 b7 b6 d7 d6 d5 d4 d3 d2 d1 d0...

  • Page 29: Action Commands

    Loop End Locate Num <data> - 1..22 Group <sub-param> = group number (0..3) <data> - <track bitmap> <track bitmap> -MMC track status format Tape Offset by Time <sub-param> - machine number (0..15) <data> - <timecode> <timecode> - 32-bit timecode transferred as 5 bytes (a=msb, d=lsb) a7 a6 a5 a4 a3 a2 a1 a0 transfer as 00 a6 a5 a4 a3 a2 a1 a0 b7 b6 b5 b4 b3 b2 b1 b0 00 b5 b4 b3 b2 b1 b0 a7...
  • Page 30 <data> - 0..3 59H - Recall Group F0H 00H 00H 0EH 09H <dev#> 59H <group#> F7H <group#> - 0..3 5AH - Select Song F0H 00H 00H 0EH 09H <dev#> 5AH <song#> F7H <song#> - 1..20 5BH - Locate Song F0H 00H 00H 0EH 09H <dev#> 5BH F7H 5CH - Copy Tape Location (simulates CopyTapeLoc button press) F0H 00H 00H 0EH 09H <dev#>...
  • Page 31 01H - MIDI Dump (All songs, global, tempo map)** F0H 00H 00H 0EH 09H <dev#> 01H <type> <size> <data> F7H <type> - 0 thru 19=song, 20=global, 21=tempo map <byte count> - <countH> <countL> <countH> - 0xxxxxxx (xxxxxxx=count<7..13>) <countL> - 0yyyyyyy (yyyyyyy=count<0..6>) where global count = B0H = 01H 30H tempo count = 2AEH = 05H 2EH song count = 32CH = 06H 2CH...

  • Page 32: Midi Machine Control Commands

    5.2 MIDI Machine Control Commands Whenever possible, a MMC command is used for ADAT operation in order to maintain a maximum of compatibility with MMC devices. For specific information on the use of MMC commands, please refer to the MIDI 1.0 Recommended Practice RP-103 document, available from the IMA. MIDI Machine Control (MMC) Format: F0 7F Universal System Exclusive Real Time header Destination...

  • Page 33: Universal System Exclusive Midi Inquiry Message

    F0 7E <channel> Universal System Exclusive Non-realtime header General Information (sub-ID #1) Device Id Message (sub-ID #2) 00 00 0E Alesis manufacturer ID 09 00 Device family code (LSB first) 00 00 Device family member code (LSB first) v0 v1...

  • Page 34: Brc Schematics

    APPENDIX A BRC SCHEMATICS...

  • Page 35: Brc Hardware Upgrades

    APPENDIX B BRC HARDWARE UPGRADES...

  • Page 36: Brc Main Pcb Upgrades

    BRC Main PCB Upgrades For all BRC main PCB's dated 11-5-92 (Revision 1), the following hardware modifications are required: 1. Add a 470 µF electrolytic capacitor, 6.3 V minimum, across C56 with the + side connected to +5V. This provides better supply filtering for the VCO, which reduces jitter. 2.

  • Page 37: Figure B-1 - Brc Main Pcb Jumpers

    Figure B-1 - BRC Main PCB Jumpers...

  • Page 38: Power Supply Insulator Sheet

    Power Supply Insulator Sheet In order to prevent accidental short circuiting of the BRC power supply with the BRC chassis, an insulator sheet has been added underneath the power supply, between the power supply and the screw terminals on the bottom panel. For all BRCs serviced, verify that this insulator sheet is installed.

  • Page 39: Brc Software History

    APPENDIX C BRC SOFTWARE HISTORY...

  • Page 40: Version 1.00

    General Notes: 1. Every time there is a processor change, there must be an EPROM update, if only to modify the vector that points to the new processor code. 2. Consult Table 3.1 of this service manual for information on the software compatibility between the various version of software within the BRC.

  • Page 41: Version 1.02

    Version 1.02 Date of Release: 04/28/93 Checksum (Processor: int=64EB; ext=643C - REV2) (EPROM: int=78FD; ext=7874) NOTE: This software coincides with a hardware change to the SMPTE input circuitry. Refer to Appendix B for details. A. Processor Fixes: 1. Generation of MTC 29.97 non-drop and drop corrected. 2.

  • Page 42: Version 1.03

    Version 1.03 Date of Release: 05/04/93 Checksum (Processor: int=64EB; ext=643C - REV2) (EPROM: int=42D2; ext=41E8) NOTE: This software coincides with an EPROM size change from 27C512 to 27C010A A. EPROM Fixes: 1. If externally synced to SMPTE drop frame, then if the SMPTE input hour was greater than the SMPTE Start hour, external sync was lost each minute.
  • Page 43 D. EPROM Changes/additions: 1. Allow Auto Input, All Safe, and All Input when editing track delays. 2. SMPTE Start Offset: Prevent user from selecting invalid start times when SMPTE drop frame is selected. 3. External Clock: Increase external video out-of-range tolerance and improve external 48K out-of-range sensing 4.
  • Page 44 18. When performing a power-on reset, the display now reads "Initialization in progress." 19. If ADATs are stopped and the tape offset is changed (i.e. whenever tape offset is toggled on/off or whenever a tape offset value is changed while tape offset is enabled), a locate command is sent to all ADATs to position them correctly.

  • Page 45: Brc Parts List

    APPENDIX D BRC PARTS LIST...
  • Page 46 Confidential - Property of Alesis Corporation GROUP PART No. DESCRIPTION POSITION NOTES 9-96-1126 ASSY, BR PCB F/P LEFT 9-96-1127 ASSY, BR PCB MAIN PR 9-96-1128 ASSY, BR PCB KEYPAD 9-96-1129 ASSY, BR PCB F/P RIGHT 9-96-1130 ASSY, BR PCB SWITCH...
  • Page 47 Confidential - Property of Alesis Corporation GROUP PART No. DESCRIPTION POSITION NOTES 2-14-0541 IC 74HC541 OCTAL BUFFER TE MAIN 2-14-0574 IC 74HC574 OCTAL FF TEXAS MAIN U1-U5, U7 2-14-7403 IC 74HCU04 HEX INVERTER TE MAIN 2-14-7404 IC 74HC04 HEX INVERTER TEX...
  • Page 48 Confidential - Property of Alesis Corporation GROUP PART No. DESCRIPTION POSITION NOTES 9-15-1065 BUTTON WITH LIGHT PIPE 9-15-1067 PANEL, SIDE BR 9-15-1068 PANEL, TOP/BOTTOM 9-96-1200 ASSY TRACK SELECT BEZEL BR 0-00-0101 RES 100 OHM 1/8W 5% MAIN R49-R61,R65,R66,R70-R77 0-00-0102 RES 1K OHM 1/8W 5%...

  • Page 49: Brc Qc Test Procedure

    Confidential - Property of Alesis Corporation APPENDIX E BRC QC TEST PROCEDURE...

  • Page 50: Equipment Requirements

    Confidential - Property of Alesis Corporation BRC QC TEST PROCEDURE This test will verify the proper operation of the BRC within a studio configuration. This test should be performed on every BRC serviced. Furthermore, this test should be conducted only after all modifications and/or repairs on the unit have been completed (See Appendix B).

  • Page 51: Brc Connections And Setup

    Confidential - Property of Alesis Corporation 3.0 BRC Connections and Setup This step will setup the BRC for the tests to follow as well as detailing those connections which must be made to conduct said tests. Refer to figure E-1 for a block diagram of the connections required for this test.
  • Page 52 Confidential - Property of Alesis Corporation In 21 "PunchIn " 00:00:00 3.1.12. Use the CURSOR buttons to move the cursor under the display of zeros on the LCD. 3.1.13. Use the keypad's numeric buttons to enter a new Punch In point. Note: The Punch In point selected here has to be different from the Punch In point entered for the previous BRC under test.

  • Page 53: Brc Self Tests

    Confidential - Property of Alesis Corporation 3.2.6. Connect the ADAT Sync cable from the BRCs REMOTE OUT TO ADAT connector to the ADATs Sync In connector. 4.0 BRC Self Tests This test will verify the proper operation of all BRC interfaces as well as the BRC software, LEDs and switches.
  • Page 54 Confidential - Property of Alesis Corporation 4.4.1. Press KEYPAD NUMBER 3. 4.4.2. Verify that the LCD displays the message Select Test 3: LEDS (cycle) 4.4.3. If this message is not displayed, repeat step 4.4.1 until the appropriate message is displayed.
  • Page 55 Confidential - Property of Alesis Corporation 4.6.5. Verify that the LCD displays the message LCD TEST Footswitch1: 01 4.6.6. Press each button on the LRC. 4.6.7. For every button pressed, verify that the LCD displays a corresponding number next to the line reading "Footswitch1:". For example, pressing the PLAY button on the LRC will cause the LCD to display "Footswitch1: 06"...
  • Page 56 Confidential - Property of Alesis Corporation 4.8. 48 KHZ Interface Test 4.8.1. Press KEYPAD NUMBER 7. 4.8.2. Verify that the LCD displays the message Select Test 7: 48K IN/OUT 4.8.3. If this message is not displayed, repeat step 4.8.1 until the appropriate message is displayed.

  • Page 57: Save Setup To Tape Test

    Confidential - Property of Alesis Corporation 4.10.7. If the LED does not display running time code, then the BRC has failed its SMPTE interface test. 4.10.8. Press PITCH and PITCH simultaneously. Verify that the LCD displays the message shown in step 4.10.2.

  • Page 58: Load Setup From Tape Test

    Confidential - Property of Alesis Corporation 6.0 Load Setup from Tape Test This test will verify that the BRC successfully loads the BRC setup which was just saved to the ADAT tape in step 5.0. 6.1. Press the LOAD SETUP FROM TAPE button.

  • Page 59: Brc Auto Punch Test

    Confidential - Property of Alesis Corporation 7.10. Press POST-ROLL. Verify that its LED illuminates. 7.11. When the BRC LED counter displays the time input in step 3.1.26, verify that the BRC goes into Rewind mode and then into Play mode when it reaches the time input in step 3.1.25.

  • Page 60: Additional Test Requirements

    Confidential - Property of Alesis Corporation PART 2 These tests require the use of 2 ADATs and therefore are optional tests. However, if 2 ADATs are available, these tests must be conducted. 9.0 Additional Test Requirements In order to conduct all of tests described herein, the following additional equipment, connections and setup is required.

  • Page 61: Digital I/O Test

    Confidential - Property of Alesis Corporation 9.3.12. Use the CURSOR buttons to move the cursor under the display of zeros on the LCD. 9.3.13. Use the keypad's numeric buttons to enter a new Offset point. Note: The Offset point selected here has to be different from the Offset point entered for the previous BRC under test.

  • Page 62: Tape Offset Test

    Confidential - Property of Alesis Corporation 10.17. Press STOP once the PLAY light stops flashing. 10.18. Press TRACK 1 RECORD READY. Verify that its corresponding LEDs are not lit. 10.19. Press TRACK 2 RECORD READY. Verify that its corresponding LEDs are not lit.

  • Page 63: Figure E-1 - Brc Qc Test Connection Diagram

    Confidential - Property of Alesis Corporation Figure E-1 - BRC QC Test Connection Diagram E-15...
  • Page 64 Confidential - Property of Alesis Corporation BRC REPAIR SHEET Rev -12/22/93 JWS UNIT S/N: BR22 MFG DATE: [ DATE REPAIRED: [ RA NUMBER: SERVICE TECH: S/W RECEIVED: S/W INSTALLED: LABOR HRS: UPDATES (Check for each unit serviced) MAIN PCB HARDWARE MODS: INSTALLED _____ REQUIRED _____...

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