Brother DP-525CJ - Page 4

SERVICE MANUAL
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10.3.1. Read/Write Circuit...................................................................................... 2-26
10.3.2. Motor Drive Circuit...................................................................................... 2-26
10.3.3. Sensor Circuits ........................................................................................... 2-26
PART II REPAIR
CHAPTER 3 TROUBLESHOOTING .......................................................................... 3-1
1. Introduction .............................................................................................................. 3-1
2. Precautions .............................................................................................................. 3-1
2.1. Personal Safety.......................................................................................................... 3-1
2.2. Handling ESD-Sensitive Parts.................................................................................... 3-1
3. Checks Before Repair .............................................................................................. 3-2
4. Checks After Repair ................................................................................................. 3-3
5. Troubleshooting Flow Charts.................................................................................... 3-4
6. Failure Analysis........................................................................................................ 3-6
7. SELF-TESTS.......................................................................................................... 3-13
7.1. SERIAL NUMBER Input Display............................................................................... 3-13
7.2. Self Print Mode......................................................................................................... 3-14
7.3. Self-Test Mode......................................................................................................... 3-17
7.3.1. Display (CRT) Test..................................................................................... 3-19
7.3.1.1. Cross Hatch Pattern Test...................................................................... 3-20
7.3.1.2. Full Dot Screen Test............................................................................. 3-21
7.3.1.3. Blank Screen Test ................................................................................ 3-22
7.3.1.4. H Pattern Test ...................................................................................... 3-23
7.3.1.5. mw Pattern Test.................................................................................... 3-24
7.3.1.6. Dot Pattern Test.................................................................................... 3-25
7.3.2. Print Checks............................................................................................... 3-26
7.3.2.1. Print Test Pattern 1............................................................................... 3-26
7.3.2.2. Print Test Pattern 2............................................................................... 3-29
7.3.2.3. Dot Patterns.......................................................................................... 3-31
7.3.3. Keyboard Tests........................................................................................... 3-33
7.3.4. FDD Tests .................................................................................................. 3-36
7.3.4.1. FDD Test.............................................................................................. 3-36
7.3.4.2. Special FDD Test.................................................................................. 3-37
7.3.4.3. FDD SW Test ....................................................................................... 3-41
7.3.4.4. FDD Write Error Rate Check ................................................................ 3-42
7.3.4.5. FDD Read Error Rate Check................................................................. 3-44
7.3.5. PE (Paper-End) Sensor Test....................................................................... 3-46
7.3.6. CR (Carriage Reset) Test ........................................................................... 3-47