Troubleshooting Problems - Canon S520 Service Manual

S900 / S820 / S750 / S520

2.3 Troubleshooting Problems

Problem
Power does not turn on.
After power ON, it
immediately turns off
again.
The print head is not
recognized. It does not
return to the home
position.
Abnormal noise
Printing stops midway.
Multiple sheets are fed
at a time.
Paper is not fed.
Paper is fed skewed.
No printing.
No color.
Scrape marks or white
stripes appear even after
cleaning.
Lines not in the printing
data appear.
The paper is stained.
Spur marks appear.
Lines are missing.
Inappropriate color tones.
Overlapping printing.
No black.
Images / text appears
stretched.
Probable Cause / Check Items
1. AC adapter, 2. Logic board
1. Print head, 2. Print head
contacts, 3. Carriage flex cable
1. Dislodged parts, 2. Dislodged
pinch roller
1. Logic board
1. ASF (Return tab, faulty
pressure roller operation)
1. Foreign matter, 3. PE sensor
arm
1. Paper guide, 2. Foreign matter
adhering to paper feed rollers
1. Print head, 2. Ink tanks, 3.
Purge unit
1. Print head, 2. Ink tanks, 3.
Purge unit, 4. Print head
contacts, 5. Carriage flex cable
1. Ink mist from the paper
transport section in the printer,
2. The ink absorber (platen) is
dirty.
1. Deformed spur tips.
1. Ink tanks.
1. Print head.
1. Platen unit (eject roller)
1. Ink tank.
1. Timing slit strip.
2-9
Part 2: Troubleshooting
Solution
1. Replace faulty parts.
1. Remove and reinstall
print head / check the
contacts, 2. Replace faulty
parts.
1. Remove foreign matter,
2. Reinstall dislodged
parts
1. Replace faulty parts.
1. Replace faulty parts.
1. Remove foreign matter,
2. Replace faulty parts, 3.
Replace ASF unit
1. Adjust the paper guide
to the correct position, 2.
Remove foreign matter.
1. Replace faulty parts.
1. Remove and reinstall
print head / check the
contacts, 2. Replace faulty
parts.
1. Feed through several
sheets of clean paper, 2.
Replace the ink absorber
(platen), 3. Purge unit.
1. Replace faulty parts.
1. Replace ink tanks.
1. Replace faulty parts.
1. Replace faulty parts.
1. Perform Deep
Cleaning (3 times)
1. Clean grease from
timing slit strip,
2. Replace the carriage
board.