Sharp ER-04RP Service Manual page 11

ER-04RP
3. Adjust the VR1 5~ potentiometer to obtain the fOi10win9
waveform.
w
T1 : 580nsec-620nsec
0.61Js 0.41.Is
T2: 380nsec-420nsec
Fig. 5-13
4. Power supply circuit
1)
2)
Power supply circuit (secondary side)
This power supply circuit supplies the logic drive power of
5VDC, the printer mechanism drive power of 24VDC, and the
SRN interface bias circuit drive power of 12VDC. CN2 is con-
nected to the printer control PWB, and CN3 to the SRN inter-
face PWB.
ICI is a regulator IC of low saturation voltage type which sup-
plies stabilized +5V power to the circuits.
The 24V power is stabilized by IC2 with the current boosted by
transistor Q1.
The +12V power is created from the 24V power using IC3.
The fuse is T1A250V, and protects the 5V power from overcur-
rent.
Noise filter circuit (primary side)
The noise filter circuit uses a common mode type filter to
eliminate noise generated from the AC power supply as well as
radiation noise from the printer and thus assure stable opera-
tion of the printer.
....... .
N 4
T
-N
"
1
~c3222
ACIN
cl — ; \ C2
h
ACOUT
IMT ; : T104 C4 ,
PlA~21A
Fig. 5-14
6. Printer unit description
6-1. Hints and tips in handling the printer
6-1-1. Hints in using the printer
(1)
(2)
(3)
(4)
Do not operate the printer when the printer is not loaded with
paper and ink ribbon. Printing without paper or ink ribbon will
damage the printhead and platen surface, deteriorate the print
quality, and shorten the printer life.
Do not try to move the print head by hand. Since the belt that
drives the print head is directly coupled with a gear train, the belt
and the carriage drive pipe will be subjected to overioad when
the print head is moved by hand, leading to timing misalignment
and other trouble.
Since the printer uses a permanent magnet (in the motor) and
an electromagnet, avoid using the printer in a location that may
be subjected to a large amount of iron filings, dust, dirt, etc.
Printed circuit boards are mounted in the bottom of the printer.
Take care so that the printed circuit boards do not come in
contact with the case or foreign materials do not adhere to the
boards.
6-1-2. Hints in storing the printer
(1)
Do not store the printer in a location where a large amount of
dust or dirt, high temperature, or high humidity is encountered.
6-2. How to load the paper
Use paper of prescribed standard.
6-2-1. Paper lead edge finish
Cut the paper lead edge straight. (See figure below)
If the paper cannot be smoothly taken up by the paper feed roller, fold
back the paper lead edge for ease of insertion.
o
x
rlr
6-2-2. How to load the roll paper
Load the paper as shown below.
Correct
o
Incorect
x
- —
6-2-3. How to load the sprocket paper
Pull the knob outward and manually rotate the sprocket to load the
paper. With the knob pulled outward, the sprocket can be freely
rotated.
6-2-4. How to remove the paper from the printer
The paper can be removed from the printer in any of the following
methods.
(1)
(2)
(3)
Pull out the paper upward. (For friction type only)
NOTE: Paper must be pulled straight upward. If pulled slanting-
ly, the paper may become jammed in the Printer.
o
If the printer is provided with a paper feed knob, pull the knob to
release the shaft, and rotate the shaft to eject the paper. (In this
case, the paper can be ejected in either direction)
Eject the paper by electrically operating the printer (pressing the
paper feed button with the power ON).
6-3. Hints in using the ribbon cartridge
Use the ribbon cartridge of prescribed specification. If a non-specified
ribbon cartridge is used, problems may arise such as malfunctioning
of the wire, deterioration of print quality, etc.
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