Replacement of mechanical and electronic parts of LG 6721RFN021A with GH22NP20 parts with GH22NP20 parts This type of operation will be useful for all owners of LG DVD recorder of the family RH177 / RH188 / RH198 who encounter problems of reliability of reading and burning with the rewriter 6721RFN021A. Indeed the small footprint of the 6721RFN021A not allows its replacement directly by the GH22NP20. Be a little bit patient and meticulous and you will be able to make it. Nothing is insurmountable for a good handyman! 1
Transcript
Replacement of mechanical and
electronic parts of LG 6721RFN021A
with GH22NP20 partswith GH22NP20 parts
This type of operation will be useful for all owners of LG DVD recorder of the family RH177 / RH188 / RH198
who encounter problems of reliability of reading and burning with the rewriter 6721RFN021A.
Indeed the small footprint of the 6721RFN021A not allows its replacement directly by the GH22NP20.
Be a little bit patient and meticulous and you will be able to make it.
Nothing is insurmountable for a good handyman!
1
Check of functioning of GH22NP20
Before opening the GH22NP20 ensure it works properly on your recorder because once opened
the warranty will not be ensured !
To do this check remove the rewriter by unscrewing the 4 screws, unplug the power cable and
IDE cable (it’s stuck with a double-sided adhesive under the rewriter).
Plug the GH22NP20 as shown in the picture.
Original rewriter Check of GH22NP20 2
Remove all parts of 6721RFN021A
If you are sure that the GH22NP20 is working properly you can start to disassemble the old parts of
the 6721RFN021A.
Disassembly of old parts
1 2 3
Unscrew the 4 screws. Unscrew the 2 screws.
Unplug the 2 ribbon cables
on the printed circuit.
Remove the 2 metal covers.
4 5 6
Lift up the black mechanical lock and
unplug the optical ribbon cable.
Unclip the printed circuit and
unplug the 3rd ribbon cable
on the left side.
Remove all parts of 6721RFN021A
In order to continue to remove the parts you have to move the gear in front of the rewriter to open the loader.
7 8 9
Unlock the loader by
moving the wheel.
Remove the belt. Remove the motor of loader
by acting on the 4 clips.
At this time all electronics
parts are removed .
Remove the optical mechanism by
unscrewing the 2 screws and slide
the 2 silent blocks.
10
At this time the optical
mechanism is removed .
Remove all parts of 6721RFN021A
It’s done ! You have disassembled all parts.
All these parts will not be useful for the following.
You can keep them for memories or put them into
garbage can.
Frame , screws for optical mechanism and metal
covers must be kept for final reassembly.
5
Remove all parts of GH22NP20
All electronics and mechanical parts (except metal covers) will be used for the final reassembly.
It’s why it’s very important to remove them carefully.
Disassembly of new parts
1 2 3
Unscrew the 4 screws. Remove the metal cover. Unlock the loader and open it
with a paper clip.
Push the 2 clips on each side to
remove the front and pull out
the frame.
4
Lift up the black mechanical lock and
unplug the optical ribbon cable.
5
Unplug the 2 front ribbon cables,
lift up the printed circuit and
unplug the 3rd ribbon cable.
6
Remove all parts of GH22NP20
7 8
At this time the printed
circuit is removed .
Remove the belt. Remove the motor of loader
by acting on the 3 clips.
Remove the optical mechanism by
unscrewing the 2 screws and slide
the 2 silent blocks.
9
7
Remove all parts of GH22NP20
It’s done ! You have disassembled all parts you need .
This frame and the metal covers will not be useful for
the following. You can keep them for memories or put
them into garbage can.
All these parts must be kept for final reassembly.
8
Modifications before reassembly
The frame must be modified to avoid the blocking of the new optical mechanism.
Use a flat file to suppress some plastic parts on the support.
It’s recommended to protect the mechanism with an adhesive paper during the operation and to clean it after.
Modification of support of optical mechanism
Before modification
9
After modification
Modifications before reassembly
The small printed circuit of the loader must be modified in order to be able to put the metalic cover.
Use a flat file to reduce the width about 1.5 mm . Clean the printed circuit when it’s done.
The LED must be removed.
Modification of printed circuit for loader motor
Before modification After modification LED removed
10
Reassembly
Did you sort all part you need ?
Final reassembly
1 32
Bend the clip not used for the
new printed circuit board.
Insert the printed circuit
board by using the 3 clips.
Unlock the loader by
moving the wheel.
Put the optical mechanism by sliding
the silent blocs with a small screwdriver
in the centre then screw the 2 screws.
Plug the 3 ribbon cables and insert
the printed circuit by using the clip
then plug the optical ribbon cable .
Put the belt.
654
11
Reassembly
7
Check if the loader can be locked
without force by moving the
mechanism to the left.
Take the 2 thermal pads from
the cover of the GH22NP20.
Sticks the 2 thermal pad
on these components
8 9
It’s very important to have a good thermal contact between these 2 components and the metal cover.
It’s why you have to intercalate a metalic plate . See below to make it.
aluminium plate
10<
²25
37 8 17
516
8
20 735
Aluminium sheet thickness 1mm
Dimensions in mm
Tolerances +- 0.5 mm
2 holes diameter 3mm
12
<
Reassembly
11
Put the plate in the angle of the
metal cover and drill 2 holes
then screw or rivet the plate.
! File the screws or the rivets in
order to avoid electrical contact
with the printed circuit.
12
When all is OK you can reassemble
the 2 metal covers.
13
then screw or rivet the plate. with the printed circuit.
Risk of short circuit !
Finally it’s finish!
Now you can replace the rewriter in your DVD recorder.
Plug the IDE ribbon cable and don’t forget to stick it under the rewriter then screw it.
