2025-05-16 - Partially Fixing a JVC XV-NP1SL DVD Player
-------------------------------------------------------

Someone gave me a defective JVC XV-NP1SL DVD player[0] a while ago.
The problem was that the tray refused to open when eject was pressed,
so it was impossible to insert a DVD. I have absolutely no use for
a standalone DVD player, and this one isn't even particularly good,
so naturally I decided to fix it anyways.

WARNING: This is a mains-connected device. Do not open such devices
if you do not know what you are doing as it can potentially cause
injury or even death.

WARNING: This device contains a laser that can damage your eyes if
you look at it while it is on. Do not open such a device if you do
not know how to protect yourself against these dangers. See [52]
for more warnings concerning lasers in optical drives.

Disassembly
-----------

There are five screws on the outside, one on each side and three at
the back. Once these have been unscrewed, the cover can be removed[1].
The cover was stuck on fairly tightly, so it was somewhat annoying to
get off. Inside, the DVD drive is held on by three screws[2] that
have to be unscrewed. There also is a ribbon cable connecting it to
the main circuit board[3]. This ribbon cable is of the type where
you have to pull up a plastic piece on the socket before the cable
can be removed. Usually, it would be possible to just take the drive
out now. The problem is that there is a silver plastic cover at the
front of the drive tray that doesn't fit through the opening in the
front panel. If the drive still opens, that plastic cover can just
be removed, but since the drive wasn't opening, it was stuck to the
front panel, so I had to remove that as well. There would have been
a better way to open the tray, but I only learned about that later.

On the right-hand side, a small circuit board is screwed to the front
panel[4] that can be unscrewed[5] (I guess I could have alternatively
just unplugged the ribbon cable and left the board screwed to the
front panel). There is also a screw on the right-hand side holding
the front panel to the rest of the DVD player[6], as well as a ribbon
cable on the left-hand side that needs to be unplugged[7]. Once the
clips on the bottom[8] and on the sides[9] are unclipped, the front
panel can be removed[10].

In order to get to the mechanism, the circuit board on the bottom of
the DVD drive[11] has to be removed[12]. The laser assembly can then be
unscrewed and removed[13]. In the remaining part of the drive, there
is a plastic part that can be pushed out of the holes it is clipped
into[14] in order to remove it[15]. Once that is done, a white plastic
plate becomes accessible[16]. This plate moves sideways as the tray
opens and closes. This can be moved manually, possibly while pulling
the tray in order to finally open the tray[17]. Note that since I am
writing this from memory, I don't remember entirely how the mechanism
worked, but it should be possible to open the tray by fiddling around
with it a bit. It is also possible to turn the gears manually, but they
aren't as easily accessible when the front panel is still attached.

Anyways, once the tray is open, the silver cover at the front can
simply be pushed off[18], after which the drive can be removed from
the front panel[19]. It's a good idea to leave the cover off even
when reassembling until the DVD player is really fixed so the drive
can be removed more easily in the future (and the cover can easily be
pushed on later when the tray is open).

Greasing and Oiling
-------------------

I decided to first grease the mechanism and check if that would change
anything. The black plastic part that was removed first has several
parts sticking out that slide along grooves on the side and in the
white plate and should be greased[20]. The surface behind the white
plate should also be greased since the plate slides over it[21]
(yes, I know that the motor wires are already desoldered in this
picture, the pictures aren't entirely chronologically accurate). It
is also possible to remove the tray in order to access more of the
mechanism. On one side, there are screws holding it in place[22],
on the other side some force is required to bend the plastic out of
the way[23]. I tried to find a better way to remove the tray without
having to use as much force on the plastic, but I couldn't find
any. I did finally manage to remove the tray, though[24]. The gears
in the rest of the mechanism can be greased[25], although I really
don't know if that's necessary. On the tray itself, the metal bar
on one side should be greased[26]. As far as I could tell, the gear
teeth on the side weren't greased, so I don't think greasing those is
necessary. One important note here is that the plastic wheel on the
motor shaft shouldn't be pushed in too far. I first thought that it
had been pulled out because it was only partly on the shaft, but when I
pushed it all the way in, the mechanism jammed because another plastic
piece moved into the wheel and prevented it from turning[27]. I'm not
sure why the mechanism is designed in such a weird way. Either the
wheel should have been pushed down completely and the other plastic
piece redesigned, or the motor shaft should have been longer.

Unfortunately, greasing the mechanism didn't change anything about the
behavior and the tray still didn't open when eject was pressed. Some
online forums suggested that the belt might be slipping, but I checked
that and there definitely wasn't anything slipping. I decided to
take out the motor to test it ouside of the mechanism. It is held on
by two screws that first have to be unscrewed[28], before it can be
removed. The two wires also can be desoldered in order to test the
motor with an external power supply[29]. I placed it inside my
professional motor holder so I could run it from an external power
supply[30]. As with the CD player spindle motor a while ago[31],
I didn't notice anything unusual, the motor seemed to spin perfectly
normally. The motor was rated for 5.9V, but when I measured the voltage
that the DVD player was driving it with, that was around 1.84V. One
observation was that if I ran the motor from my external power supply
when it was connected to the mechanism, but used a slightly higher
voltage (I forgot what voltage exactly), the tray did come out. One
possible theory could be that something was wrong with the rest of the
DVD player and it simply wasn't driving the motor with a high enough
voltage, but considering my experience with the CD player spindle
motor, I'm more inclined to believe that the motor had just gotten
slightly weaker over the years. I did oil both the shaft and the
holes at the bottom a bit with sewing machine oil[32], and let the
motor run for a while to distribute the oil, but this didn't change
anything. Oiling the holes at the bottom probably wasn't a good idea
because then the oil can get to the brushes inside and maybe cause
even more issues.

Spindle Platter
---------------

I finally was led to the solution by two forum threads, [33] and
[34], which suggested that the issue was actually with the spindle
platter. When the tray is fully retracted, the spindle platter on the
motor at the bottom clamps against a platter at the top to hold the DVD
securely[35]. The platter on top can be unscrewed with a small screw on
top[36], after which the two parts can be separated. As can be seen in
[37], there is a round magnet inside which is what pulls the platter on
the spindle motor up against the top platter. Following a suggestion
in the forum threads, I tried to add a small gap between the magnet
and the bottom part to weaken the magnetic force pulling the bottom
platter up. I had some small plastic washers lying around, of which
I added three before screwing the top platter together again[38]. In
the picture, they're spread all over, but I did try to place them
more carefully around the center so they wouldn't cause the platter
to spin unevenly (although it would have been better to have different
washers that fit more exactly). Too many washers cause issues because
the two parts can't be screwed together properly anymore.

Once I put everything back together, the tray finally ejected
properly. There are some important notes I want to mention. Even before
adding the washers, I noticed that the tray would eject normally when
there was a DVD inside. This makes sense since the DVD also keeps the
two platters slightly apart (this was also mentioned in [34]). It also
was possible to get the tray to open by slightly pushing the spindle
tray down to separate it from the magnet as the tray was trying
to open. This would have been good to know in the beginning before I
took apart the entire mechanism just to separate the drive from the
front panel. Another note is that I first thought the tray still wasn't
ejecting properly, even after I had added the washers. This was because
I was running the mechanism from my external power supply, and I had
it upside-down for ease of access, which meant that the laser assembly
had to be pushed up against gravity by the motor instead of being
pulled down. Once I turned the mechanism around, everything worked.

The question remains what the exact reason for this problem was. Since,
as far as I know, it wouldn't make any sense for the magnet to become
stronger over time, I'm guessing the motor probably had gotten slightly
weaker, just as with the CD player I fixed previously. I did look for
this particular motor online, but I couldn't find the exact model for
reasonable prices, and I didn't want to spend too much time searching
for a compatible replacement. Since the tray ejecting was working
fine after my somewhat hacky fix, I decided to leave it at that.

Laser Assembly
--------------

The main problem was now fixed, but I noticed that there sometimes
was a clacking sound coming from the laser assembly right after
the tray had been pulled in[39]. DVDs would play normally afterwards,
but only after the clacking (although it sometimes worked without
any clacking). According to [40], this can often happen because the
limit switch that tells the laser assembly when it has reached the
edge is faulty.

I decided to first grease the laser assembly a bit. [41] shows the
gears with the brackets removed, [42] shows the disassembled state
(ignore the three washers in the picture, I'm pretty sure those were
left over from my experiments with different washers when I was trying
to fix the tray opening problem). Note that the metal bar at the bottom
of [43] wasn't greased in the first place, so I also didn't grease it
(if I remember correctly, there was also some sort of metal contact
from the moving part with the laser that was touching the bar, so
grease probably would have messed something up). I don't think any of
this greasing really was necessary because the old grease was still
fine, but I guess it didn't hurt.

[44] shows the switch that tells the laser when it has reached the
edge. To the left the plastic gear moving along the worm gear can be
seen. This is actually designed fairly well because the plastic gear
is attached in such a way that it can be pushed out of the way easily,
so when it skips teeth because it's trying to continue past the end,
it's just pushed out of the way instead of the teeth breaking (this
was the clacking sound I heard).

I measured the switch for continuity with a multimeter, and
everything seemed to be perfectly fine, but I still decided to open
it up anyways. In order to remove the circuit board the switch is
soldered to, the spindle motor has to be unscrewed[45]. This probably
was unnecessary, but it was convenient to have the circuit board
separated from the rest of the mechanism so the other parts weren't
in the way. Do note that the screws holding the spindle motor are
additionally fastened using some sort of thread locking compound. I
probably should have replaced that, but I didn't think of it at the
time (and I wouldn't have had any thread locking compound anyways),
so it's possible that the screws could become loose through vibrations
later.

The switch can be opened by first bending the parts of the metal
frame at the back to the side[46], then desoldering the sides of the
frame[47]. [48] shows the switch with the front part and the spring
inside removed. After cleaning the insides, the little spring has to
be placed inside again[49], after which the plastic part at the front
can be inserted and the metal frame placed around the switch[50]. This
part is very fiddly, and I had to try multiple times until I got
the spring in correctly and could place the plastic part on top
properly. It also is very easy to lose the spring because it is so
small. Don't forget to solder the sides of the frame and push the
parts at the back together again. All of this was entirely pointless
because the switch already worked before, and the clacking noise was
still there afterwards, but I guess it was kind of interesting to
see this type of switch from the inside. Perhaps there was still an
issue with the switch and it simply didn't turn on exactly at the
right position, but at this point, I really didn't want to spend any
more time debugging the device. Playing DVDs worked fine, and the
clacking shouldn't cause too much damage because of the way the
mechanism is constructed (as I showed earlier), so I think the DVD
player still is usable.

Weird Stuff
-----------

One last weirdness with this device was that there was a resistor
soldered onto the main circuit board that almost certainly didn't
originally belong there[51]. There were also other signs of previous
work around this area, so someone must have repaired something
previously. I spent some time trying to figure out what the reason
for the resistor was, but I couldn't figure it out (and I'd honestly
had enough of this device already). One theory is that it was used to
replace an SMD resistor that had gone bad. The two pads on the right
seem as if there used to be a component there, but the marking beside
them says "C451", so that would have been a capacitor. There were
also some components underneath the black double-sided foam tape the
resistor was stuck to, but I didn't want to remove it because it was
stuck on very tightly and I didn't want to accidentally rip off the
components underneath. I did see that there were at least two 0 Ohm
resistors underneath, but that was all I saw before deciding to leave
the foam tape alone. As can be seen in the picture, the right leg of
the resistor actually wasn't soldered on anymore. I experimented a bit
with the resistor connected and disconnected, but it didn't seem to
make any difference (I also tried that before fixing the tray ejecting,
so that definitely didn't have anything to do with it). In the end, I
just removed the resistor completely because everything seemed to work
without it, and it hadn't been connected anyways when I got the device.

UPDATE (2025-09-04): I don't know what I was thinking when doing this
repair. I've seen similar components in many older devices that were
definitely added in the factory, so it really isn't unusual to have a
resistor stuck on like that, even if it seems to be a bit weird. It
would have been better to solder the resistor on again instead of
removing it, but I guess at least everything seemed to work without it,
although there could have been some small difference that I just didn't
notice during testing.

One last note is that I also had issues with the ribbon cables getting
dirty. Once, the DVD player stopped reading DVDs completely, but that
went away after I cleaned the contacts on the ribbon cables.

Conclusion
----------

This repair wasn't entirely satisfactory because there was still
a problem remaining at the end, and the main fix was also sort of
hacky, not to mention the weird resistor whose purpose I still don't
understand. Still, it was possible to use the DVD player normally
in the end, so I guess it still was a successful repair. For me, it
was mainly interesting to see how the mechanism works since I don't
actually have any use for the DVD player myself.


[0] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/dvd_player.jpg
[1] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/open.jpg
[2] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/drive_screws.jpg
[3] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/drive_ribbon_cable.jpg
[4] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/front_panel_board1.jpg
[5] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/front_panel_board2.jpg
[6] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/front_panel_screw.jpg
[7] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/front_panel_ribbon_cable.jpg
[8] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/front_panel_clips1.jpg
[9] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/front_panel_clips2.jpg
[10] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/front_panel_removed.jpg
[11] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/drive_circuit_board.jpg
[12] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/drive_circuit_board_removed.jpg
[13] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/laser_assembly_removed.jpg
[14] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/drive_mechanism_disassembly1.jpg
[15] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/drive_mechanism_disassembly2.jpg
[16] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/white_plate.jpg
[17] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/drive_open.jpg
[18] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/drive_cover_removed.jpg
[19] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/drive_removed.jpg
[20] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/drive_greasing1.jpg
[21] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/drive_greasing2.jpg
[22] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/drive_greasing3.jpg
[23] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/drive_greasing4.jpg
[24] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/drive_greasing5.jpg
[25] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/drive_greasing6.jpg
[26] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/drive_greasing7.jpg
[27] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/mechanism_jammed.jpg
[28] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/motor_removal1.jpg
[29] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/motor_removal2.jpg
[30] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/motor_testing.jpg
[31] gopher://lumidify.org/0/phlog/2025-04-10-cd-player.txt
[32] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/motor_oiling.jpg
[33] https://www.badcaps.net/forum/general-topics/general-computer-tech-discussion/61225-lite-on-dvd-drive-eject-issue
[34] https://forums.tomshardware.com/threads/lite-on-dvd-writer-tray-will-only-eject-when-a-disc-is-in-tray.670215/
[35] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/spindle.jpg
[36] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/spindle_top_screw.jpg
[37] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/spindle_top_open.jpg
[38] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/spindle_top_washers.jpg
[39] gopher://lumidify.org/9/phlog/2025-05-16-dvd-player/clacking.ogv
[40] https://yesterware.blogspot.com/2020/10/what-ive-learned-fixing-optical-drives.html
[41] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/laser_assembly_greasing1.jpg
[42] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/laser_assembly_greasing2.jpg
[43] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/laser_assembly_greasing3.jpg
[44] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/laser_switch.jpg
[45] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/laser_switch_disassembly1.jpg
[46] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/laser_switch_disassembly2.jpg
[47] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/laser_switch_disassembly3.jpg
[48] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/laser_switch_disassembly4.jpg
[49] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/laser_switch_reassembly1.jpg
[50] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/laser_switch_reassembly2.jpg
[51] gopher://lumidify.org/I/phlog/2025-05-16-dvd-player/resistor.jpg
[52] https://www.repairfaq.org/sam/odfaq.htm#odsaf