Teardown: Philips BDP2180/79 3D Blu-ray Player with Stuck Tray

Around three or four years ago, coincident with my purchase of a 3D TV, I decided to buy a Blu-ray player. I decided to opt for a 3D capable unit, so as to have something to watch on the new TV. At the time, there were a few units, but the Philips BDP2180/79 was the cheapest at AU$89, which was pretty much the same price as most regular Blu-ray players.

Since the initial first few weeks, the unit’s not seen much action as watching things on a TV (centrally located) has fallen out of favour to watching video on a personal device (be it a phone, tablet or computer) and optical discs have also fallen out of favour compared to streaming.

I decided to try and watch something just yesterday, and to my annoyance, the tray would not eject. It would try to eject, making a half-clunk before stalling, timing out, and clunking again. This is a fairly common issue with almost all tray-loading optical drives, so I decided to use the opportunity to show the insides of the player as well as the components that make up the tray-load mechanism.

The Player

The player is a very compact unit, rather unassuming, light and flimsy but with a decent remote control that has “clicky” buttons. The unit has a USB port for playing files from as well as the optical drive.

As part of the cost reduction, it features only HDMI output, with coaxial for audio and LAN for data (including network media play, firmware upgrade).

The model number sticker with region coding is adhered to the underside, which is a little different.

Under the Hood

The unit is extremely cost-minimised and as a result, it only has two black screws to hold the outer lid on.

Under this lid, we see that the optical drive assembly takes up most of the space, and it’s a “bare bones” plastic unit with some of the drive electronics integrated into the smaller green PCB that contains the rest of the brains (i.e. SoC, RAM, Flash, etc). The brown board in front is the power supply board.

Removing the drive in this state requires removing the three ribbons that connect the drive to the green PCB, and undoing the two silver screws near the rear. As the drive’s front fascia plate is still attached and the tray would not open, the front of the unit has to be removed too.

To do this, one silver screw has to be removed from near the power supply board.

Then, three clips on the fascia have to be unclipped. Then the fascia will slide slightly forward.

Remove the two cables from the power supply board, and the whole unit should now break free of the main body.

It’s rather unwieldy to work with this assembly like this, so we must eject the tray and remove the front fascia plate.

This can be done by sliding the drive’s plastic mechanism responsible for the position of the spindle and laser sled towards the right with a thin screwdriver.

The tray will pop out slightly, then you can slide the tray out and clip off the fascia by pushing it upward relative to the tray.

Closer Look at the Drive

I decided to do my best to take it all apart and put it back together again so I can show what goes on in the drive. To do that, I removed two silver screws and the cross-arm that sits over the spindle area. Then, I slid the tray out completely by pressing the two side retention tabs to let the tray move all the way out.

As a result, you are now looking at the base of the drive – the two lasers each with their own lenses on the sled and the spindle in the middle, with the loading mechanism on the right of that. A white piece of plastic slides up and down (in the image) which controls the tilt of the sled and spindle – at one end it pushes it upward so that it “clamps” onto the disc with the cross-arm that was on the top. The cross-arm contains a metal piece inside some plastic, whereas the spindle contains a magnet, thus by magnetic attraction, the disc is secured to the spindle.

The slits in the white plastic allow for corresponding pegs in the black tilting platform to push it up into the “clamped” position, or down in the “retracted” position for eject/load. This piece is timed by two mechanisms – towards the end, the teeth on the right are engaged with the white cog to provide the final lock/unlock movement.

While the tray is loading or unloading, a channel inside the tray grabs onto the peg on the left of the piece, to stop it from engaging with the white cog until the tray is just about closed. When reassembling the drive, ensure the peg is aligned to the channel, else the tray cannot close.

You will need to use some finger pressure to do this.

The whole opening and closing procedure is powered by an electric motor. This drives a rubber belt, which drives the black cog, which then drives the white cog.

The logic which drives this whole mechanism requires on this white position sensor, which sits in the channel and gets deflected left or right to indicate fully-clamped or fully-released. Ensure the peg is within the limits when reassembling, or else the mechanism will not work.

Once everything in the loading mechanism is taken out, there aren’t that many parts to worry about. The main reason for problems in the mechanism are old dried out lubrication which results in stickiness or lack of lubrication and a stretched or worn belt along with slippery rollers. A stretched belt will slip earlier, thus not transferring enough torque to the mechanism to overcome the friction to “break apart” the spindle-and-metal-plate connection when it comes to ejecting. This is why such drives often have a symptom where they can always eject when a disc is in the drive, but become almost impossible to open when empty. The disc increases the separation between the spindle magnet and the plastic-and-metal-plate clamp, thus reducing the force required to lower the spindle-and-sled assembly. Almost all tray load mechanisms share the same principles, although PC drives are a little more tricky to disassemble as they must be extracted from their shell first by opening up the bottom PCB side first.

Some other drives avoid this failure mode by ensuring the motor is geared directly to the loading mechanism without a belt, however, these tend to be noisier. When these get stuck, it’s almost inevitably due to poor lubrication.

As I had no spare belt, and had nothing to measure it with to hand, I decided just to clean off all the lubrication and reapply some bike chain oil to all gears and running areas (although silicone grease is probably the best option). Do not get any lubricant on the rubber belt or you will regret it dearly – it will make it almost impossible to get working.

Reassembly and Test

When reassembling, a shortcut can be taken and the drive can be mounted into the frame without the fascia panel.

Once the whole unit is reassembled, eject the tray and then clip on the fascia panel.

Ultimately, my attempted fix without replacing the belt was only partially satisfactory. It’s increased the eject rate from virtually never to about 75% of the time. But it’s symptomatic of a loosening/slipping/stretched belt, and it looks like it will need to be replaced to restore full function. There are a few “generic” replacement belts on eBay, but it’s hard to know if it’s going to really be any better.

An Obvious Shortcut that I Missed

If you look closely at the bottom of the unit, there is a slot which matches up with a slot on the frame of the drive. This allows the white plastic bar to be moved from the outside, and is a form of emergency eject. As I am more used to the pinhole eject type, I totally missed that, and it would have made things a lot easier if I had noticed it. Unfortunately, not even the manual seems to say anything about it – but stick a thin screwdriver into the hole, and slide to the side and the tray will unlock and eject slightly.

If I were to disassemble the drive again, I would use this to prop out the tray, unclip the fascia panel from the tray, thus allowing me to remove the drive from inside the unit without needing to remove the whole front face of the player.

But even barring that, in case of desperation, you can just hit the eject button, wait until it gets “stuck” and give it an additional help through this slot. This can allow the tray to eject, although the “time-out” mechanism may try to retract the tray immediately, so you have to hit the eject button again in quick order to hold it open (or just force the tray to remain open).

Conclusion

It seems to be an unfortunate ailment for many motorized tray-loading drives that their trays get stuck. The reason boils down to poor lubrication and worn/stretched belts. It’s because of this that I had the chance to show the insides of the Philips BDP2180/79 3D Blu-ray player and take apart the loading mechanism of the drive to demonstrate its parts. I missed the emergency ejection slot mechanism when taking it apart – it would have been simpler if I had known, but this wasn’t even documented in the manual! While the “simple” lubrication didn’t quite fix the issue, it didn’t do any harm, and in time I might find myself back in there to replace the belt and fix it for good.

About lui_gough

I’m a bit of a nut for electronics, computing, photography, radio, satellite and other technical hobbies. Click for more about me!

This entry was posted in Electronics and tagged , , , , , , . Bookmark the permalink.

One Response to Teardown: Philips BDP2180/79 3D Blu-ray Player with Stuck Tray

  1. matson says:

    For those who willing to commit time and effort, but refuse to buy a replacement belt: there is a way to extend usefulness of a worn/aged belt. To compensate for diminished traction, decrease clamping force by increasing distance between magnet and ferromagnetic plate.

    http://www.youtube.com/watch?v=ePb9WpEi0qs

    Season’s greetings! I wish you a joyous Grav-Mass and new year.

Error: Comment is Missing!