Tuesday, January 31, 2012

Philips CDI 450 Repair: Laser Replacement

So in a previous post I mentioned how I bought a CDI 450 from a seller on ebay that had a laser that didn't work. I also said that I was planning to fix it. Well I managed to get it back up and running and have decided to put a tutorial up here because to the best of my knowledge there isn't any tutorial on replacing a CDI 450 laser on line. At the end of this I'll put a link to two youtube videos that I found very helpful. One is a teardown of a CDI 450. The other is a video of the laser replacement on a Jaguar CD, it uses the same type of laser and is very similar to the laser replacement on a CDI 450.

Anyway the first thing you will need is a new CD unit. The CDI 450 uses a CDM 12.1 model. They don't make these anymore but the VAM 1201/1202 laser unit is compatible and there's plenty to choose from on ebay. This tutorial will only apply to the 450 model but can be used as a reference for other models that use the CDM 21.0, 12.1 and 12.2 lasers. I bought mine from this auction here:

Shipping was free from Hong Kong. It took a while to arrive but worked fine when it did.

Before I continue I want to have a bit of a moan about the CDI 450 version of the CDI range:
The 450 only has composite output, which if you know me, infuriates me. Composite is god awful and I'd much prefer RGB. The ethernet port you see is actually the power port, the system is powered from an ethernet cable attached to the power supply which is weird to say the least.

Anyway first off you have to remove the cover over the Digital Video Cartridge slot. You'll need to remove the DVC if you have one, I don't unfortunately.

The next thing to do is to remove the four screws from under the CD lid and the DVC slot, I've circled them in Red. You'll need a small allen key since the screw heads are hex shape. One thing to note is the light grey circular piece hanging from the underside of the CD lid. This is a magnetic weight that keeps the CD firmly on the spindle. This will be important later on. When the screws are removed you can take off the top shell, you might need to apply a bit of outward pressure on the corners. You'll be presented with the view below.

Now remove the useless metal shielding. Be very careful not to break the thin wires that connect the CD drive to the motherboard. As you can see they are held to the shielding by a white piece of plastic, be careful! Once removed you should see this:
The next step is to free the CD drive wires from behind the CD drive. Be careful, you don't want to lift the CD drive too quickly, you might break the wires and the ribbon cable connected to the motherboard. As you can see in the picture below the wire harness and ribbon cable are connected to the motherboard and need to be removed.
Once these are disconnected you can lift the entire CD drive assembly out of the system. There's an annoying piece of plastic at the back that keeps the CD drive assembly in place which came off when I tried this. Don't be alarmed since it's useless and more a hindrance than anything. I've marked where it is in the below picture with a red circle. It is now forever rattling at the bottom of my console.

Next remove the CD drive from the metal plate. It will be held above the metal plate by four rubber holders that act as the shock absorbers for the assembled unit. You might need to force it with a screwdriver or knife. You should have the CD drive with attached wire harness which now needs to be removed.
There's 6 solder points that the wire harness is attached to. My advice is to draw a diagram of which colour wires attach to where on the CD unit. My own crappy diagram is below:
Why so glum at the bottom?

Two solder points are on the CD spindle motor, marked in red below. Another two solder points are as a switch marked in blue below. Sorry for the poor quality of the photo, you can see much better in the video of the Jaguar CD repair at the end of this tutorial.

The last two solder points are at the lateral motor at the back of the unit.
Remove the wires from these solder joints by holding a hot soldering iron to the solder until it softens and pulling the wire away. Below is the freed wire harness and the new VAM 1201 laser unit. Remember to keep the laser unit on an antistatic bag or if you don't have one then a sheet of A4 paper like I used will suffice. The new laser is a little different, with a different coloured spindle and also a smaller lateral motor as shown in the two pictures below. The ribbon cable is also protected by a metal protector that needs to be removed later.
Black spindle instead of grey
Smaller lateral motor
The next step is of course to reconnect the wire harness in the same manner as with the previous CD Unit. A small amount of solder needed to be applied to each solder joint other than the two lateral motor solder joints which handily had solder on them already. The new CD drive with attached wire harness is shown below.
Next is to attach the CD drive to the metal CD drive holder. Just slide the rubber shock absorbers into the appropriate slots on the CD drive. It shouldn't offer much resistance. Next attach the wire harness and ribbon cable to the motherboard as below. I found the ribbon cable extremely tough to get into the ribbon cable connector on the motherboard and it required a lot of force to get it into it. Be careful not to damage the ribbon cable when doing this. The first time I assembled the CDI the CD rom drive did not function at all and I believe it was because the ribbon cable was not fully inserted. Try and get it in as far as you can and don't be afraid to force it. I managed to bend the end quite a bit but it still worked. Not recommended but you might have to do the same. The ribbon cable connector will not fully cover the exposed metal ends of the cable but it should still be pushed a fair bit into it. This is the most awkward part of the repair.
I found it very awkward to run the wires around the back of the CD drive assembly and get the assembly to sit properly so instead I ran the wires under the CD assembly instead of behind it like they were arranged initially. I used some sellotape to hold them together as below. It's now time to re-assemble the CDI once the CD drive assembly is in place. If you are putting back on the metal shielding be careful not to cut the wires, especially if you run the wires under the CD drive assembly like I have.

You should fully assemble the CDI including the four hex screws that hold the top shell casing in place. I found that without these screwed tightly the system would not recognise when the CD lid was closed. Next stage is the testing stage. This is where I ran into some more trouble so please follow the next few steps.

You should first test the CDI with the CD lid up. The magnetic weight in the CD lid is removable. Take this out and place it on top of the CD you want to test with. My advice is to start with a music CD. The magnetic weight will hold the CD in place during testing. Without it the CD will slip and be unreadable and make some horrible grinding sounds. Use a small thin object, I used a DS stylus, to hold down the closed lid switch to test if the laser will seek and recognise the CD. Here's an extremely bad picture of me doing this, notice the magnetic weigth is removed and sitting on top of the CD.
I apologise again for the crap picture quality
Once you are sure that the CD drive is working the next step is to test the unit with the lid closed. This is where I ran into trouble. Remember to put the magnetic weight back in the CD lid roof before starting. If you are lucky the CDI will run perfectly. If you are unlucky like me your CD drive might be a few millimetres off and you will hear the horrible screeching sounds of the magnetic weight rubbing against its enclosure. If this happens you can try adjusting the position of the CD drive until you get it right but this was too much of a pain for me. I instead completely cut out the magnetic weight's enclosure. This was a total pain to do and involved slowly cutting away at it with a saw and then shaving pieces off bit by bit with a sharp knife. You'll have to make sure you get rid of almost all of the plastic in there to avoid the magnetic weight rubbing on it. I've a picture of what I did below, be warned, it isn't pretty.
Yes I know it's a real hack job. I now need to place the magnetic weight on top of each disc manually but it's not that much of a pain and well look at the pictures below, it actually works!

I hope this tutorial is of help to people since I couldn't find any tutorials myself online. I suggest watching these two youtube videos before you start. The first is a tear down of the CDI 450, this will show you how to open the system up:

And the next is a guide to replacing a laser on a jaguar CD unit. I found this the most helpful since it's the same laser as in the CDI 450.

Happy soldering!


  1. I'm glad you finally got it working p(*^-^*)q

    1. So am I! Zelda CDI games here I come!

  2. Impressive! Good job on making it work. Are you going to review the games you have for it?

    1. Yep going to play a few games for it and will definitely write reviews. A lot of the games need a DVC though so will have to get one. At least there's no copy protection on games so can try a lot of the library out. I got the system from France so a lot of the original games I got are in French which doesn't help!

  3. I have a problem with the laser motor, it moves the laser head until the end and it doesnt stop from moving, making a click noise because of the gears moving on and on, even if the end-of-line trigger seems to be pressed. Any ideas ? is it the motherboard or the laser assembly (I've even disconnected the ribbon, same thing). The menu appears on screen, I can operate all ok. Thanks for any hint.

    1. It's more than likely the CD unit. Replacing it should fix it.

  4. Thank you.
    My 450 is now working.
    Well mostly. Sometimes the disc starts to spin when I close the lid but then stops.
    I have to open and close the lid several times whilst it is still spinning and then it works fine but at least it reads disc's again

    1. You might need to shave off the plastic on the lid. When I did this the Cd was getting caught in the plastic on the underside of the lid so I cut it off. It wasn't pretty but it worked.

    2. It does this even with the lid open and if I push the close lid switch like you did in your repair.
      Not too much of an issue if I can get it to eventually start and I have my trusted 470 that works flawlessly.

  5. Done my 450 this week along with a new timekeeper. Was surprised how much noisier the new mech is compared to the old (genuine Philips too). I find the new laser mech is far more sensitive to disc imperfections too.