Hi,
I am new here as I picked up a CD A405 and I saw the topic being new and not decades old.
1.)
You can see a good page when you just search for "cd laser list" in google, it may bring up a list like this one (or similar). There are most (not all) players listed:
vasiltech.narod.ru
According to that information, the CD A405 uses:
DAC: PCM56P-J
Laser: MLP-4
If you want to search for laser, often the term "pickup" is used, so try that. NEVER buy any laser that says "is for CD A405" - they rip you off. Search the part number, and search for that.
2.)
I picked up a CD A405 in black and it did not 100% fully work maybe - I checked it over and that is what I did to make mine work:
First, the rubber band/belt was worn and it needs a good one as it pushed down the CD inside the drawer. That's why it takes so long to eject as the first spins are just moving the CD up, and if that is completed, the CD drawer comes out. So make sure that it is a new belt or working as it may also impact performence.
Secondly, check the board, there is a place on the upper left side with some Aluminium cooling fins where I had some glue applied. This glue can turn to corrode metal and also conduct power, so basically it can screw up your board or parts. It was not in a serious amount or in critical components, but it did touch some metal clamps/zero ohm resistors that it may impact something. And if not now, it may corrode something in the future, so remove all the brown colored brittle glue and make sure the parts are clean and seperated. Do NOT remove the board, I looked down and there is nothing I found. There is no glue on the bottom and no bad solder joints, so as long as it works, dont touch it. Why do I say that? Because they have some re work done with many parts and wires and whatever, so it's not worth to get into problems if you dont have to, e.g. when a wire falls off or something.
Thrid, I unplugged all the plugs and one GND ground wire (left top screw of the board) and removed the mechanism. At best, open the CD drawer and unplug the power. Close it manually, BUT NOT FULLY CLOSE IT. Leave a gap of about 1 inch or 2-3 cm open. Then unscrew the screws, there may be 3 screws on the bottom and 2 on the top (you can only see/remove those when the drawer is open). Unplug the plugs, I guess it is 3 plugs and the ground wire. Then slide the mechanism out through the back. The lid of the drawer fits through the opening. Turn the drive around and replace the belt. Also remove all the old greece (its really old and sticky and disgusting maybe) that they used and maybe lubricate the rails. You should not really use oil but if you dont have anything, take a Q tip and go over the rails, it will make it a bit better or mix it with the old stuff etc.
You can remove 2 screws on the top on a metal piece (its the magnet that spins the disk) to get a bit more access to the laser. You can slights clean the lens with IPA 99% alcohol but in my case it was pretty clean anyway. First maybe check the rest, or see if it is dirty, because cleaning the lens also is a bit of a risk, so do it step by step maybe.
What else? Well mine kinda read the disk well but did not like to go to the next track, but I think it was because of the rails and oil and stuff. After some use (it may have been sitting for years before I bought it) I let run through some CDs and after some "exercise" it also jumped well between the tracks. It makes a littles noise but I guess that is okay. It's really quick in reading in the disk and everything.
There are also 5 potentiometers on the board, at least. They are also marked with T GAIN, T Offset (Tracking) etc. You can maybe try to play a bit with those, depending on what your machine does. MAKE IMAGE BEFORE CHANGING anything. Change one by one in each direction by maybe maximum 1mm, and see if it goes better or worse. I did not have much response from those pots, but depending on your issue it may get better. There also maybe another pot directly on the laser, I did not go that deep.
You have to tell us what to does, I am not a wizard to see your unit. You know? Open it up, the laser is covered, but DO NOT TOUCH THE POWER SUPPLY, IT HAS MAIN VOLTAGE. PSU is behind the CD. Other than that, nothing much can happen. So see what it does? Does it take in the disk well? Or is the belt worn? Maybe it never goes down inside correctly? If so, does it spin the disc? Does it tell you what numbers and length the CD has on the front display? Or does it not maybe play correctly? If the latter, it may be down to the rails and the sticky disgusting oil they used. It will not move correctly and get into hiccups.
It do not have any issues with the laser, it also reads CD-R media.
3.)
Depending on where you are (I am from Austria) I have mine up for sale here (220V Unit):
I can ship it to you as long as you pay the shipping but if you are from USA or something it may not be worth the shipping cost.
Good luck and tell us what happens.