CD Drive Salvage Part 1 - Tear Down and Inventory

This whole expedition was inspired by Tinkernut's tutorial on turning CD Drives into a CNC Machine. I wanted to try my hand at it and maybe take a different approach. As I am very new in the world of electronics, this is a huge undertaking. I honestly have no idea what I'm doing but it's exciting to try.

I'm not just going to make a CNC Machine, however, but I'm also going to make stuff out of the rest of the motors (and maybe lasers). I have a few ideas about what to do here, but I don't exactly know if I can do those things yet. But we'll get there in another part. For this post we're only going to be focusing on disassembly and salvage from these drives.


First I had to acquire CD Drives. I got 4 just in case, and I also got an ATX Power Supply from my local electronics surplus store. They had a few boxes full of CD Drives back there, so I chose the four with the highest data transfer rate (thus higher drive motor speed.)

They're old but they probably still work.

I decided to dissect the slowest drive first, the 32x drive. This one was a Lite-On IT CD-RW Drive Model LTR-32123S. Taking the casing off was trivial. Do be careful not to be too rough with the logic board as it is connected to other parts of the drive.

The inside of the drive.

Broken down into three useful thirds.

I broke the drive down into three main parts (excluding the case):

1. The Logic Board. This may have some useful stuff on it, but I'm not holding my breath. The useful components have been soldered on pretty well.
2. The Main Drive Assembly: This includes the interesting stuff: the stepper motor that provides linear motion, the brushless motor that spins the disk, and the laser. This CD Drive is a read/write drive, I don't know if that makes the laser special or not. I can only imagine it does but I'll have to read more into that later.
3. The Drawer Assembly: This also provides linear motion through a complex series of gear reductions.

I then proceeded to take apart all of the other drives. Two of the ones I got were devoid of stepper motors. One of them was really strange in that it had a weird worm gear setup. I'm not sure what I'm going to do with this yet, but it sure is odd.

Every thing has been torn down.

Next, for some reason, I wanted to take the chips off of the board. Most of them will probably be useless. Some of them are probably made specifically for this purpose. Some are probably one-time programmable EPROMs. I know the first chip I pulled certainly was.

This Holtec HT27C512-70 is a one-time programmable EPROM

There were more chips on here that could be of use. There are a few microcontrollers on here, as well as a few ICs used in headphone circuitry.I just decided to pull all of the chips on the board. I wanted to keep the pins relatively intact, so I decided to carefully remove the chip with heat and pliers. With a heat gun, I heated the chip and its surrounding pins and, when the pins were liquid enough, I pulled the chip up with a pair of needlenose pliers. The pins keep their shape really well. I think it's important to warn the the board will get very very hot, and you risk damaging components and possibly burning something you shouldn't (making it smoke and perhaps produce toxic gas.) Do this on a non-burnable (I made this mistake by burning a table) surface. I used the ground (after I burned a table) and placed the chips on a piece of paper. They didn't stick to it as the metal solidified. 

Heat it up...

...and pry it off. Don't over do it and don't grab it by the pins like this posed picture.

Below I have listed the chips I have salvaged from these CD Drive Logic Boards. I've linked relevant datasheets as well as gave a short description of what they are. This is more for me, but whatever. Here it is anyway.

Chip Number	Quantity	Notes
MT1508E/MT1189E	2	Not a lot of documentation on this.
W78C32BP-40	2	8-bit microcontroller. One of them has a slightly different model number.
BD7902CFS	1	6CH Power Driver for CD-ROM, DVD-ROM
MT1102F/MT1516E	2	Not a lot of documentation on this.
M10B11664A	1	DRAM Chip
M12L64164A	1	Another DRAM Chip
39VF040	1	Flash Storage
LB11995 / BA6849FM	3	Three-Phase Brushless Motor Driver for CD-ROM Spindle Drive
W27E257P-10	1	32K X 8 Electrically Erasable EPROM
24WC08J	1	Serial E2PROM
A416316S-40	1	64K x 16 CMOS Dynamic RAM with fast Page Mode
CXD3030R	1	System on a Chip specifically for CD Drives
TC9450F	1	Probably a volume control, not sure on this one.
PM39F010-70JCE	1	CMOS Flash Memory
74HCT373D	3	Octal D-type transparent latch; 3-state
LA6543	1	4-Channel Bridge (BTL) Driver for CD-ROM
74HC4066	4	Quad single-pole single-throw analog switch
CXA2581N	1	RF Signal Processor for CD Players
TA2111F	1	3V AM/FM 1 Chip Tuner IC
A4558F	1	Low Noise Dual OP AMP
MS6308	1	Class AB stereo headphone driver

There you go. Four drives, torn down. Next step, making the lasers shine!