Step 1
Place the CoCo upside down and locate all the screw holes.
NOTE: the one in the middle, circled in red is not a screw, and you will end up damaging the finnish (like I did). the blue circles are just to hold the keyboard in place. But, go ahead and remove all of them.

Figure 1a

Step 2
Carefully flip the unit over and remove to top shell. You should now be able to see some thing similar to figure 1b. There may be more shielding than shown. REMEMBER on the VideoTex Page, how I mentioned that this was in fact the same shell used for the VideoTex, if you flip the top shell upside down, you will see under the "Button" label- the hole used for the "DATA" LED on the VideoTex.

Step 3
remove the screw below the Power supply (figure 1c), and unplug all the leads (don't worry, they are labeled, except the main power cord, so you may want to keep track of those 3 leads. (when I get a complete service manual, I will update these steps)

Step 4
You should now have the Power Supply disconnected. Carefully lift the PS straight up, off the "Cradle" and put it to one side. Now is a perfect time to inspect the PS to see if there are any burn (overheating) marks or leads that need to be re soldered. I recommend if you have the skill, to replace the five wires on the PS, because they can become stiff and brittle. Why risk a fire hazard for 20 Cents worth of wire and five blade leads.

figure 1b

Hole for the VideoTex DATA LED

Figure 1c.

Power supply flipped over and still attached

Keyboard Removal
Step 5
Now that the power supply is removed, and all the screws underneath, CAREFULLY flip the keyboard up and towards the back, there is a small cable connector underneath and at the back and over time this can become stiff and fragile. (figure 2a).

Now with the keyboard safely disconnected you can take off the connector an place both aside.

Figure 2a

Close up of connector

Part 3 Motherboard

Good news! we are almost there

Step 6
Now the the keyboard off, you should see something similar to figure 3a.
Step 7
Remove the 10 Fastening screws that hold the motherboard in place.
You can now Carefully grasp both sides of the Motherboard, and slide it straight up, over the screw supports and place it on the workbench.

Step 8
You can carefully take off the metal cover over the micro chips and CPU. It should look like figure 3b. Carefully take some compressed air and blow all the dust off the motherboard. Carefully inspect the motherboard for obvious signs of damage, burn spots (indicates blown components),and corrosion. You may have to re-solder some traces.

That's it. to put it all back together, reverse the steps.

figure 3a -Keyboard off

Figure 3b

But wait, now that its apart, lets take a closer look.
Most web sites state that the CPU is soldered right to the board. Not true, on this model, EVERY Chip is socketed and removes (somewhat) easily.

Interesting, EVERY Chip is Motorola, but the other components are all assorted. Every chip is labeled in big letters MOTOROLA-except the CPU (Circled in red), you almost need a microscope to read the label, The 2 other chips circle in blue are the only 2 chips that have TANDY 8040364 on them .These are the Extended Rom Chips
There are 30 microchips in all. (Figure 4a)

The following is the step by step guide that the manual suggest:

DIASSEMBLY

1. Make sure all cables (also power cord) are disconnected. Place the Color Computer face down on a pad or non-scratching surface and remove the seven screws from the case bottom. (Because the screws are positioned so deeply, you may not be able to remove them until the computer is turned face up).
2. Carefully place the Computer face up and lift off the Case Top and set it aside.
3. Carefully lift the keyboard off the plastic bosses and remove the keyboard cable.
4. Remove the Top Cover Shield and set it aside. You may have to remove the top cover of the modulator (U5) to get the shield off.
5. Remove the three screw supporting the transformer assembly (two on transformer, one on board) and disconnect all jumper cables.
6. Remove the ten screws fastening the CPU PC Board and lift the Board off its plastic bosses.
7. Remove the Ground Plane and Insulator from the back of the PC board by using a screwdriver or other small, thin tool.

.
The teardown Procedure is exactly the same as above, and at first glance , the Motherboard looks almost the same as above. This Motherboard is the "E" variant (where as above was the "D" board. The markings are 8709137-E , and a second number 1155751 which I assume to be the S/N of the board or an inspection label.

CLICK HERE OR PICTURE FOR ENLARGED VIEW

Update Feb. 09 (sort of)

I recently got a Very bad shape 64K white CoCo 1 in. I decided to take it apart to soak the case, as it was caked with grime. The basic tear down of the model 26-3003b is the same, but the motherboard is completely different. I tried to take some photos, but my new digital camera is worse than the old one at close range, so I did the next best thing. I fired up the old scanner and forced 2 more scans out of the old thing.

This board is labeled 8709285.One of the first notable items is the Cartridge slot. The whole assembly including the door, is bolted right to the board.

For a really big photo, Click here.

The CPU is a 6809EP as the 26-3001 was a 6809E.
The "P" just indicates a "plastic" package (thanks to Mike for the update) , He also claims that this is indeed an "F" board, as it was common not to have the letter "F" stamped into the board, but all the other boards did have the letter stamped in.

There is a trace wire across the board.It runs from beside the #6 pin on the 6847P VDG on the motherboard to the #3 pin on the 6822P (which I am assuming is another PIA (peripheral interface adapters). The 3001 has 2 6821 PIA's , this one has one of each . I am not sure of the exact reason.

It appears that the trace in the board was damaged. looking closer, behind the solder point on the broad there is a hole drilled in the trace. near the PIA there is another hole drilled in the board. I suspect that this was done after factory, because even though the warranty stickers were still intact, there was a second sticker slapped over the first and felt marker writing inside the shell. They are not signatures of the designers (no such luck, getting a 'one of" machine). So I suspect it was tech notes.

I Know its hard to see, the wire is blue and I drew the red in so it stands out a bit better

The Ram Consists of 8- 8K chips. Oddly enough, there is are 2 jumpers on the board marking 16K to 64 K.
Possible this could mean the same Motherboards were used in the 3003 or another 16K board .

Row of Ram

Jumpers

There is a relay behind the Cassette port.

Instead of cutting out a hole for the power supply, they just notched this one.

I have been told that this looks like an "F" board. I haven't found any "letters" in the board yet, so I can't confirm or deny that statement. I do not have an actual "F" board (that I know of, I haven't cracked open my other CoCo 1's- Maybe soon) to compare it with. Another project for another day.

The Keyboard was next to be cleaned. The "new" "melted" keyboard is used on these and the CoCo 2's. I would imagine Tandy realized the Chicklet keyboard was just plain bad, and many after market upgrades were sold , they went to a new design. They Changed the connector from a ribbon Cable type with steel leads (picture above) to a plastic sheet. You must be very careful upon removal, for these can be fragile.

Next, I carefully removed the keys by taking a blade screwdriver and carefully popped the keys up and off, slowly .

Once the keys were off, I socked them overnight in "OXY Clean and water.

Next, I removed the 18 micro-screws on the back and carefully removed the plastic circuit board. Now just flip the board over to remove the "spacers and rubber ends". They should just fall out freely.

That's it, it just depends on the cleaning solution. I have not found a great one yet, but Fantastic seems to work the best, This is the first time with OXY-Clean.

Slowly pop the keys up and off (click for a big photo)