Sep 072011

Recently I was asked for advice on how to troubleshoot a Color Classic that won’t power on.

There are a lot of great troubleshooting resources across the internet that address this topic with helpful advice. This post isn’t meant to replace them but simply to consolidate the recommendations I’ve found helpful in the past. Hopefully it will help you get your CC up and running!

1. First verify you are using a known good power outlet and cable. Remove any surge protectors or power strips as well as any external peripherals from the CC like attached hard drives, printers, or modems.

2. Be certain the power switch on the back of the computer is in the ON position (top part is pressed in). Make sure the keyboard is attached and firmly press the power button on the keyboard.

3. Reset PRAM (hold down command-option-P-R while pressing the power button, continue holding these keys down until the computer chimes at least 3 times, then release).

4. Unplug the power cable from the CC. Remove the logic board by taking out the two retaining screws on the back panel, then pressing on the tab at the top and pulling the panel out. Grasp the logic board firmly on each side and pull out directly.

a. Use canned air to blow dust accumulation from the logic board if necessary. Avoid the temptation to vacuum it since the static electricity can ruin the logic board.
b. Clean the contacts at the front edge with a cotton swab moistened with isopropyl alcohol.
c. Clean the socket inside the CC the logic board slides into with a cotton swab moistened with isopropyl  alcohol.
d. Remove the memory SIMMs (and if present, the VRAM) and clean the contacts with a cotton swab moistened with isopropyl  alcohol. Carefully reinsert them and be certain they snap securely into their upright position.
e. Press the CUDA switch briefly on the logic board (the tiny button near the ADB ports) and release.
f. Reseat the logic board by sliding it in and making sure it snaps securely into place. Remove and reinsert it a few times to help insure a clean connection.

Plug in the CC and see if it starts up.

5. If the CC still won’t start up unplug the power cord, remove the logic board and take out the 3V.6 battery on the logic board. Reinsert the logic board, reattach the power cable, and try again.
6. Sometimes the CC needs at least 24 hours with power attached and the switch on the back in the ON position before it will revive.

Still no joy? Remove the logic board and inspect it for traces of leakage around the capacitors (dark areas). If you see evidence of leakage if may be shorting the trace connections on the logic board. Believe it or not, a trip through the dishwasher is recommended for this. I won’t be the one to guide you down that road, though, I’ll leave it to those who have done it. See these great forums for assistance:

Good luck and feel free to post comments and results below with your experiences troubleshooting the Color Classic.


  4 Responses to “Troubleshooting a Color Classic that won’t power on”

  1. Hi,

    I just wanted to drop by and say, great site! There is a great amount of useful tips etc for old macs.

    I recently purchased a couple of Color Classic’s. One needs replacement capacitors but the other works great.

    My next task is to get AppleTalk working with an old PowerMac G3.

  2. thanks for the kind words, Michael. Great to hear from a fellow vintage Mac collector.