iSight, G5, Firewire Problem Solved — Well, Sort of

I track down an iSight problem to Firewire.

When I got into a regular back up routine, backing up my hard disk to an external hard drive, I immediately began having problems with my WebCam. My WebCam uses a standalone (i.e., not built-in) iSight camera and EvoCam software. The problem usually manifest itself by creating a “split screen” image like the one you see here.

The only way I could correct this problem was to disconnect the camera, quit EvoCam, relaunch EvoCam, and reconnect the camera. That usually cleared up the problem for the day, but sometimes it would come back.

My Setup

Part of the problem is likely my setup. Here’s the important stuff:

• I have a Dual 1.8 GHz G5, which I believe is about 3 years old now.
• The computer has 2 Firewire 800 ports: one in the front and one in back.
• The iSight is a Firewire 400 device.
• The backup drive (at first) was a FireLight Firewire 400 portable disk with no power supply. Later, I bought a Seagate Firewire drive with an AC adapter for power.
• I was connecting the iSight to the second Firewire port on the hard disk (I tried both), the Firewire port on the front of the computer, and a Firewire hub (which was powered).

For the longest time, I thought the problem was related to power. That’s why I tried the powered hub. When the problem didn’t go away, I was stumped.

And then I had a logic board failure.

I can tell you what a logic board for a dual processor G5 costs, because I paid for one. It’s about $650 plus installation. The computer was only a year and a half old, but I didn’t have the AppleCare protection plan (which I now buy with every Apple computer I purchase). It was too new to replace with a new computer — I like to hang onto my desktop machines for at least 3 years — so I replaced the board.

I figured that the bad board was causing the Firewire problem. But when I got the computer back, I got caught up in other things that kept me too busy to mess around with a Webcam. I set up another Webcam on my server (which was in my office at the time) and let it go at that.

The Problem Returns

Time passed. I moved my office back into my house (and now wonder why I ever moved it out). The server computer went to KBSZ to handle automated podcast recording and database hosting tasks there. They have a studio Webcam but that poor eMac’s RAM is so stretched with the tasks it already does, that I couldn’t see setting up a second outdoor view Webcam on it. So the View Out My Window (also known as SaguaroCam, because of the tall cactus in it) was gone.

This week, I tried again. I had it working for about 24 hours, then the same problem returned.

Now I was concerned. Perhaps the logic board problem hadn’t caused the iSight problem. Perhaps it was the other way around. Perhaps continued fiddling around with this would cause another logic board failure. I certainly didn’t want that.

But it was bugging me that I couldn’t resolve the problem. So I decided to troubleshoot it.

Troubleshooting the Problem

Troubleshooting is a logical process. You need to isolate various parts of the problem, analyze the results, and repeat the process until you figure out what the problem is.

(I used to teach a troubleshooting course for Mac users. Over the course of two days, every time my class left the room, I’d screw up their computers. When they came back, we’d troubleshoot to find the problem. It was a lot of fun and had me flying all over the country, staying in crappy hotels and meeting great people. Ah, the days.)

My first task was to see if there was any help online for the problem. But I came up blank both on Apple’s support Web site and with a Google search. Either I wasn’t putting in the right search phrase (highly likely) or I was the only person in the world with the problem (possible but not very likely).

I suspected the problem had to do with Firewire. So I performed the following tasks, checking to see if the problem returned after each step:

1. Replace the cables. I’m fortunate enough to have spare Firewire cables. (In fact, I think I have enough cables to start my own cable supply outfit. How does that happen?) The problem continued.
2. Replace the iSight camera. Believe it or not, I have a spare one of those, too. Still had the problem.
3. Try plugging the hard disk into the front Firewire port and the iSight into the back one. This made a mess of the cables, and I still had the problem.
4. Plug the hard disk in with USB and plug the iSight directly into the computer. Ah! Everything worked!

I was fortunate that the Seagate external hard disk had a USB 2.0 port. After fiddling around to find the right USB cable (I have ton of those, too), I got it plugged into my powered USB hub. The result: everything works as it should.

Conclusions

The conclusion I’ve drawn from all this is that my computer, for whatever reason, simply does not like running an iSight — either one of mine! — with any other Firewire device connected, no matter how it’s connected. My solution — which I believe is a compromise — is to use USB, which is slower than Firewire, for the hard disk. Since the disk is used for backup and the backup occurs just once a day at about 5:15 AM, that isn’t a huge hardship.

But what may be a hardship is importing video from my digital video camera. I plan to do more work with video in the upcoming months, and I wonder whether I’ll have to disconnect my iSight camera each time I want to bring some video into my computer.

I’m scheduled to get a new production computer in October, when Leopard comes out. I just hope that computer’s Firewire bus doesn’t hate my standalone iSight camera as much as this one apparently does.