We have two 8000's: a 1997 and a 2002 unit. They have different power paks.
BIG race (for us) last Sat. University Carnival. I switched the two clocks on at 6:50 to warm up. Both turned on, but only one had the red "external power" LED on. Switched the power paks. The LED moved to the other clock. Opened the bad (1997 model, about 6" x 4" x 4"; the newer unit looks like one for a laptop) power pak and quickly determined the input (115 VAC line) fuse was blown. We did the race with one power pak, switching it back and forth between runs to keep the batteries in both 8000's charged.
On Sunday, I determined that there was nothing else wrong with the power pak; only the fuse was blown. The fuse is a 750 ma European 5 x 20 mm glass cartridge, almost the only fuse size used in Europe but not readily available here in the states. It was installed in an in-line fuse holder which was VERY poorly hand soldered into: 1: The PCB; 2: a wire from the transformer.
This fuse apparently blew for no good reason. I can't see how the output DIN plug could have gotten shorted. Replacing the fuse put the unit back into operation. I guess the fuse blew on the inrush current when it was plugged in.
MORAL: Better have a spare fuse or two available. I suggest opening the unit and finding out what the fuse is and getting some spares. This is not a good thing to have happen on a busy race morning. I would also recommend having either a spare power pak or a DIN plug wired to connect to a car battery (I recommend an in-line fuse).
I replaced the fuse holder with a USA 1/4" x 1+1/4" standard type, and taped a box of five new fuses to the unit.

Jim Green
Wildcat Ski

The fuses have been available at Radio Shack. I have noticed in recent months that Radio Shack is making a concerted effort to eliminate stock in parts and "hobby" parts. We will look into stocking the genuine fuses from Europe.

I apologize for the double post. Strictly my own error.
Yes, the fuses are obtainable through a specialty store, like Radio Shack or Active Electronics. My point, simply, is this:
1. The fuse blew for no apparent reason. There was no failure of the hardware in the pak and no short on the output.
2. When someone has a crucial piece of equipment which is prone to inadvertant opening of its fuse, one should have spare fuses on hand and know how to change it quickly.

Jim Green
Wildcat Ski Club