We did a lot of work at Thwocker's.
First of all of course we re-installed the WG6100 in the Tempest cabaret. Of course we did some final tweaking to the monitor and PCB settings to get an as good as possible picture. It looked pretty damn good
Next up was reinstalling an AR-II board from Thwocker's upright SW that I had taken to check in my SW cockpit. It worked just fine so Thwocker's SW had another issue.
The thing is when powered up, the marquee and monitor powered up, but the board-set stayed dead. I had checked and there was no +5V. So , since I was in a bit of a hurry last time, I figured it was most likely the AR-II was dead, which it wasn't in the end.
So I tracked back why there was no +5V. I suspected about everything, like the diode bridge on the power brick etc.
We switched both AR-II and Power Brick with the Space Duel but they both just worked in the Space Duel. I was puzzled !!!
Re-installed everything in the SW and .....it worked !!! HUH
??
So I was falling back to a proven concept in fault-finding: move wires, tap (carefully) on boards and stuff and yes, soon enough I found when I touched something on the power brick the power went down on the PCB set again. But I had checked the fuses and stuff.
And then, while fiddling around I felt that the wire coming from F2 was hot. Really damn hot, I almost burnt my fingers !!!
So I removed the AMP clamp and it was very clear right away: the fuse holder had gone bad. Really bad.
Now, I have never seen this type of fuse holder on an Atari brick. I suspect that it was replaced before.
It has the looks of a (cheap) Chinese fuse block.....
Have a good look at the picture. You can see that the fuse holder has turned dark at the spots where the metal is connected to the plastic. Also, especially on the right, you can see black stuff.....it is slowly burning !
Luckily Marco had a spare fuse holder board (exactly like the original) that we scavenged from another power supply (don't know from what machine that was). I transplanted everything and fired up and bingo, problem solved !
In my years of electronics experience contact problems have been the cause of about 80% of failures, maybe more. This was another one, but it took quite a bit of time to find it.
