Summit generator advanced troubleshooting page
Innovets with W400 generator or Nova 325/360
with intermittent exposure problems
The Innovet or any generator with a footswitch. The problems with a footswitch, especially using the Limemaster 636-S, is what can happen within the footswitch. Dog or cat hair is going to get into them. I've opened some before and it's nothing but a giant hairball and I've seen this alone cause problems with the switches.
The correct adjustment of the switch travel between the two switch stages. First stage should be with minimal travel, with good spacing before hitting second stage (expose). This is way I've found most Vets want them adjusted. Second stage should be the almost end of the travel.
Never splice the S/O cord from the footswitch to the generator. I found one where this had been done, moisture got into the splice over time, setting up a condition of high resistance (intermittently of course), driving the kV/mAs interlock board and myself, almost into insanity. This was a very intermittent problem. The kV display would display "666", between a few seconds to several minutes after power-on.
Completes exposure, but intermittent output, no output or radiation
1. Check filament at the tube, small and large focal, by visual observaton. It's a good idea to check the hi-tension cable end pins. If they are the brass, split pin type, slightly spread them apart. They are brittle, so be carefull.
Hi-tension cables do go bad. It's possible, with flexing the cable, that at times, you have connection through all the conductors of the cable and at other times you don't. For instance, if the common conductor of the cathode cable is intermittent, you could lose small or large filament voltage at the tube, intermittently.
2. If filament is still intermittent at the tube, check XC, XL and XS connections at the top of the tranformer and at the generator. Select large focal and measure the a.c. voltage between XC and XL and the cable end pins at the tube, Do notattempt an exposure. Repeat the same for XC and XS. You're looking here for about 10-12 volts from standby to prep and about 6-8 volts, respectively, for small focal. If this voltage is not stable, check the adjustment bands of the large ohmite resistors. Some will corrode over the years causing a loss of the voltage.
3. About the most common cause after the above two items, is the mA selector switch. They do fail from time to time. Failure of the mA stabilizer transformer? Not that often.
If you're not losing filament, but still having intermittent output problems, a faulty major or minor kVp tap switch can cause the problem and many times will be intermittent resulting in losing voltage to P1/P2 and a loss of kV. The major kV selector gets used the most and is the more likely to fail.
These are the basic troubleshooting items for these problems. Other p.c. boards in these generators do fail from time to time. The timer board also had a pretty high failure rate. The kV/mAs interlock board, it's had some issues over the years. The A455 motor start board, I've seen it fail the most of any board in the generator.
For more troubleshooting, click on "Other W400 troubleshooting info", below
Loss of kV/mAs display readout on Innovet tubestands
Check the ribbon cable connections from the tubestand to the generator. Almost always the cause. There were some issues with these cables.
Preps w/rotor but no exposure, no beep