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Power supplies and things that can kill them
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Posted 6/24/2005 1:16 PM
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This applies most particularly to Mike Ross, but anyone else who tries to put a KL-10 into running order needs to be aware of this.

The muffin-style fans used for cooling on the main power supply have at best a 10 year working life, less if they have sleeve bearings rather than ball bearings. We had an outage on the 2065 this week when a dead fan caused a heat-related failure in one of the large power bricks. The brick can probably be repaired--power transistors are still common in the world--but even so.

We also lost an H744 5V regulator in the 11's power train during a lightning storm a couple of weeks ago. One of the large input power traces under the small filter caps (roughly 5mm across) had a 5mm circle melted out of it, with scorching of the cap.

So condition your power as much as you can, and watch those fans!
Rich Alderson (RichA@Vulcan.com)
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Posted 6/28/2005 10:09 AM
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Did the 2065 originally have an airflow sensor? Later DEC big-iron style machines (even if not actually big iron, like the VAX 6000!), and even some small machines (like the 11/44) did. Lack of airflow means that a self-heated thermistor gets hot, which trips power.

Admittedly when you have a lot of little fans it's harder to do the airflow sensor thing than when you have a single humongous three-phase blower.
Tim Shoppa, Bad Example
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Posted 9/19/2005 8:26 AM
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2060s had a air (or maybe temperature) sensor. I remember one of our operators crashing the machine by just leaning on it for a while (this was the back of the CPU bay by the power supplies).

There was an over-ride toggle switch. You might want to double check it.
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