From: nospam@needed.invalid   
      
   On Thu, 7/3/2025 2:14 PM, Paul wrote:   
   > On Thu, 7/3/2025 9:13 AM, pinnerite wrote:   
   >> My main computer stopped working. Only built 18 months ago.   
   >>   
   >> My backup is 14-15 years or so old and has issues too.   
   >>   
   >> I decided to build a new backup machine, in most ways   
   >> identical to the first to allow for component substitution.   
   >>   
   >> I have a small Hakeeta powewr supply checker. I tested both power   
   >> supplies out of the cases and all the leds illuminated.   
   >>   
   >> After waiuting for all the components to arrive I started substituting   
   >> components. Nothing worked.   
   >>   
   >> Today I tested both power supplies, again out of the cases and   
   >> disconnected from all but the 20/24 pin power connector. This time, no   
   >> signs of life.   
   >>   
   >> What do I do now?   
   >>   
   >   
      
   An analog Hakeeta works a similar way.   
      
       LM311 ("is voltage greater than 4.75V") = logic output A   
      
       LM311 ("is voltage greater than 5.25V") = logic output B   
      
       Good_LED = A and NOT B             # This is the equation for "my voltage   
   is within 4.75V to 5.25V"   
      
   That's called a Window Comparator, and a window Comparator is   
   fashioned for each of the major supply voltages and drives   
   a LED if the voltage is "within the window".   
      
   As before, there should be a LED just sucking power from +5VSB,   
   as a basic status that the Hakeeta has enough power to run the   
   LEDs. If the plugged in and switched-on-at-the-back supply cannot   
   make +5VSB. all the LEDs on the Hakeeta Analog will be off.   
      
   LED1  "Hakeeta has power"   
   LED2  "+5VSB within window"   
   LED3  "+5V within window"   
   ...  and so on   
      
   The LM311 is an analog comparator, with a single digital output   
   indicating "greater" or "less than" for the two states it can   
   indicate. Additional logic gates are needed to do the A and NOT B   
   function.   
      
   But these days, a processor is cheaper than all that junky logic,   
   and the LEDs could just as easily be driven by a processor,   
   as for the logic board to have actual dollar-store LM311 on it.   
      
   At a minimum, the Analog Hakeeta can only work the PSU fans,   
   if the main 24 pin is connected. Just connecting a Molex 1x4   
   is not guaranteed to do anything. The Hakeeta has to ground   
   the PS_ON# on the main 24 pin, so the fans will spin and main   
   rails will come up.   
      
      Paul   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)