From: ohland@charter.net   
      
   95 XP Op Panel - Hidden Remote IPL Switch (SW1)   
      
   What's the switch SW1 for on the op panel PCB?   
      
   Tom says:   
       The SW1 switch is normally hidden behind the Op Panel Bezel.   
   Contrary to what has been said about it not having any function in the   
   Model 95, based on its wiring and some testing I have determined that it   
   enables/disables the "Remote Power-ON" feature.   
       This allows the system unit to be turned on and off from an external   
   source - via the J4 pin header on the planar board. For this to work the   
   hidden SW1 switch must be pressed down, and then it's possible to power   
   the system on by grounding pin 2 of J4, and power it off again by   
   removing this connection. The system will power down only if the main   
   power switch (SW2) remained in the OFF position.   
       The J4 connection would be realized using an externally powered   
   electronic switch - relay, semiconductor etc. The control signal could   
   be then supplied from a device connected to a telephone line or some   
   other source.   
      
   Ed. Now we know its real name - Remote Initial Program Load (IPL) Switch   
   (source).   
      
   Tomas Slavotinek wrote:   
   > On 08.01.2023 19:57, Pertti Helander wrote:   
   >> I was at opposite end of PSU connector, didn´t notice the mark there.   
   >> When I closed PSU connector pins 1-2 with wire PSU fan starts.   
   >> But when I checked with multimeter PSU connectors all pins there was 0   
   >> V  with ground row pins and +- 5V or+-12V pins.   
   >> Between pins 1-2 there was 0 V not +5 V.  Is this OK?   
   >   
   > The voltage between 1 and 2 should be close to 5 V when the PSU is in   
   > stand-by. Since you have to tie it low (to ground) to power the unit on,   
   > 0 V is correct when the PSU is running.   
   >   
   > Here is how to measure the other voltages and what the expected ranges are:   
   > https://www.ardent-tool.com/85_95/Power.html#Primary_PSU_Voltages   
   >   
   > Also, Power Good (pin 16) should be at logic high (close to 5 V) if   
   > everything is ok.   
   >   
      
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