From: doug.mccomber@fakepart.gmail.com   
      
   Mark Whitlock wrote:   
   > Knut Roll-Lund wrote:   
   >   
   >> Doug_M wrote:   
   >>   
   >>> Hi, I have a 4D with an Astec power supply.  The power supply "sizzles"   
   >>> first for about 30 seconds before the system comes on.  Once it is   
   >>> warmed up it turns on immediately.  The person I bought it from sent me   
   >>> a replacement Astec power supply.  That was some time ago.   
   >>>   
   >>> I only just got around to swapping out the old supply for the new.  When   
   >>> I turned the system on there was nothing, no sound, smoke, smell, spark,   
   >>> etc. and neither the monitor or drives come on. Completely dead.   
   >>>   
   >>> I thought maybe the new Astec supply was dead, so I put the old one back   
   >>> in.  Same thing.   
   >>>   
   >>> I've got a multi-meter but I really don't know what I'm doing with it   
   >>> (just bought it, don't know much about electronics).  I check the on/off   
   >>> switch, and it works. I check the wires from the switch to the power   
   >>> supply and they're live.  I checked the posts on the power supply and   
   >>> they are live too.  So are then leads to the mobo and CRT.   
   >>>   
   >>> I'm stumped.  Any hardware gurus out there that can point me in the   
   >>> right direction?   
   >>>   
   >>> Thanks,   
   >>> Doug   
   >>>   
   >>> PS  Both the CRT and PS fuses are good too.   
   >>   
   >>   
   >> Try wriggeling (check) the cables to the video card (might have been   
   >> pulled slightly when opening it...). The edgeconnector there is quite   
   >> loose both on my III and (regular) 4.   
   >>   
   >> Knut   
   >   
   > Doug,   
   >     The leads to the mobo & crt are they 5VDC & 12VDC + or -   
   > 1/2 volt? Your meter should have a DC & an AC setting. the DC   
   > may be marked by a long line with dashes underneath .and the   
   > AC may be marked by a sine wave. Check the molex connector   
   > (that rectangular white thing with 4 holes) on one setting (DC)   
   > then on the other (AC). The readings should be 5 & 12 DC   
   > this shows the regulator is working ,and 0 AC this shows the   
   > rectifier is working (may depend on meter). The "sizzling"   
   > bothers me ,are you sure this was from the power supply and   
   > not the (video board) flyback transformer ?   
   >     BE VERY CAREFUL WITH THE TOP OPEN the CRT may have   
   > 5000 volts on it WHETHER ON OR OFF !   
   > Stay away from the CRT it is not always your friend.   
   >     Please get back to us ,The first sign to look for   
   > is the filiment in the back of the CRT tube ,It should   
   > be glowing orange (near the end of the tube where it plugs in).   
   > Certainly we can narrow this down some.   
   > Hopefully helpful,   
   >     Mark Whitlock.   
   >   
   Mark, thanks for the Multimeter help.  With the molex connectors off   
   (there is a small two hole one as well) I get the correct voltages. I   
   found Frank's earlier post and so I checked all the grounds (I have no   
   peripherals connected).  No luck there.   
      
   So I checked the voltage at the end of the black connector to the video   
   board.  Despite get 12 at the poles (with the big molex off too), when   
   the molexes are connected, I only get about 1 volt at the black connector.   
      
   So I took off the small molex, left the large one on, and checked the   
   voltage at the poles.  Again only about 1 to 1.5 volts.  I tried   
   unplugging the connectors to the motherboard and conducting the same   
   test, still only 1 - 1.5 volts.   
      
   The large molex looks ok.  I've tried different power recepticles and   
   inspected the power cord/plug itself. And again, what is really puzzling   
   is that nothing is getting power, at least there is no indication.   
      
   Thanks to everyone for all their help.  Any more ideas?! :)   
      
   Doug   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)