[Yaesu] FT1000MP Power Output Fault

Frank Davis fdavis@nf.sympatico.ca
Sun, 27 Apr 1997 23:18:23 +0000


Yesterday I posted a note about a problem that started yesterday with my MP.
Upon further checking and observation it is evident that the cooling fan has stopped working.
It doesn't come on at all.

1) Can anyone out there measure the temp over the final heat sink at which the fan cycles 
on and off??  Its easy to stick a thermometer in the openings at the back and measure.

2) My rig has the following heat characteristics:  Measured by digital therm [probe stuck in a slot
                                                   over the PA heat sink]   
    -Cold start     74.5F  RX mode
    -at 3 mins      76.3F    "
    -at 8 mins      79.4F    " 
    -at 12 mins     80.3F    "
    -at 14 mins     81.5F  sending TEST CW @ 50W
    -at 16 mins     82.6F          "    
    -at 18 mins     84.2F   RX mode   
    -at 19 mins     85.0F  Trouble starts here....With MOX on it sounds like a make and break scratchy 
                                                  opening of a marginal connection or component.
    -at 24 mins     88.8F  MOX ON                                      "	
    -at 27 mins     91.7F  full failure of output - power now 2-3 W
    -at 30 mins     93.0F  Stays at this temp (in RX mode) for beyond 30 mins.

3) The rig block diagram shows a control line coming from the Power assembly for the fan.
   If you have the schematic of this unit...doed it show what is on this control line?

4) Several reasons why the fan is not working
	1.  Fan burned out
	2.  Not getting voltage from the regulator unit
	3.  Not getting control signal from the PS ASSY FAN CTL line.
	4.  Not getting a call for cooling signal from the PA unit.


Could the build up of heat be causing this problem of that I described yesterday and above.?
Any commenst would be appreciated.

73
Frank VO1HP

--
FAQ on WWW:               http://www.qsl.net/k7on/yaesu.html
Submissions:              yaesu@contesting.com
Administrative requests:  yaesu-REQUEST@contesting.com
Problems:                 owner-yaesu@contesting.com