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
|