10 Mar
2007
10 Mar
'07
10:01 a.m.
On Fri, 9 Mar 2007, Jay West wrote:
I was looking at the power control board for the H742A
(5409730) that is
supposed to be putting out my +15v. I couldn't find any schematics on this
board but the system engineering prints appear to indicate they should be
present. In the absence of schematics (and any obvious scorching) I figured
I have the complete set that came with my 11/45. The schematics are on
the sheet titled "POWER CONTROL BD.", number 5409730-0-1.
And I had exactly the same fault in my H742 during operation. The fan was
stuck so the transistor and other parts got really hot...
1) The critter is Motorola "DEC3000" which
I'm betting is a DEC house part
number (since ECG xref shows nothing && it starts with DEC). Can anyone clue
me in to what part that really is?
Both the transistor and the schematics say Motorola MJ3000.
Please also check the zener D3, a 1N5353B (16V) that is connectec between
the base of the transistor and ground. I guess it is shorted.
2) Are the schematics for 5409730 around so I can try
to understand it a
little better?
Yes, I'll try to scan it (not easy because of the paper size).
Christian