23 Mar
2007
23 Mar
'07
8:06 p.m.
Hey, that thing is hard to get to! Someone tightened down the screws in the
back that hold the regulator in place, so after undoing the two screws in
front it still won't slide out. Is there a trick to this? Do I have to take
the whole supply out? Can't get a screw driver in there with the upper H742
in place :\
Suggestions appreciated :)
Jay
24 Mar
24 Mar
4:34 p.m.
Hey, that thing is hard to get to! Someone tightened down the screws in the
It's a right pain, isn't it!
back that hold the regulator in place, so after
undoing the two screws in
front it still won't slide out. Is there a trick to this? Do I have to take
the whole supply out? Can't get a screw driver in there with the upper H742
in place :\
Getting the H742 supplies out is a pain too, due to the fan wiring. You
have to unbolt the fans, drop them into the space where the 'bricks' go,
and then disconenct the wiring from each fan.
I seem to remeber unscrewing the _top_ H742 supply from the rack and
moving it out of the way without disconnecting the fan wires (I think I
had to unplug some of the mate-n-lock connectors). Then I could get to
the screws in the lower supply.
There are, of course, screwdrivers designed to work in such spaces,
including ones with bevel gearboves in them. Is it possible to use
something like that to get at said screws?
-tony
25 Mar
25 Mar
5:47 p.m.
Tony wrote....
It's a right pain, isn't it!
...snip...
Getting the H742 supplies out is a pain too, due to
the fan wiring.
...snip...
I seem to remeber unscrewing the _top_ H742 supply
from the rack and
moving it out of the way without disconnecting the fan wires (I think I
had to unplug some of the mate-n-lock connectors). Then I could get to
the screws in the lower supply.
I found a way without removing all the fans...
a 2x4 from side to side in the bottom of the rack, under the back half of
the bottom H742. Then a few wood shims directly under the regulator tray.
Then put a small 2x4 in front (and a wood shim or two) between the H742 and
the 861. Disconnect all the plugs on the supply and unscrew all the fastners
on the cables and the supply. Then you can slide it gently on the wood to
the middle of the cabinet and you can easily get to the guts of the power
control board. The power harness stays attached to the fans but can move
with it if you undid all those fasteners too. A heavy screwdriver under the
front, twisted slightly, to align the holes for rebolting it into the rack.
Phew. Now that I have the entire regulator board out, I can visually see the
fuse F1 is clearly blown (and of course it tests open). I could just replace
it, but something obviously caused it to blow. Once I put a new fuse in if
it doesn't blow, what should I be looking for in that circuit? Also,
couldn't I just plug 20-30vac from a bench supply into this linear supply
and then check test points in the circuit? Given it's hard to reach
location, that would make it easier to work on if it could be powered up on
the bench.
Jay
6:56 p.m.
Phew. Now that I have the entire regulator board out,
I can visually see the
fuse F1 is clearly blown (and of course it tests open). I could just replace
it, but something obviously caused it to blow. Once I put a new fuse in if
Well, IIRC, there's no current limiting in this supply. If F1 ahs blown,
the fault could be a problem in whatever this supply is feeding (and not
on this board at all).
it doesn't blow, what should I be looking for in
that circuit? Also,
couldn't I just plug 20-30vac from a bench supply into this linear supply
and then check test points in the circuit? Given it's hard to reach
Should be fine.
-tony
6481
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