SYNFUL@DRYCAS.CLUB.CC.CMU.EDU.UUCP (11/17/87)
Hello! Remember me? I'm the one with the little uVAX that could...well
sometimes anyway.
I thought I'd pass on some useful information as well as a little FCO
humor. This is regarding to a common problem in uVAXen regarding the
cable which goes from the power supply to the backplane.
It's a little old (and the humor part of it is a little long), but it
might be useful to some.
----------
Field Change Order Number: BA23-I001
Applicability: Applies to all BA23-AX and BA23-BX boxes.
Problems/Symptoms: DC Power Cable, P/N 70-20450-01 over-heats during
normal use. The current rating of the components has been derated by
the manufacturer and the cable does not meet the requirements of the
unit. The DC Power Cable has been replaced with P/N 17-01311-01.
This FCO incorporates ECO 70-22380-MK002
Quick Check: Check for P/N 70-20450-01 on tag of the DC Power Cable.
FCO Release Date: 05 December 1986
[here's the long part you may want to skip]
INSTALLATION INSTRUCTIONS
1. Obtain the customer's permission to take down the system. Then power
down the system via the console switch.
[In a large *-bordered box:
CAUTION: AC POWER MUST BE REMOVED FROM THE SYSTEM BEFORE PROCEEDING]
2. On the cabinet type system, remove the AC power by setting the 874
power controller circuit breaker to the OFF (0) position. To gain
access to the circuit breaker, remove the back cover. The circuit
breaker is located on the bottom left.
On the pedestal type systems, the power cord must be removed from the
power receptacle, after powering down via the console switch.
3. Gain access to the DC Power Cable by doing one of the following:
a. On cabinet systems, slide the box forward until the front top
cover is completely exposed so the screws can be removed to gain
access.
[In a box: CAUTION: DO NOT SLIDE THE BOX OUT OF THE CABINET UNLESS THE CAB
IS BOLTED TO AN ADJACENT CAB, OR THE STABLIZER LEGS ARE EXTENDED.
ONLY ONE CABINET IS ALLOWS TO HAVE AN OPTION OR BOX PULLED OUT AT ANY ONE
TIME.]
b. On pedestal systems, remove the front and rear covers. Then
remove the front chassis retaining braket, and push the subsystem
forward until the front top cover is completely exposed, so the
screws can be removed to gain access.
[Boxed: NOTE: THE MODULES IN THIS SYSTEM CONTAIN ELECTROSTATIC DISCHARGE
SENSITIVE DEVICES. THE USE OF THE VELOSTAT KIT IS ESSENTIAL TO PREVENT
DAMAGE WHICH MAY NOT BE NOTICED IMMEDIATELY]
4. Set up the VELOSTAT kit P/N 29-11762 in the following manner:
a. Unfold the VELOSTAT mat to full size.
b. Attach the ground cord to the snap fastener on the VELOSTAT mat.
c. Attach the alligator clip end of the ground cord to a good (bare
metal) ground on the system.
d. Attach the wrist strap to either wrist and the alligator clip to a
convenient portion of the mat.
5. Remove the front top cover.
6. Remove the fan cowling if present.
7. Disconnect the DC Power Cable from J9 on the power supply and J1 on
the signal distribution panel.
8. Install new DC Power Cable included in the EQ kit.
9. Reinstall the fan cowling if present.
10. Reinstall the top cover.
11. Slide the subsystem back into the pedestal or cabinet depending on the
type system you have.
12. For the pedestal mount reinstall the front chassis retaining bracket
and the front and rear covers.
13. Power up the system by one of the following procedures:
a. For the Cabinet style systems, turn the 874 power controller
circuit breaker to the ON (1) position. The breaker is located at
the rear of the cabinet on the bottom left. Replace the back
cover of the cabinet. Turn the power on from the console switch
and let the self test run to completion. It must run successfully.
b. For the pedestal systems, plug the box into its power receptable.
Turn the power on from the console switch and let the self test
run to completion. It must run successfully.
14. Update the Site Management Guide to reflect this FCO.
15. Report LARS data as per example.
---End of included FCO text---
Notice, in step 8, the whole "installation" step is basically connect the
new cable. 11 steps to take down/take apart/put back together/bring up
the system, one (more descriptively) on how to take the old cable out, and
a simplistic step on how to put the new one in.
It wouldn't be bad, except the new cable looks like this:
cnctr
+-----+
+-----+
| | | connector
| | |+-------------+
| | |+-------------+
| | | | | | | | | |
| | | | | | | | | |
+------------+ | | |
+------------+ | | |
connector | | |
+-----+
+-----+
cnctr
If plugging this into two slots is intuitive to anyone, I'd be surprised!
Oh, well...sorry for the length.
--Marc Shannon
Carnegie-Mellon University