lgs4

1. lgs4 is not powered on.
2. lgs4 is not connected to the ethernet.
3. lgs4 is unable to get its boot file from orthrus.

If lgs4 is on, but still not booting, make sure that the ethernet cable is connected between the motor controller rack e-net hub and the MAU box. Also check that the MAU box is firmly connected to the port on lgs4. Push the reset button on lgs4 to force a reboot.

If this fails, check and make sure the boot file still exists on orthrus. If it doesn't, you will have to retrieve it off an orthrus backup tape.

If all else fails, you can use a terminal emulator program on lgs13 to see what lgs4 is doing at boot time and where the problem may be. Information about connections and the terminal emulator program are on lgs13 (click on the lgs4 (alpha term) README.TXT icon).

1. Connect DB25 cable from lgs13 port 2 (should already have a DB9-DB25 converter installed in that port) to the lgs4 console port. Depending on which cable is used, you may need a null modem and/or gender changer.
2. Click on the lgs4 Alpha Serial Console Com2 icon on lgs13.
3. Push the reset button on lgs4 and watch the boot sequence. It can take up to a minute or two for the boot software to be downloaded and started. If lgs4 boots successfully, you should see a big VXWorks sign displayed, if not, note at which point the boot sequence failed to aid further diagnostics.

Frequent WFS Resets

No Signal from WFS Camera

Loader Errors

temperature -8 (or -7) errors are common and inconsequential. You can ignore these.

Bad control matrix errors happen if for some reason you run out of disk space or create a bad control matrix with the cm command. Just copy and old good control matrix into the new control matrix name to get rid of the error.

Traffic Errors

APD problems

• Make sure fibers are clean and well seated in APD and TT sensor.
• Identify if problem is a fiber or APD:
  1. Swap fibers between faulty quadrant and good quadrant at connection into APD black box.

     Quadrant Letter	Fiber Number	Data Cable Number
     A	1	0
     B	2	1
     C	3	2
     D	4	3

  2. If problem does not change quadrants, then the APD itself is likely the problem.
  3. If problem APD is still 'hot', make sure that all light is blocked from going into the APDs and there is no light leaking into the APD box (you can use the black AO shroud cloth to cover the APD box to block light if necessary). If quadrant is still 'hot', then dark current is high and the APD is almost certainly bad and needs replacement.
  4. If problem APD is still low, put a very faint light source into a good APD and bring up brightness until have high signal but far from saturating. Then plug this source into the problem APD quadrant to see if you get similar signal (this removes fiber throughput and alignment issues from the APD sensitivity issue). If still bad, then APD should probably be replaced.
     Note: Before replacing an APD, check voltages, as described below, to make sure that power supply or cable isn't the real problem.
  5. If problem did change quadrants, than there is probably bad alignment or bad fiber. Check LGS alignment document for info on checking alignment. If alignment checks out, then install a new fiber (it will have to be aligned, which can be time consuming).
• Check all voltages to APD: 10pin MS connector to 5V power supply.

  Pin	Voltage
  A,B,C,D	+5V
  E,F,G,H	-5V
  J	+5V Sense
  K	-5V Sense

• If voltages and cables check out OK, then install a new APD.