SatSig topic:

Modem boot problem

(Read 2962 times)

Jun 5^th, 2009 at 2:13pm

I've never seen this before... maybe I should have... but no dice on my end. I've loaded both a new IDS as well as option on modem and still same thing. This is what comes upin linux...

pc : [<001a1048>] lr : [<001a2b10>] Tainted: P
sp : bffdf968 ip : 00000000 fp : bffffe38
r10: 4039d1f8 r9 : 00000000 r8 : 0000b92c
r7 : 000003e8 r6 : 00013460 r5 : 40d55008 r4 : 00213b04
r3 : 00000000 r2 : 40d55008 r1 : 00213b04 r0 : 40d55008
Flags: nZCv IRQs on FIQs on Mode USER_32 Segment user
Control: 39FF Table: 03A74000 DAC: 00000015

IP address from new option I loaded does not reflect the modem. I did verify my option did take through linux via "cat falcon.opt" Unable to log into falcon due to the IP problem. Manually setting IP to what the modem is "showing." I'm able to load new package via TFTP this way.

It constantly restarts and when it does RX, TX, and Net LED's light up yellow and the status LED is red. After this little firework show It appears to startup normal... Power and Status LED green but then same ole same ole...

Tried giving as much info as possible even if it means nothing

Thanks in advance!

Jun 5^th, 2009 at 2:35pm

What version are you using (iDS)? Does it require a BSP? If so, did you load the BSP as well? That modem may have a kernel issue. hard to say.

Jun 6^th, 2009 at 8:45am

7.0.5... No BSP... It's no worries, instead of just sending it back broke I'm the kind of person that kind of likes to have an understanding. I'll keep an eye on the thread in case someone has an idea.

Jun 8^th, 2009 at 2:57pm

Duckhead

Please paste a bit more of the error message, a bit above and below. This is a Linux level operating system crash. You haven't given us enough to figure out what caused the crash though?

Jun 25^th, 2009 at 10:26pm

Sorry dot but that's all that comes up.... everytime the modem reboots that's all that's displayed. It's no worries, I have plenty of modems. I just like to get learned and try to fix them myself.

Jun 25^th, 2009 at 11:08pm

The reference to "Tainted" suggests a machine code error condition causing a CPU register dump. Since the software works OK on other modems the source of this may be a hardware fault on a connector or memory chip etc.

Using electrostatic discharge precautions look inside the box and check all connections, particulary socketed chips and the power supply cables. If there are socketed chips gently ease the chips up slightly and then depress back again carefully. Look for dry soldered joints with a magnifier lens.

The other thing to check is the voltages of the DC supplies. Low volts like 4.87 volt input (for a nominal 5.00 volt line) may well cause problems like you describe. If there are push-on connectors for the DC supply cables clean them carefully, make sure the springs work and use silicone contact grease to exclude oxygen and water vapour in future.

If you get the modem working normally again, and have no idea why, try gentle heat or freezer spray on each component to see if you can induce or clear the fault.
.
I've spend a lot of time fault finding VSAT modems that would occasionally reset over a period of months, later weeks or days, for no apparant reason. The problem gradually got worse. I plotted the DC voltage drop across the board DC power connector using a long memory millivolt oscilloscope to watch for changes. Gradually the voltage drop across the connector would increase, over many hours. The resistance would then occasionally drop instantaneously as microscopic corrosion points 'flashed' over. Over weeks, the zig zag voltage eventually reached a low of say 4.8 volts, at which point the modem failed. Power cycling often restored it to normal due the surge clearing the corrosion, but it would deteriorate again over next month till it failed again. The lesson learned was to use soldered joints or gold plated springs and gold plated pins for power supply cables. Good clean high pressure tinned contacts embedded in silicone contact grease does work OK.

Best regards, Eric.