Re: Equipmet to trace Ethernet signal



Could be, but there is nothing like V-Lan or subnets around as there is no yet IP layer, the phone cryout "No Ehternet" it means

1) Connection problems - Jack, Cable, bended pins
2) Receiving tranfomators on the motherboard are out of order, some capasitors are in short ciurcuit, or metal path is destroyed... as result Ehternet electrics do not reach to IC pin

So need advice how to visualize Ehternet pulses, how to trace its track over motherboard...

Re: Equipmet to trace Ethernet signal



There is no IP address yet, no routers or firewalls. My home PC Ethernet adapter cable goes to PoE injector and goes to the phone. PoE comes via 7-8 and 4-5 pair, it works fine, -48 V comes to phone's motherboard, the phone display and buttons LED are working....

Re: Equipmet to trace Ethernet signal



The phone is pretty old and there is no WI-Fi option. I also worked hard with the input Ethernet jack, I am sure the cable connectivity is OK. I would like to trace Ehternet frames further, over the motherboard. I need to be sure that those frames really reach to the IC pins....

Re: Equipmet to trace Ethernet signal



Here is what I do to force the Ethernet IC to start transmitting: I disable and enable Ethernet adapter in "Change adapter option" window. As soon as I hit the button "Enable" I immediately see some very low AC voltage right at the transmit pair. After some time, the voltage disappears and then comes back, it is about 0.2-.4 v measured by standard multimeter. I suppose I see a broadcast Ethernet frame, something like ARP request. So, it is really possible to get some transmission in the cable even without...

Re: Equipmet to trace Ethernet signal

The phone has imbeded startup procedure. When you plug the Ethernet/PoE cable to the phone jack it starts to boot and writes some messages on the screen. After several minuties the phone writes: "No Ehternet" wich sipmply means the phone does not get any Ethernet frame from cable. Surely I have checked all possible connection issues. I finaly disassemebled the phone and looked inside - all electrical contacts seems to be fine, there are connections from input RJ45 pins to the motherboard. First they go to input transformers 1000 BASE...

I have Avaya 9641G IP Phone wich reports "No Ethernet" on the screen during initial start. I have intention to trace an Ehternet signal from the very input RJ45 jack throuth the phone mptherboard to the Broadcom communication CPU input pin.
Need youe advice how to: first I have suggested to buy an oscilscope, but not sure what to select, the pro version may become too expencive, and basic version may not capture high frequesncy signal. I really don't what to spend a fortune just for the pleasure to see the Ethernet frames. I also considered to measure just an AC voltage at the...

Re: Delta TDPS-138AF Avaya no output repair

Just successfully repaired Avaya IP 500v TDPS 138. I was extremely lucky, the reason was easy to find: the fuse burned out, and checking the AC input resistance showed an asymmetric value depending on the polarity of the tester. Comparison with a working module also confirmed that faulty part is somewhere in the input circuit. Suspicion fell on the diode bridge, and indeed, when I soldered out the GBU8K chip, one of its diodes was in a short circuit. Replacing of the diode bridge restored the operation of the unit.

Re: New Members - please post your introductions here

Just trying to introduce myselves... not sure I am doing this correct way. Sorry than.
I am here to fix Avaya IP500v2 power supply
TDPS 138AF