MORSE@NSFVAX.BITNET (01/08/86)
We are having a problem with our VAX that DEC cannot solve. Perhaps someone on the net has some information? We have a VAX 785 running VMS. It has two DHU11's. Terminal access is at 9600 baud and goes through a MICOM 600 port selector. What happens is that one of the ports refuses to accept characters, meaning you cannot log on to it. After every character (or couple of characters) the port transmits an X-off to the terminal, and the terminal refuses to transmit anything more to the VAX. The user sees the Username: prompt, but after the first character of their username is echoed back, it appears as if everything is hung. If the terminal is set to ignore the X-off, the user can log on and the session is completely normal except that the VAX continues to send X-off's every few characters. This appears pretty infrequently, but usually one line will go weird within a week after a boot, which seems to clear up the problem. Once a line exhibits the problem, it remains that way until a system boot. The problem does not hit one particular line, it seems relatively random. Anybody every see this before? Any ideas? It's getting to be a pain to disable the ports at the port selector. DEC has pretty much given up, although they suspect it is something the MICOM is doing. Thanks in advance, Mike Morse National Science Foundation BITNET: MORSE@NSFVAX CSNET: MORSE@NSF
info-vax@ucbvax.UUCP (01/08/86)
Runing a 750 we had the same problem with a dz. It truned out to be a combnation of things. The unibus had a flaky pin that woudl short to the one next to it. This would cause spiks to be sent through the board (after a spike we could not talk to the bord.) This eventualy damaged the bord. DEC replaced it several times. After a coupel of trys we put it in a diffrent slot. Dec eventuraly gave us a new backplane because we had trouble with another slot. It took 2 years to get every thing fixed. Good luck.