wtm@uhura.neoucom.EDU (Bill Mayhew) (09/02/90)
A while back, I started having problems with my Xerox 6064 machine, which is aa functional identical clone of the PC6300, built on the same Olivetti chassis. The only oddity of the Xerox 606x series is that they had verison 1.36 ROMs, where were 1.43 minus the EGA support. A call to the AT&T parts hotline (1-800-222-PART) got me 1.43 ROMs for about $35 (US). If anaybody needs the com code, drop me a line; when I ordered, they knew whata it was without the com code. Well on to the real subject. My machine has the LB series power supply. There are LA and LB supplies. Around December 1989, my machine started crashing every 20 minutes just like clockwork. Occascionally it would die with a partiy error, usually on my Intel Aboveboard, but occasionally the system board. Other times the machine would just lock up. A while back we received a service bulletin that mentioned that the connectors for the four pin disk drive on the power pack tended to develop cracks in the solder. I disassmbled the power supply and resoldered the drive connectors to the PC board. No dice. I still got the crashes. Finaally, I decided, "what the heck", and resoldered every joint on both the pc boards in the supply. After I did that, I've had no more spurious crashes since January. There weren't any obviously bad joints that looks like cold joints on either of the two boards, but re-flowing them did the trick. Don't mess with the internal parts of your power supply unless you know what you are doing. There is the possibility that incorect reassembly could cause a short circuit. There are high voltages inside the supply, so you should allow several minutes for residual charges to disipate before working on the power supply. Obviously, you should never attach the supply to a wall outlet with the cover ov the power supply removed. The supply will also not function correctly unless the output loads are connected. ==Bill== -- Bill Mayhew Northeastern Ohio Universities College of Medicine Rootstown, OH 44272-9995 USA phone: 216-325-2511 wtm@uhura.neoucom.edu ....!uunet!aablue!neoucom!wtm via internet: (140.220.001.001)