Hi Gran, >On Superstition mountain in the Imperial Valley we have a S-COM 5K that has taken repeated dumps after power line failures. The controller is running off an Astron 35A supply. By dump I mean the only problem is that the controller has to be re-programmed after the AC power line failure. Now I know there are other ways than than the 13.5V for a glitch to get into the controller but I would suggest power to be the most likely. The battery to hold up the memory has been replaced.
The 5K has a 15V Tranzorb across the 12V power input to absorb that kind of spike. Even without it, the power input feeds a 10V regulator which feeds a 5V regulator, and there's lots of bulk capacitance on both. No spike should be making it into the logic innards. Try powering it from a different source and cycle the power to see if memory is maintained. My guess is you'll continue to see the same problem. I'm suspicious about the memory backup even though the battery was replaced. Could it be that this unit has a DS1643 in the RAM socket? Many 5K owners did the V2.0 upgrade (which involved swapping the coin cell and supervisor IC with a DS1643 RAM/battery/clock module) and left the old coin cell on the board. If so, replacing the coin cell won't do anything. If the 5K still has the older discrete RAM/battery arrangement, there's a push-on jumper to interrupt the memory power that should have been pulled to replace the cell. Was it put back in? If the 5K has the V2.0 mod, IC-9 is gone and there are two horseshoe-shaped wire jumpers in its socket. Be sure they're making good contact (they were soldered if we did the mod). The COR, CTCSS, PTT and audio circuits are pretty well buffered with respect to the outside world and I would agree that they're not likely the problem. 73, Bob Bob Schmid, WA9FBO, Member S-COM, LLC PO Box 1546 LaPorte CO 80535-1546 970-416-6505 voice 970-419-3222 fax www.scomcontrollers.com **************************************Check out AOL's list of 2007's hottest products. (http://money.aol.com/special/hot-products-2007?NCID=aoltop00030000000001)
