du4@mace.cc.purdue.edu (Ted Goldstein) (08/11/90)
(Got no answers first time, so posting again with wider distribution) I have an original IBM PC that gets PARITY CHECK 2 errors when running certain applications, but is not reproducible by any exact sequence. Now for the frustrating part: the PC passes startup test okay, all 3 of my memory test programs can run all day without error, and all the memory chips on the expansion board pass ok on my chip tester. Now for the question: I know PARITY CHECK 2 refers to an error on the 'I/O channel', but does this necesarily refer to a memory board or could it be from another card such as the hard disk controller or video card? If it _is_ the memory card, I guess it must be due to something other than a faulty memory chip. I do not have another memory board to swap in right now, but I know that would be the thing to try. Any ideas or suggestions on how to track down this problem, or on what exactly can cause PARITY CHECK errors? ADVthanksANCE -- Ted Goldstein E-mail: du4@mace.cc.purdue.edu Network and Systems Admninistrator Phone : (317) 494-9070 Purdue University School of Technology Office: Knoy Hall, Rm G009 Philosophy's alright, when you have a house to think about it in-Arlo Guthrie
grege@gold.GVG.TEK.COM (Greg Ebert) (08/11/90)
In article <5310@mace.cc.purdue.edu> du4@mace.cc.purdue.edu (Ted Goldstein) writes: > >Any ideas or suggestions on how to track down this problem, or on what >exactly can cause PARITY CHECK errors? > I'll hazard a guess that it's creeping-in through IO_CHANNEL_CHK. Try taping-off pin A1 with clear tape, on each card on an individual basis. Maybe you can start-out by removing cards not required for boot.
davidsen@crdgw1.crd.ge.com (William E. Davidsen Jr) (08/14/90)
In article <5310@mace.cc.purdue.edu> du4@mace.cc.purdue.edu (Ted Goldstein) writes: | I have an original IBM PC that gets PARITY CHECK 2 errors when running | certain applications, but is not reproducible by any exact sequence. | Now for the frustrating part: the PC passes startup test okay, all 3 | of my memory test programs can run all day without error, and all the | memory chips on the expansion board pass ok on my chip tester. *if* the programs in question use the floppy, memory access via the DMA channel may be using diferent timing that the CPU. You might also try playing with the refresh time, slowing it down until you get parity on a few chips and pulling them. This sometimes works when nothing else will. This comes to mind because there was a refresh time diddler posted to cbip a few days ago, and a more complete version will be posted shortly. -- - bill davidsen (davidsen@crdgw1.crd.ge.com) GE Corp. R&D Center; Box 8, KW-C206; Schenectady NY 12345