pochron@cat30.cs.wisc.edu (David Pochron) (05/02/91)
In article <1991May1.112820.22292@uservx.afwl.af.mil> ridout@uservx.afwl.af.mil writes: >Well if finally happend. My Amiga 2000 is broke :-(. >I touched my mouse or joystick with a good static charge and now my clock is >going nuts. it counts up at the rate of days per second. The big thing is I You undoubtedly zapped the 8520's...Replace them. They are located right under the power supply, towards the back of of the machine. Now, on a slightly different subject... A while ago I posted about how I fixed my clock problem by replacing the 8520's with older ones from an A1000, but got no response. I'll try again... What is the difference between the RS series of 8520's that are found in the A1000, and the A-1 series, found in the A2000. I tried several 8520A-1's in my 2000 and none would fix the problem of my haywire clock, but, when I use the older 8520RS' chips from the 1000, the A2630 card likes them just fine. Any ideas? >| Brian Ridout What's the difference between a CAR | >| PL/SCEV salesman and a COMPUTER salesman? | >| Kirtland AFB NM 87117 *** | >| ridout@uservx.afwl.af.mil The CAR salesman KNOWS when he's lying! | -- David M. Pochron | Transparent DWV pipe: For the man who wants to | see it all... pochron@garfield.cs.wisc.edu | (If you don't know what DWV is, get a life! :-)
daveh@cbmvax.commodore.com (Dave Haynie) (05/03/91)
In article <1991May2.154402.1259@daffy.cs.wisc.edu> pochron@cat30.cs.wisc.edu (David Pochron) writes: >Now, on a slightly different subject... >A while ago I posted about how I fixed my clock problem by replacing the >8520's with older ones from an A1000, but got no response. I'll try again... The older 8520s have a significantly lower output current on the "B" port, and there are some internal pullups removed. The output strengths were increased in order to eliminate some problems that had been seen with printers during the A1000 days. While I think the old 8520s will function in an A2000 or A500, you don't want to put a new one in the A1000, some lines will float. >I tried several 8520A-1's in my 2000 and none would fix the problem of my >haywire clock, but, when I use the older 8520RS' chips from the 1000, the >A2630 card likes them just fine. Whatever your clock is doing, it sounds to me like your real problem is with the TICK clock coming from the power supply. I take it that your run-time clock isn't acting reasonable. That can be an 8520 failure, I had one die on me this way once. It can also be a problem with the TICK input to the 8520. You can change J300 to use the VSYNC* line instead as a timebase, and see if the newer 8520 still shows a problem. It's very possible that, assuming something is different on your TICK line, it's a marginal thing that just happens to be seen by one series of 8520 and not by the other. While the old part shouldn't be a problem, other than on long printer cables (and it may be a tad easier to zap), it's usually a good idea to solve a problem rather than just work around it, when you have the chance. > David M. Pochron | Transparent DWV pipe: For the man who wants to -- Dave Haynie Commodore-Amiga (Amiga 3000) "The Crew That Never Rests" {uunet|pyramid|rutgers}!cbmvax!daveh PLINK: hazy BIX: hazy "That's me in the corner, that's me in the spotlight" -R.E.M.