domen@crin.fr (Eric Domenjoud) (09/14/90)
Everytime I have been using my ST for a couple of hours, it crashes. It seems that the bit 6 of odd addresses is turned to 1. just before the crash, black vertical lines appear on the screen. It is then impossible to reboot as long as the computer is warm. I brought it to the local ATARI dealer who was unable to make the phenomenon happen, but it still happens at my home, even if I boot my ST without anything: no hard disk, no floppy, nothing! Does anybody already had a similar problem and could say me what to do? Would it help if I changed the RAMs? My computer is a 520ST with 1M RAM. Eric
dmb@wam.umd.edu (David M. Baggett) (09/16/90)
In article <2700@loria.crin.fr> domen@crin.fr (Eric Domenjoud) writes: >Everytime I have been using my ST for a couple of hours, it crashes. >It seems that the bit 6 of odd addresses is turned to 1. just before >the crash, black vertical lines appear on the screen. It is then >impossible to reboot as long as the computer is warm. > >My computer is a 520ST with 1M RAM. Sounds a lot like a problem I've been having: the RAM upgrade board sits directly on top of the 68000, thereby preventing adequate ventilation. After a few hours of use I get all sorts of bizzare behavior (including the vertical lines phenonemon). I'm sure it's a heat problem because the 68000 is hot enough to burn my hand when the problems begin. Turning a fan directly on the 68000 "fixes" things. The MMU gets toasty too, which might explain your "bit 6" problem. Try running your ST with the top of the case off; the extra ventilation should alleviate problems like these. If that doesn't help, it's probably something else. Dave Baggett dmb%wam.umd.edu@uunet.uu.net
hardware@rose.uwaterloo.ca () (09/19/90)
Ok just so I dont have to write alot of Mail to everyone your ST isnt dead most likely its your internal power supply. The symptoms of a failing power supply, include having to reboot many times before normal operation, repeated bombs on bootup, erradic working one day and not the next, Lockup during ST operation. Of course there can be many other reasons eg bad ram chip etc. But from running a bbs for 5 years my number one problem was simply bad power supply. So to confirm this on a failing power supply or one thats about to go, get out your multimeter and check the power coming out of the leads going into your ST. If they are 8-10volts for the 12 volt line and 2-3 volts for the 5 volt line your power supply will act erradic if at all. PS NOTE dont play with your power supply without knowing something in electronic or you get a nice Zap or worse blow your keyboard chips. So if you are not techincally inclined borrow a friends ST for a day switch power supplies and see if that solves your problem. If it does you have two options buy a newly designed power supply from atari or fix your existing one. If you plan to fix your existing one you can start by replacing C12 or C13 large capacitors 2200 and 4700 pf and if that doesnt help I have replaced C11 and c12 on older model power supplies. If anyone has any questions leave me mail. Hope that helps. Hardware Dave at your Service