trw@usna.NAVY.MIL (tsmith <trw@usna>) (03/25/90)
Well, a small disaster has occured. I shutdown my 7300 last night to prepare for an upgrade from 2.0 to 3.5 and when I turned the power back on, nothing. The screen come on with a typical pattern but there is no disk activity (hard or floppy) and the machine just sits there looking dumb. I checked the LEDs and the green one lights but there is no other activity. Anybody have any idea what I should be looking for??? I have another machine to use in the meantime but I would really like to get this one working again as I have put a lot of software on it. At the same time could someone tell me if anyone has looked into replacing the 64K memory chips with 256K chips? I seem to remember that the only real difference in the chips is pin 1 (on 64K chips it is NC and on 256K chips it is A8.) It would be nice if I could put 2MEG on the motherboard. And maybe even on the expansion board as well. One more question before I go back and stare at my poor 7300. If I can't revive my dead machine, is there any way I can use the expansion memory in my other machine (making it 1 1/2MEG)?? And what about putting a second disk drive on it? I have a case and power supply I could use to house it externally but can I hook it up somehow?? Thanks for any help anyone can provide. bill gunshannon trw@cad.usna.mil 720wfg@scrvmsys.bitnet bill@platypus.uofs.edu (They are all valid addresses to reach me. Of course, there used to be mordor!bill@platypus.uofs.edu, but he's not feeling well at the moment. :-( :-( :-( )
yarvin-norman@CS.YALE.EDU (Norman Yarvin) (03/28/90)
In article <221@usna.NAVY.MIL> trw@usna.NAVY.MIL (tsmith <trw@usna>) writes: >dumb. I checked the LEDs and the green one lights but there is no other >activity. Aha! From the reference manual: red yellow green red failed... off off off on telephone initialization off off on off video RAM test <------------------------ off off on on map RAM test off on off off to set map RAM to unity map off on off on dynamic RAM test off on on off initialization off on on on to find loader Suggestions: the usual -- power cycling, dusting it out, reseating cables and chips. The video RAM seems to be 4 4416 chips at positions 17A, 16A, 15A, 14A if I'm reading the schematics right. >At the same time could someone tell me if anyone has looked into replacing >the 64K memory chips with 256K chips? I seem to remember that the only real >difference in the chips is pin 1 (on 64K chips it is NC and on 256K chips >it is A8.) It would be nice if I could put 2MEG on the motherboard. And >maybe even on the expansion board as well. It has been done; refer to jbm@uncle's HWNotes (archived at osu-cis.) Norman Yarvin yarvin-norman@cs.yale.edu