chad@norge.dec.com (06/23/89)
Hi! I've just started to monitor this group again, after a long absence. I am not a hardware hacker with any knowledge of building my own circuits or logically knowing why a problem might exist, but I do take the soldering iron to hand now and then for simple progects. I figured out with a little help from you folks over a year ago ho to DIY 520STFM memory upgrade -- my only problem was a short that a friend of mine found :-( :-). I also swapped out the ss drive mech. and replaced it with a ds drive mechanism. That is the extant of my being able to figure things out. Here is my current problem. I was recently able to get an old style 520 with mono monitor and SF354 external ss drive for $200. It had a trouble booting but upon reseating the cchips seemed to work fine. Unfortunately however, it doesn't work now. These are the symptoms -- drive and monitor on, normally formatted ss floppy in drive. Switch computer on. Screen goes white for about twenty seconds and then the mouse pointer appears but there are no icons. (as if the drive were off or no disk in drive boot). When the computer is switched on the drive LED goes on for about 3-5 but the motor never spins. I have switched out with my good 520 STFM all the socketed chips one at a time and tested the old 520. It still has this problem. (I switched out the two square chips [glue and the other one], one chip that looks custom but is in conventional ic packaging and 3 of the ROMs). I cannot afford to have this professionally fixed so am appealing to the USENET community for ideas of what could be the cause of the problem and possible fixes. I am not adverse to replacing soldered chips. Oh yeah, I also checked the cardboard spacer betweenthe motherboard and the bottom metal shielding for shorts, nothing to be detected. Any and all help appreciated!!! either post or email. check above path for email. Chad chad@norge.dec.com