davidy@sumax.UUCP (David L. Yee) (11/21/90)
Well, at long last I can say the GVP Series II HD controller/RAM problem is licked. After this, I do not want to hear the term "motherboard" or "resistor" for at least one month. :^) I finally bit the bullet and added the 470 ohm resistor (myself!) to U100 on the motherboard, and all went well. I had orginally taken it in to have the motheboard upgraded, but when I got it back, nothing! Needless to say I was depressed and verging on madness, but I called GVP up and they faced me resistor mod instructions, and now life is good. To possibly help others who face this problem, I offer the following: 1. This affects A2000 motherboards 4.x (mine was 4.3.) Not all suffer this problem. If yours does, the first thing you should check out is to see if you have a resistor at either U100 (on the right side of the 68000 facing from front to back, between the 68000 and the long resistor pack RP101) or one located to the right and near the top of the big plastic power supply connector. This location is called R5719. 2. Even if you have a resistor at R5719, it may be to no avail. It turned out I actually did have one, but it was no use. The folks at GVP told me to try this location first because it is much easier to get to when soldering. (Perhaps someone from Commodore, perhaps the esteemable Mr. Haynie, might wish to comment on this?) Anyway, I am guessing the reason the motherboard upgrade didn't work was because the tech saw that resistor their already and figured he didn't have to add the one at U100. But if you don't have anything there at all, it is certainly worth a try. 3. If the R5719 fix doesn't go, then bite the bullet and add the resistor to the U100 location described. The folks at GVP will fax you a diagram of what you must do (at least they did for me.) I STRONGLY recommend you obtain this diagram if you have any doubts where to solder. There is no clearly defined, silkscreened box for the resistor to go into (at least on my rev 4.3 motherboard.) Not wishing to part with any more of my precious Federal Reserve Notes, I soldered it in myself. It may be a case of fools going where angels fear to tread, but hey, it works now, and I'm not complaining. 4. Don't put too much stock in other remedies like swapping ROMS (from 1.2 to 1.3) or changing memory brands (I tried three different brands.) None of these worked for me. The grade A approved fix is to add the resistor, and they only cost .39 for five. (470 ohm, 1/4 watt.) If you can try the others obviously it may be worth a shot, but don't expect too much. Go for the resistor fix. Get GVP to send you instructions. Anyway, for the full scoop (technically) on this affair you should consult Dave Haynie's past posting on the subject ( who, BTW, I would like to say is one of the great, great friends of the Amiga community.) Try the R5719 fix if you don't have one- a fellow Amigan posted that this fix worked for him. But if all else fails, go straight to the heart- U100. David L. Yee Email to: davidy@sumax.seattleu.edu
davidy@sumax.UUCP (David L. Yee) (11/21/90)
Sorry for the waste of bandwidth, but Roger Dixon sent me email asking me to keep him in touch with the situtation. If you read this, I haven't forgotten! But all my mail bounced back when I tried to mail you. So if you need to reach me, please do so. David L. Yee Email to: davidy@sumax.seattleu.edu