Path: news1.icaen!news.uiowa.edu!news1.chicago.iagnet.net!qual.net!iagnet.net!howland.erols.net!news-peer.sprintlink.net!news-backup-east.sprintlink.net!news-in-east.sprintlink.net!news.sprintlink.net!Sprint!151.164.30.38!newsgate.swbell.net!swbell!not-for-mail From: Rubywand Newsgroups: comp.sys.apple2 Subject: Re: Slots not working Date: Fri, 20 Feb 1998 04:01:57 -0600 Organization: Southwestern Bell Internet Services, Richardson, TX Lines: 39 Message-ID: <34ED5495.D940E49B@swbell.net> References: <19980220051700.AAA25108@ladder03.news.aol.com> Reply-To: rubywand@swbell.net NNTP-Posting-Host: ppp-207-193-8-177.hstntx.swbell.net Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Trace: (null) 887968850 19553 (None) 207.193.8.177 X-Complaints-To: usenet@nnrp3 X-Mailer: Mozilla 4.04 [en] (Win95; I) Xref: news1.icaen comp.sys.apple2:130451 Supertimer writes ... > > I had a ROM 1 GS motherboard which worked fine except the slots > did not work. When a card was plugged in and the control panel was > set to YOUR CARD, the slots were still seen by the GS as empty. > ALL the slots had this problem EXCEPT the memory expansion slots. > What was wrong with this motherboard? If you are saying that, whatever the card and whatever the Slot, the cards plugged into the GS's Slots did not work, then, there are a few halfway decent suspects on a GS that, otherwise, seems to work okay: 1. A break in the trace which is supposed to supply +5V to each Slot card would shut down nearly any Slot card. 2. Most Slot cards need to receive and/or send information over the Slot Data bus. A defective 74HCT245 (IC UF2) or one with a loose/broken pin connection would be likely to kill Slot Data bus transfers. 3. A defective Slotmaker chip (IC UE11) or one with a broken trace on any of several inputs would render most Slot cards non-functional. 4. A break in any of several traces supplying signals to the Slots would disable many Slot cards. 5. Many Slot cards would not work should any of several Slot traces be shorted to another trace or to ground. (Sources of shorting include bent case shielding below or behind the motherboard, a Slot socket into which a shard of metal, solder, or bit of wire has fallen, a shorted bypass capacitor, and, possibly a Coke, etc. spill leaving conductive residue beneath several Slot sockets.) 6. If a defective Slot card is plugged into one Slot while other Slots are being tried with other cards, the defective card could short or corrupt critical bus lines and render other cards non-functional. Rubywand