X-Received: by 10.182.52.199 with SMTP id v7mr40349723obo.36.1434391291210; Mon, 15 Jun 2015 11:01:31 -0700 (PDT) X-Received: by 10.140.101.22 with SMTP id t22mr372424qge.32.1434391291171; Mon, 15 Jun 2015 11:01:31 -0700 (PDT) Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!news.glorb.com!h15no3589301igd.0!news-out.google.com!k20ni1930qgd.0!nntp.google.com!z60no1374288qgd.1!postnews.google.com!glegroupsg2000goo.googlegroups.com!not-for-mail Newsgroups: comp.sys.3b1 Date: Mon, 15 Jun 2015 11:01:30 -0700 (PDT) In-Reply-To: Complaints-To: groups-abuse@google.com Injection-Info: glegroupsg2000goo.googlegroups.com; posting-host=46.138.106.255; posting-account=ywr7fwoAAAAOs7otmAvAPYzN8--GfV7P NNTP-Posting-Host: 46.138.106.255 References: <3b006148-d6eb-4d78-bd6a-4adad7ee8516@googlegroups.com> User-Agent: G2/1.0 MIME-Version: 1.0 Message-ID: <3b6dd76d-de7e-4ed6-b1ef-daa56d3ae3c4@googlegroups.com> Subject: Re: Reconstructing an AT&T 7300 From: vlaarom@gmail.com Injection-Date: Mon, 15 Jun 2015 18:01:31 +0000 Content-Type: text/plain; charset=ISO-8859-1 Xref: csiph.com comp.sys.3b1:361 On Friday, June 12, 2015 at 3:14:55 AM UTC+3, DoN. Nichols wrote: > On 2015-06-11, vlaarom@gmail.com wrote: > > Hello All, > > > I've found an at&t 7300 and disconnected floppy, hdd and display. When > > I power it up relays in modem are going crazy. > > > > Why the relays are going crazy? > > Well ... it is most likely the connector on the power supply. > You already have it apart, if you have all of those disconnected, so you > can look easily. > > Pull the wide single-row connector (orange plastic) from the row > of pins on the power supply. Look along its side. If any of the > plastic over the pins has turned slightly brown, it has developed high > resistance and is heating, and the voltage is spiking and falling. > > If it is *very* brown, or black, it has probably heated things > up badly enough so the solder has melted from around one of the pins on > the underside the power supply's circuit board. (You'll have to pull > the power supply out of the system to verify this, and to work on it.) > > Since it is a 7300, not a 3B1, I suspect that the power for the > hard disk drive is fed through the system board, so it burns the > connector a bit sooner. (Later 3B1 power supplies have a cable soldered > directly to the board to carry power to the hard disk drive, and thus > reduce the current through the rest, though it also typically has a full > 2MB of RAM on the system board, so the current load there increases. > > If the connector is dark brown from overheating, it really > should be replaced. It is possible to pull the back cover off it, then > ease the indivdual wires from the stiff ribbon cable out of the > individual slots, and install them in a replacement connector of the > same type by pressing down on either side of the metal of each pin, with > perhaps the tips of some needle-nose pliers. > > IIRC, the connector has either 18 pins or 38 pins -- I forget > which. > > But, in any case, spray the pins with a good contact cleaner, > and slide the connector on and off the pins several times to clean off > any oxidation. What I use to really like was something called > "Cramolin", but it got discontinued because of something toxic or bad > for the ozone layer, and it was replaced with something called De-Oxit. > > Either of them come in two colors, intended to encourage you to > spray with one, wipe it clean, and then spray again prior to > reassembling. > > Of course, it could be something else, but this is what I would > check first. > > Good Luck, > DoN. > > -- > Remove oil spill source from e-mail > Email: | (KV4PH) Voice (all times): (703) 938-4564 > (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html > --- Black Holes are where God is dividing by zero --- Thank you. I've replaced power supply with a pc atx power supply. Relays are normal now. I'm trying to boot at&t, but i see only running green rectangles. All 4 leds are on. Lithium battery is dead. I will try to replace battery. I think it will solve boot problem.