garlow@lpl.arizona.edu (Kevin Garlow x2272) (10/29/90)
Hi! I had a crisis with my computer which I'm going to describe in the hopes that one or more of you can help me out... I was using AtariWriter on my Atari 800. I tried to print something out and nothing happened, which was when I noticed that the power LED on the 850 printer interface wasn't lit. I checked that it was turned on, tested the power cord, and finally decided that either the 850 or its power transformer was dead. I noticed that the transformer which powers the 800 was identical to that of the 850 (same product number, etc.), so I thought I could verify which was bad (the 850 or its transformer) by switching the transformers between the 800 and the 850. It seemed like a harmless idea at the time. Unfortunately, not only didn't either one work, but when I switched my computer back to its own tranformer, it no longer worked (no power indication-- nothing). Yikes! What could have happened? Here are three hypotheses: 1) Both transformers chose to die within several minutes of each other, but there was no cause and effect involved. 2) The 850's transformer "went bad" and damaged not only the 850, but the 800 as well. 3) The 850 "went bad" and damaged not only the 850's transformer, but the 800's as well. Which of these hypotheses sounds most plausible from a technical standpoint? I'd appreciate any suggestions on how to determine what happened, as well as where I might be able to mail order a new power supply (or whatever would be required to fix the 800 computer and 850 interface). There are no dealers in town. Post any replies, OR email to: garlow@hindmost.lpl.arizona.edu and I will follow up with a summary. Thanks! Kevin Garlow
rfc@briar.Philips.Com (Robert Casey) (10/29/90)
In article <346@organpipe.UUCP> garlow@lpl.arizona.edu (Kevin Garlow x2272) writes: > 3) The 850 "went bad" and damaged not only the 850's > transformer, but the 800's as well. There is a fuse inside the transformer's plastic housing. It is possible that a defect in the 850 blew fuses in both of your transformers. It is possible to repair the transformers by gently squeezing the plastic housing at the joint in a vise. This should crack the glued joint enough so you can pry it open. then look at the fuse and replace it if bad. Then the next question is what may be wrong with the 850. Open the plastic housing and inspect the power connector for a short. Beyond this, you'll need some electronics smarts to find the problem. Probably a defect in its ac to dc conversion circuits.
mwjester@wsuiar.uucp (loki) (10/30/90)
In article <346@organpipe.UUCP>, garlow@lpl.arizona.edu (Kevin Garlow x2272) writes: [...Synopsis: notices that his 850 has no power, tries plugging in the transormer from his 800, now neither one works. Hypotheses:...] > > 1) Both transformers chose to die within several minutes > of each other, but there was no cause and effect > involved. > > 2) The 850's transformer "went bad" and damaged not only > the 850, but the 800 as well. > > 3) The 850 "went bad" and damaged not only the 850's > transformer, but the 800's as well. > > Which of these hypotheses sounds most plausible from a technical > standpoint? My vote is on number 3. If pressed, I would look for a dead short in the 850 somewhere that killed both power supplies. (I'm guessing that Atari didn't protect either transformer via fuse - after all, sealed units never need service, right?) Maybe there's a fuse blown in the 850, but this is unlikely - if it doesn't protect the transformer, it's not doing much. As far as replacement goodies, I'm not sure - BRE's catalog had some 8-bit hardware stuff last I saw, but I haven't looked at a recent one. Are there no 8-bit magazines left for suppliers to advertise in? Good luck! Max J.