rick@jhunix.HCF.JHU.EDU (Eric Ruck) (01/10/90)
OK, I've got a dead Mega 2 ST. Probably the power supply. For about 20 seconds it sounded like there was a piece of paper caught in the fan, then the thing completely blacked out, no power light or anything. Thus far, my alternatives to getting it repaired seem to be either having one local repair center cannabilize a 1040 power supply at a cost (parts and labor) of around $200, or having the thing sent back for $60 and six or so weeks, none of which seem attractive to me. Is there anyone who has had this problem, and can suggest a way a couple of undergraduate EE majors can fix it? Is there any reason that the power supply in a computer that is of course out of warrantee but less than six months old and plugged into a fairly decent power line filter and surge protector should die? My old 520's have never needed repair, but if that's the way Atari builds their new computers, maybe the popular opinion of computers isn't so off-base (yes, this is somewhat of a flame. I've got too much invested in the damn thing to have to deal with hardware beneath even Apple's standards). Eric
econadm5@watserv1.waterloo.edu (BENTLEY BH - ECONOMICS) (01/10/90)
In article <3906@jhunix.HCF.JHU.EDU> rick@jhunix.UUCP (Eric Ruck) writes: > >OK, I've got a dead Mega 2 ST. Probably the power supply. For about 20 >seconds it sounded like there was a piece of paper caught in the fan, then >the thing completely blacked out, no power light or anything. > >Thus far, my alternatives to getting it repaired seem to be either having one >local repair center cannabilize a 1040 power supply at a cost (parts and >labor) of around $200, or having the thing sent back for $60 and six or so >weeks, none of which seem attractive to me. > >Is there anyone who has had this problem, and can suggest a way a couple of >undergraduate EE majors can fix it? Well I have fixed several Atari St Machines and upgraded many of them. The cause of the power failure could be anything from grounding out the disk drive connector to the Dma port etc over a period of time. Most likely the cause was a cold solder joint that over time heated up and then had no connection. These cold solder joints can be located at various spots but from experience near C10 C11 or where any of the wires that enter or exit the power supply board. I have had to replace a leaky capacitor at c13 and a fuse time to time(normally due to improper disconnection of the power supply). Regardless before sending it off look high an low for a cold solder joint on the power supply board. If you require any more assistance send me mail and Ill see how I can help. Dave Tomesch , Super BBS (519) 749-1206 250Megs. Brain Bentley KWEST Editor " Never say Never"
clf3678@ultb.isc.rit.edu (C.L. Freemesser) (01/11/90)
In article <3906@jhunix.HCF.JHU.EDU> rick@jhunix.UUCP (Eric Ruck) writes: > >OK, I've got a dead Mega 2 ST. Probably the power supply. For about 20 >seconds it sounded like there was a piece of paper caught in the fan, then >the thing completely blacked out, no power light or anything. > >Thus far, my alternatives to getting it repaired seem to be either having one >local repair center cannabilize a 1040 power supply at a cost (parts and >labor) of around $200, or having the thing sent back for $60 and six or so >weeks, none of which seem attractive to me. > >Is there anyone who has had this problem, and can suggest a way a couple of >undergraduate EE majors can fix it? > It's always been my OPINION that the internal power supplies found in ST computers have been wimpy. Yours may have just gotten overloaded or something. Who knows. What we DO know is that it is dead. Is it worth putting another one in? I'd say no. Try something else. I have my 520, 2 drives, and XE hooked up to a single power supply. It's a nifty no-RF unit I picked up from Computer Software Services (the 8-bit folks who manufacture the SUPER ARCHIVER and BLACK BOX). It puts out 5V @12A, 12V @1.5A, and -12V@ .5A. If you'd be interested in it, give em a call: 716-586-5545. It's $80 or so, but it's worth it. You won't have to worry about wimpy power supplies. I've never seen how Atari has the internal power supply hooked up. Whether it is done with wires, or terminals soldered right to the motherboard, I don't know. The external supply is certainly less than $200, and you won't have to wait 6 weeks for it. You might also try Best Electronics. They can probably set you up with a new Mega supply. The part number is : CB101507. No price listed. As for replacing it yourself, it should be quite easy. Chris Freemesser, Rochester Institute of Technology :BITNET:%clf3678@RITVAX ||| ____________ :GEnie: C.FREEMESSER ||| /___ / (and 8-bit too!) :USENET: clf3678@rit.isc / | \ ______/ / : .edu Call the A.C.O.R.N BBS (716)436-3078, 300/1200 baud :<-or my BBS