NightSprinter #1 Posted August 30, 2006 (edited) Hi there, I somehow purchased what seems to be a non-functional 520STf from eBay a couple months ago. The system powers up, but there's no disk access (apparently someone tried to put a PC floppy in the machine?), and there's this horridly high-pitched squeal from the computer overall. Opening the case reveals no RF shielding whatsoever (as it doesn't have the TV modulator or the holes cut out for it, apparently). Is there any way in which I can bring the computer back to functional status once the RGB cable for my 1084S-D that I ordered for the Atari computer arrives? Edited January 9, 2007 by NightSprinter Quote Share this post Link to post Share on other sites
tjlazer #2 Posted August 30, 2006 Sure get a proper drive for it, all should be good. If you want you can get a PC drive and hack the case. Get a Chinon FZ 357 or Epson SMD 300/340. Quote Share this post Link to post Share on other sites
NightSprinter #3 Posted September 23, 2006 Here's the clincher. I just got my monitor cable for my 1084S-D2 monitor, and when I powered the system on (yes, switched the RGB system to Digital) there was no GEM desktop. Did something happen that I wasn't aware of? Quote Share this post Link to post Share on other sites
jens #4 Posted September 24, 2006 Well - what was there? Quote Share this post Link to post Share on other sites
tjlazer #5 Posted September 24, 2006 (edited) You mean you power it up and you get a green screen with no icons? Or white screen? If black screen, computer is DEAD, white means semi functional (try 4" universal drop) and green with no icons means dead or no drive connected. Edited September 24, 2006 by tjlazer Quote Share this post Link to post Share on other sites
NightSprinter #6 Posted September 24, 2006 Well, I guess the best quote would be the infamous one from Star Trek: "It's dead, Jim.." So, how do I fix it since it's a black screen, and I also get tis irritatingly high-pitched squeal? Quote Share this post Link to post Share on other sites
+remowilliams #7 Posted September 24, 2006 (edited) Here's the clincher. I just got my monitor cable for my 1084S-D2 monitor, and when I powered the system on (yes, switched the RGB system to Digital) there was no GEM desktop. Did something happen that I wasn't aware of? The ST does not use digital RGB, it's analog. Digital RGB is for the C128. As far as the squeal (if it is coming from the computer), unplug the power from the floppy drive and try. If its still squealing then I'd say its your power supply making that noise. Make sure that noise isn't coming from your monitor being driven incorrectly! Edited September 24, 2006 by remowilliams Quote Share this post Link to post Share on other sites
NightSprinter #8 Posted September 25, 2006 Ok, when I set it up to analog RGB I just saw nothing but green and purple bars scrolling. Are you sure it's analog RGB for the ST and up? Quote Share this post Link to post Share on other sites
+remowilliams #9 Posted September 25, 2006 Ok, when I set it up to analog RGB I just saw nothing but green and purple bars scrolling. Are you sure it's analog RGB for the ST and up? Positive. The ST/Amigas are analog RGB. TTL (digital) RGB is used by the C128 and EGA type PC monitors. I have several STs and several 1084 monitors - one is a 1084S-D1 I believe analog is the button pushed in, and TTL is out. Quote Share this post Link to post Share on other sites
NightSprinter #10 Posted September 25, 2006 Mine is the 1084S-D2 then (left/right switch for Analog/Digital TTL). But what about the green/purple scrolling lines? I know that means one or more chips have gone bad, but don't know what chips. Quote Share this post Link to post Share on other sites
jens #11 Posted September 25, 2006 Press all chips back into their sockets. Then switch it on and tell us about it. Quote Share this post Link to post Share on other sites
NightSprinter #12 Posted September 25, 2006 Just did so, still the rolling green and purple bars. I did find out the power supply seems to be bad, so I'll have to order a new one from Best Electronics next paycheck. That, plus I need to get some screws to keep the top half of the case still, despite I don't have the top half of my computer's RF shield. Quote Share this post Link to post Share on other sites
jens #13 Posted September 25, 2006 The rf shielding is not too important. And four screws are enough for the top. Quote Share this post Link to post Share on other sites
NightSprinter #14 Posted January 9, 2007 Well, today I'm sending Mitch the monitor cable I have for it for inspection.. so the only real issue I have left is a lack of internal floppy drive. Ideas on where to get one? Quote Share this post Link to post Share on other sites
carmel_andrews #15 Posted January 9, 2007 nightsprinter, i think you mean 520 stfm...only 1040's came as stf's Quote Share this post Link to post Share on other sites
ppera #16 Posted January 9, 2007 Just did so, still the rolling green and purple bars. I did find out the power supply seems to be bad, so I'll have to order a new one from Best Electronics next paycheck. That, plus I need to get some screws to keep the top half of the case still, despite I don't have the top half of my computer's RF shield. Very likely your ST has some more serious failure(s). With approach like this you will spend lot of money to fix it. Ordering power supply, cable, floppy for it will cost more than buying functional machine. There is even possibility that machine is in very bad condition, with lot of bad chips - if someone opened it he could replace good chips with bad ones, and selling so... Not to mention that bad power supply can kill many chips in moment. Littlest problem is PC floppy drive in - it works with ST, and only problem may be bad floppy change detection, but it is solveable: http://www.ppest.org/atari/flomodam.html If you are lucky, there is possibility that there is just no sync. Maybe fixing cable will solve it.... Quote Share this post Link to post Share on other sites
NightSprinter #17 Posted January 9, 2007 No, there's no RF Modulator in the 520. I've checked many times. Plus on the screen problem, I'm quite certain now that it's a problem with the sync lines for the monitor cable. The picture was a little more viewable if only plugged in partially (albeit a lot of buzzing from the speakers on my 1084S and the colors aren't exact). Quote Share this post Link to post Share on other sites
tjlazer #18 Posted January 10, 2007 So the case says 520STf on it? Are there holes in the back for RF mod parts? Weird never heard of a 520STf. Maybe someone hacked it. Quote Share this post Link to post Share on other sites
NightSprinter #19 Posted January 10, 2007 Well I'll be damned. The top of the case itself says 520STfm, but the board (and also the bottom half of the case) lacks anything for the RF modulator. Quote Share this post Link to post Share on other sites
mons2b #20 Posted January 10, 2007 Well I'll be damned. The top of the case itself says 520STfm, but the board (and also the bottom half of the case) lacks anything for the RF modulator. Would it not be cheaper to get another STFM? Ive had to do a few parts swaps to revive some machines at the expense of others. JW Quote Share this post Link to post Share on other sites
NightSprinter #21 Posted January 10, 2007 Not in this case. The system just lacks its own RGB cable, and an internal floppy drive. Quote Share this post Link to post Share on other sites
tjlazer #22 Posted January 10, 2007 Does the MB have 1MB RAM on it? maybe it is a 1040ST MB. I have a 520STfm with 1MB here, but has a 360k drive in it! Doh! Quote Share this post Link to post Share on other sites
NightSprinter #23 Posted January 10, 2007 (edited) Does the MB have 1MB RAM on it? maybe it is a 1040ST MB. I have a 520STfm with 1MB here, but has a 360k drive in it! Doh! Well well.. it is INDEED a 1040STf board. I just did a Google search for the part number: C070523-001 REV. A, what few results that returned all point to it being the board to the 1040STf. Must have been upgraded or replaced at one point? Because I can see the cutouts in the plate shielding for the RF MOdulator, but no cutouts on the plastic itself. Also forgot to mention, only the top half of the case is from a 520STfm, the bottom half says "1040STFM". Edited January 10, 2007 by NightSprinter Quote Share this post Link to post Share on other sites
tjlazer #24 Posted January 10, 2007 Thats what I figured, a 1040 MB and bottom casing, and a 520STfm top case. Quote Share this post Link to post Share on other sites
NightSprinter #25 Posted January 11, 2007 Regarding who gave the suggestion for the floppy drive mod.. I suck at soldering (quite badly at that). Any other suggestions for a replacement? Quote Share this post Link to post Share on other sites
Like us on Facebook
Follow us on Twitter
AtariAge on Instagram
Watch us on YouTube
Chat on Discord