Allas Posted March 19, 2007 Share Posted March 19, 2007 (edited) I bought a 130XE and dont work properly. I opened and take a look inside. There are some cords (black and white) and maybe is repairing a defective copper rain. I saw there is a empty memory socket, but one of the memory replaced chip is a MB2864A-15 8617 T99 . Is similar to the 1264-15?? When I turn on the 130xe only got a blank screen and a infinite sound. Edited March 19, 2007 by Allas Quote Link to comment Share on other sites More sharing options...
re-atari Posted March 19, 2007 Share Posted March 19, 2007 (edited) I bought a 130XE and dont work properly. I opened and take a look inside. There are some cords (black and white) and maybe is repairing a defective copper rain. I saw there is a empty memory socket, but one of the memory replaced chip is a MB2864A-15 8617 T99 . Is similar to the 1264-15?? When I turn on the 130xe only got a blank screen and a infinite sound. You are in fact missing a DRAM. A 1264-15 should do, IIRC that's a DRAM manufactured by Sharp. If it has the same number of pins it should be all right. Check the line-up of the IC, do not put it in backwards. The other DRAM's might be at fault as well, as MT's (Micron Technology) are prone to fail. re-atari Edited March 19, 2007 by re-atari Quote Link to comment Share on other sites More sharing options...
Allas Posted March 19, 2007 Author Share Posted March 19, 2007 which socket memories are needed to get a blue screen on the Atari? Quote Link to comment Share on other sites More sharing options...
Rybags Posted March 19, 2007 Share Posted March 19, 2007 You might get it working if you swap in one of the other RAM chips. Try the one from the bottom left (assuming your chips are socketed). Quote Link to comment Share on other sites More sharing options...
Allas Posted March 19, 2007 Author Share Posted March 19, 2007 (edited) Thanks, really should be a picture with some indication inside the Atari. Move a memory didnt fix the problem. But I have some questions... - GTIA, POKEY, 6502C, BIOS, ANTIC chips are compatible between 800XL and 130XE models ? - Is the first column of chip memories in the XE the Extended 64K memory? - what are the 2 little chips of 24 and 28 pins? - Is there a schematic in internet about 800Xl and 130XE? - How I could recognize the chips GTIA, POKEY, 6502C, BIOS, ANTIC in the mainboard? Edited March 19, 2007 by Allas Quote Link to comment Share on other sites More sharing options...
Rybags Posted March 19, 2007 Share Posted March 19, 2007 AFAIK - GTIA and POKEY are universally compatible on all machines. ANTIC betwen XL/XE is compatible. OS, not sure - I think the XL used 3x8K ROMs where the XE used only 1 ROM for everything (?) There are schematics available - I don't have the links though. This list should have all the codes for the custom ICs http://www.best-electronics-ca.com/custom-i.htm Quote Link to comment Share on other sites More sharing options...
Tezz Posted March 19, 2007 Share Posted March 19, 2007 Hi, I've been working on repairing and upgrading 3 XE's for the past few weeks, here's the link to the schematics online: http://www.dereatari.republika.pl/schematy.htm If the left side bank is populated U9-U16 the xe should still boot even with faulty ram in the right (extended 64k) bank Regards, Tezz Quote Link to comment Share on other sites More sharing options...
Rybags Posted March 19, 2007 Share Posted March 19, 2007 Maybe try it with all the chips in the RH bank taken out. Then, if it works OK, try swapping in some of the ones you took out - determine if you have any faulty chips. Quote Link to comment Share on other sites More sharing options...
re-atari Posted March 19, 2007 Share Posted March 19, 2007 Thanks, really should be a picture with some indication inside the Atari. Move a memory didnt fix the problem. But I have some questions... - GTIA, POKEY, 6502C, BIOS, ANTIC chips are compatible between 800XL and 130XE models ? - Is the first column of chip memories in the XE the Extended 64K memory? - what are the 2 little chips of 24 and 28 pins? - Is there a schematic in internet about 800Xl and 130XE? - How I could recognize the chips GTIA, POKEY, 6502C, BIOS, ANTIC in the mainboard? In addition to the info Rybags and Tezz have already posted above, the 24 and 28 pin IC's are resp. the Basic (8 Kbyte) and OS (16 Kbyte) rom. The OS is directly pin-compatible with a 16Kbyte eprom (27128), but Basic is a masked rom which is only partly pin-compatible with a corresponding 8 Kbyte eprom (2764). Your XE has Basic rev. C, which is the most bugfree of the various Basic's Atari introduced in its 8-bits. Judging from your photo I see someone before you already took the trouble of socketing the IC's. This will prove to be a real bonus if your DRAM's turn out to be OK, and you have to investigate other IC's for possible defects. re-atari Quote Link to comment Share on other sites More sharing options...
Rybags Posted March 19, 2007 Share Posted March 19, 2007 That 3rd chip down in the second row seems to be a MB8264A-15. According to the datasheet from http://www.datasheetcatalog.com/datasheets...2/MB8264A.shtml (click download to get popup PDF datasheet) it has a cycle time minimum of 260 ns. From info I've read in the past, the Atari supposedly requires 250 ns maximum access time for RAM chips - I'm not sure if that particular chip would be causing problems though. In any case, that vacant socket renders that bank of RAM unusable anyway. Quote Link to comment Share on other sites More sharing options...
Allas Posted March 20, 2007 Author Share Posted March 20, 2007 (edited) Thanks for the help to everyone, I exchange chips from two column, remove the special memory chip, and remains in the same way. I think there is a little or incomplete modification in the mainboard. I need some new chips ANTIC, GTIA, 6502, POKEY and even the OS ROM and I saw what happen. At least, Ive learn a little of "Repairing a Atari 8-bit for Dummies" Edited March 20, 2007 by Allas Quote Link to comment Share on other sites More sharing options...
re-atari Posted March 20, 2007 Share Posted March 20, 2007 Thanks for the help to everyone, I exchange chips from two column, remove the special memory chip, and remains in the same way. I think there is a little or incomplete modification in the mainboard. I need some new chips ANTIC, GTIA, 6502, POKEY and even the OS ROM and I saw what happen. At least, Ive learn a little of "Repairing a Atari 8-bit for Dummies" You might want to get hold of a 600XL or 800XL, as these have all IC's socketed. Since your XE already has sockets (which is uncommon with XE's) you might find the culprit by simply swapping IC's one at a time into the working computer. It's probably not a bad idea to check if the XE's power supply outputs the correct voltage, beforehand. Atari used a number of different PSU's and some types (especially the 'brick' type enclosure without the ventilation holes) are known to fail, most likely because of dried out electrolytic capacitors. re-atari Quote Link to comment Share on other sites More sharing options...
+orpheuswaking Posted March 20, 2007 Share Posted March 20, 2007 (edited) You know I've seen this 800xl is socketed thing several times here, and I have to tell you I have 2 NTSC and 4 PAL 800XL machines and not a single one is Socketed Edited March 20, 2007 by orpheuswaking Quote Link to comment Share on other sites More sharing options...
+bf2k+ Posted March 21, 2007 Share Posted March 21, 2007 You know I've seen this 800xl is socketed thing several times here, and I have to tell you I have 2 NTSC and 4 PAL 800XL machines and not a single one is Socketed Most of my 800XL's (all NTSC) are NOT socketed. Quote Link to comment Share on other sites More sharing options...
+warerat Posted March 21, 2007 Share Posted March 21, 2007 There are some cords (black and white) and maybe is repairing a defective copper rain. Those two wires are normal on 130XE's. All the ones I've seen or own have them. Quote Link to comment Share on other sites More sharing options...
dinosaur Posted March 21, 2007 Share Posted March 21, 2007 You know I've seen this 800xl is socketed thing several times here, and I have to tell you I have 2 NTSC and 4 PAL 800XL machines and not a single one is Socketed Most of my 800XL's (all NTSC) are NOT socketed. From my limited experience,most 800XLs manufactured in Hong Kong were socketed and most manufactured in Taiwan were not. Quote Link to comment Share on other sites More sharing options...
Allas Posted April 12, 2007 Author Share Posted April 12, 2007 (edited) Well , I have another 130xe in good condition and I can compare both computers. In front all pieces are equal, but in the back i saw a suspect cord in the first two memory sockets. I think its a type of modification with the strange memory chip in front, and in other way I received the 130xe with the first memory chip empty from the extended column, as it could see in the first picture. What could I do, cut the cord? anyone knows what means this mod? Edited April 12, 2007 by Allas Quote Link to comment Share on other sites More sharing options...
Rybags Posted April 12, 2007 Share Posted April 12, 2007 All it seems to be doing is connecting 2 same pins on 2 memory chips. Possibly due to a bad trace. So long as the machine works, just leave it there. Quote Link to comment Share on other sites More sharing options...
re-atari Posted April 12, 2007 Share Posted April 12, 2007 (edited) All it seems to be doing is connecting 2 same pins on 2 memory chips. Possibly due to a bad trace. So long as the machine works, just leave it there. I agree. Judging by you photo, someone before you already went through the trouble of desoldering and socketing all major IC's. My guess is he ruined a trace in the process (pin 5, which is adressline A5), and fixed it later with the help of this wire. Leave it in place, the error is somewhere else. re-atari Edited April 12, 2007 by re-atari Quote Link to comment Share on other sites More sharing options...
Allas Posted April 12, 2007 Author Share Posted April 12, 2007 I replaced the 6502, POKEY, GTIA, ANTIC and OS chips. Before that I got only a Black screen with noise, now I got a memory test menu, but it filled with garbage that continuously move vertically. Any function is available. Well, still remains the Freddie and PIA chip. But, I think how can I test the good condition of minor pieces, the resistors, capacitors? I'm not electrician man, I suspect i need a electronic tester tool. Quote Link to comment Share on other sites More sharing options...
re-atari Posted April 12, 2007 Share Posted April 12, 2007 (edited) I replaced the 6502, POKEY, GTIA, ANTIC and OS chips. Before that I got only a Black screen with noise, now I got a memory test menu, but it filled with garbage that continuously move vertically. Any function is available. Well, still remains the Freddie and PIA chip. But, I think how can I test the good condition of minor pieces, the resistors, capacitors? I'm not electrician man, I suspect i need a electronic tester tool. A digital multimeter is a tool any serious hardware tinkerer should have in his inventory. It doesn't have to be a Fluke or Metex for starters. Far-east models (made in China) can be had very cheaply these days (sometimes 10-15 US$ for basic ones), so do yourself a favor and just buy one. I suggest you shell out a little bit more cash and go for a model with a diode test (beep mode) and a capacitor measurement. You will not regret the purchase. re-atari Edited April 12, 2007 by re-atari Quote Link to comment Share on other sites More sharing options...
Allas Posted April 12, 2007 Author Share Posted April 12, 2007 Its possible to test the good condition of capacitors and resistances in the mainboard without desoldering them? Quote Link to comment Share on other sites More sharing options...
re-atari Posted April 12, 2007 Share Posted April 12, 2007 (edited) Its possible to test the good condition of capacitors and resistances in the mainboard without desoldering them? Not really, unless you have the schematic at hand and can interpret the readings you get. There really is no alternative but to desolder and test measure suspect components. And even then you can see some amazing and sometimes even puzzling results. In an earlier thread in this forum I already wrote about the trials and tribulations I had to go through when repairing a defective 800XL (erratic rom/ram error). I got rid of this error situation by replacing a few resistors and capacitors. Strange thing was, these components all measured OK when desoldered. Another example: the adapter for my wireless router failed about a month ago. It should deliver 5V, which it did without load. As soon as I connected the router again, voltage dropped to about 3V. It turned out the adapter contained a small switching powersupply. A big capacitor (1000 uF) in the output circuitry situated directly next to a cooling fin drew my attention, as it was swollen (yes, literally). Looks like it had developed too much ESR (Ohms resistance due to drying out). After desoldering it still showed a significant capacitance when measured, but apparently not enough to maintain the 5V under load. Since I don't have an ESR-meter in my equipment (you can't have every tool), I replaced it with a brandnew capacitor all the same. With this the adapter was as good as new again. Well, almost, as I had to crack open the casing which was glued shut, luckily it gave in along the glued casing edges without any damage. A few drops of superglue in the corners (in case I have to open it again in the future), and you couldn't even see it had ever been opened. But main thing is, my router fired up without a hitch, and has not collapsed since. The point of my story being: get your measuring devices, and learn how to use them. Only time and experience, which comes by trial and error, will give you an additional intuitive feeling as to which component(s) need to be replaced when repairing electronic stuff. Of course, it can't hurt if you can fall back on the experience of fellow members in this and other forums A kind question will 9 times out of 10 be rewarded by constructive answers, but sometimes nobody can help you, and you're left to your own devices. re-atari Edited April 12, 2007 by re-atari Quote Link to comment Share on other sites More sharing options...
Urchlay Posted April 12, 2007 Share Posted April 12, 2007 ... Looks like it had developed too much ESR ... ...I hate it when my router develops too much Eric S. Raymond (apologies, if that doesn't make anyone smile...) Quote Link to comment Share on other sites More sharing options...
re-atari Posted April 12, 2007 Share Posted April 12, 2007 ... Looks like it had developed too much ESR ... ...I hate it when my router develops too much Eric S. Raymond (apologies, if that doesn't make anyone smile...) LOL. Now that's a controversial fellow. Open source software promotor and fire arms advocate in one... I wouldn't mind open source in my router, but a fire arm? Never... To stay on topic (somewhat), here are links to a few homebuilt ESR-meters. I'm tempted to build one of these shortly, they're fairly simple to construct, but haven't decided yet which one. Take a look at http://www.ludens.cl/Electron/esr/esr.html and http://www.qsl.net/iz7ath/web/02_brew/15_l...6_esr/index.htm re-atari Quote Link to comment Share on other sites More sharing options...
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