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Found 39 results

  1. Hello everyone, I'm new to the Classic Mac refurbishment game. I'm in need of schematics for the analog sweep board p/n 630-0525. It's the US 110V version. Any help would be much appreciated! Rick
  2. Hello everyone! I don't want to quit from this project yet, I recapped each and every single capacitor on the logic board and the analog board. Replaced the two diodes (DP3, DP4) and the optocoupler as some suggested. Reflowed most of the solder joints on the back of the board and searched for broken or cold joints. No luck. The only way I'm able to increase the voltage to the minimum required to boot is using a hair dryer (shown on the video below). I tried to pinpoint the exactly location where the hot air flow is directed and it seems to be the top part where the MOSFET and some caps are located. Does anyone know what could be the issue? Please I don't know what else to try. Many thanks!
  3. Hi! New here Was going to post this here first, but as my activation email didn't get thrue until today, I posted this already in Reddit /r/vintageMac. I came across a local ad for a Mac 512K keyboard and mouse. Reading the ad, I noticed that it actually noted "a non-working Mac 512K can also be included". This was interesting as I rarely see Macs of this vintage locally, and this was only a short distance away from me. From the photos I could see that the machine was a 120V which was interesting (living in a 220V country). Ok, I went to bought the set for less than 100$. What I have observed so far: Serial number dates the unit to a late 1985 A battery was still inside, but it had leaked only a very little and after cleaning and scraping the battery contacts they look Ok. There was no damage to the PCB where the holder sits. The floppy drive is a Sony MP-F51W, meaning that it has been upgraded (800k) ROMs are 23512-1010 and 23512-1007 (ie. "old ROMs" if I am not mistaken?) The analog board is marked 630-0102-J (ie. US, 110V non-switchable?) The digital board looks pristine and all the solder joints look original as well. Keyboard (M0110, 1985 per serial) and mouse (M0100, 1985) look intact and are reasonably clean. Keyboard cable is missing (seller said he might still have it, I might get it later). Externally the computer is in average condition, only major issue being a burnt spot in the plastic at the top left (covering part of the vent and also a bit of the front panel's top). The two short T15 screws were missing, perhaps a repair-attempt was made but they never get the case open due to the two recessed screws in the handle-space I have not tried to power up the unit yet. There was no backstory of how it failed, but being a 120V set in a 220V country, it's most likely that it was plugged in without step-down transfomer and was struck with overvoltage mains. Looking at the analog board, I see very little obvious damage. The fuse and resistor R51 next to the mains input have obviously burnt. On the bottom of the board resistors R46, R47 and R49 have slight discoloration and all three had their values gone very high. I have also done some measurements according to the books "Macintosh_Repair_&_Upgrade_Secrets_1990" and "The_Dead_Mac_Scrolls_1992" (there are plenty of in-circuit resistance measurements to go by). At the moment I am thinking about replacing the obviously burnt (/gone-high value) resistors, keep measuring around to find anything else obvious, and then power up (with a proper step-down converter). Adding to a larger component order (need to do this during the weekend), I'll also buy some spares of the nearby components (next to the burnt resistors in the schematics) like Q11, Q9 and perhaps the opto-coupler U3 too? Also some electrolytics, but I am not bothing a full re-cap yet. At first I'd like to see if replacing the obvious faults would give me any signs of life. Now my main question is; has anyone experienced a similar 120/220V over-voltage repair? How much was damaged etc. Any other pointers on what to keep an eye on?
  4. I've been having A/V problems for some time now, I asked people on r/VintageApple and they said I should recap logic board. I already replaced all cylindrical capacitors on the analog board and a professional replaced the capacitors on the logic board, but alas, there wasn't any change, I still get this checkerboard on startup and there's no sound at all (except some occasional faint screeches). I am getting really desperate for solutions because this is a very specific problem that has not been (probably) documented yet. I really want to make my Mac Plus work again, but anything I've tried did not help at all (I guess I don't have to worry about caps anymore...). I have little experience with electrical circuits but from what I understand, picture is relayed through RAM, so maybe the RAM is broken? Although it shows 2,560K installed which is in fact the amount of RAM installed... Maybe there's a bad contact on J4, I really don't know. So, people of M68kmla please help me! P.s. along the things I already did is checking the voltage, it was a bit off and I did set it to 5V, but alas, no difference.
  5. It’s been long in coming but I finally kicked it out today. Yes, even your working order Mac 128K through the Plus can use a recap. A video INDEX is in the text description on YouTube to help you easily refer to different sections of this 1 hour video. Even if you aren't interested in a recap, check out the bad Flyback segment where it lights up in the dark!
  6. Hello from Lisbon Although this is my first post, I’ve been visiting this forum looking for clues on what might be wrong with a 1991 Macintosh Classic. I’ll try to clearly describe what happened so that owners with similar symptoms will be able to repair their Classics. I have no experience in electronics so please be patient and use a descriptive language for troubleshooting. I bought it knowing it didn’t work. The early symptoms were: No screen No disc activity No bong or any noise whatsoever Power cable was working I proceeded to remove the rear cover and noticed that, although it had been repaired in the past – some of the Analog Board capacitors were replaced – it was in general mint condition. The keyboard keys still had the mould texture so I guess it just stood in a corner, not being used. The insulator vinyl was missing as were all four plastic clips. It included the 40MB SCSI HDD (it spins and sounds “normal” when connected to an ATX power source) and a full 3MB memory expansion board. The Logic Board capacitors were still the original ones. I did noticed some mild electrolyte spilling – which I carefully washed away – but decided not to replaced them while I was troubleshooting the booting problem. With the rear cover off, connected to the power outlet and switched on, I could feel some warmth with my hand over some points in the back of the analog board, mainly near the flyback transformer and the QP2. While tinkering with a digital multimeter, near the QP2 transistor, I caused the fuse to blow. After that accident any fuse would blow once I attempted to turn the Classic on. Following this thread: https://68kmla.org/forums/index.php?/topic/22946-macintosh-classic-keeps-blowing-fuses/ I proceeded to replace: QP2 - transistor - original: CET 48C0 CEF02N6 - replaced with: IRFBC40 CP23 - blue ceramic capacitor - original: HR R 27 IJ 2KV - replaced with: (I will see it when I get home) RP40 - resistor - original: Red Red Brown Gold (220 Ohms 5%) - replaced with: (I will see it when I get home) DP5 - rectifier - original: BYT03 300 C039 - replaced with: (I will see it when I get home) I also replaced the usual bunch of capacitors: (The only reference I had was based on the previous values installed, please inform if you find any abnormal values) CP2 - 470uF - 35v - 10mm - 105° CP6 - 1000uF - 25v - 10mm - 105° CP7 - 1000uF - 25v - 10mm - 105° CP8 - 2200uF - 16v - 13mm - 85° CP9 - 470uF - 25v - 10mm - 85° CP10 - 470uF - 25v - 10mm - 85° CP12 - 1000uF - 25v - 10mm - 105° CP36 - 1000uF - 16v - 10mm - 105° As a result of these replacements I’m back to square one. The fuse no longer blows but there’s no action whatsoever. Yesterday I looked at Larry Pina’s 1993 edition of “Repair and Upgrade Secrets”. In the section dedicated to the Classic’s Analog Board troubleshooting (chapter 9, page 174) he mentioned the RP2 surgistor (?) could be at fault. 12 Ohm=good, 0.0L mOhm=bad. But I don’t know how to use the Digital Multimeter to test this. I resoldered it, but to no avail Additional Data Analog Board: 820-0395-C, 240V, wired JP1 jumper. I attached a picture of the back of the analog board after having removed the bad capacitors and giving it a thorough clean. What can I do now? Do you have any idea/procedure I could try? It’s so sad to see this beauty of a computer standing there, dead. I would love to hear from this community. Thanks
  7. Below are 2 photos of AC line filter "LF2" from two different Macintosh 128k~Plus Analog Boards. The newest board is stamped 4192 (1986 PCB), which I assume means 42nd week of 1992, and uses the LF2 without the green Earth wire. The other PCB is a 1983-84 version stamped 0792, which I assume means 7th week of 1992, and you can see it has the green earth wire wound inside LF2. Indeed, most every Analog Board I've seen has the Earth wire wound in LF2. Why do you think the green Earth ground wire was not wound into LF2 on the 4192 board? By the way, the 3-pin power connector mounts those 3 pins to the PCB, but the Earth pin has no PCB trace. Regardless of which board we look at, the Earth ground coming from the power cord screws down to the metal chassis, so the chassis is Earth grounded. It's simply a matter of why that green Earth wire does or does not go through LF2 that I am curious about. Search this PDF for "LF2" as a keyword to see the schematic which mentions that it does indeed go through LF2. Hmmm...
  8. I tend to swap out the electrolytics in a recap and leave the film or metalized paper caps alone if they are good. Some among us have experienced blown filter caps near the power input on the original Macintosh analog boards, specifically these Rifa caps: C33: 4700pf 250VAC Minibox (sometimes found to be 2200pf?) C37: 4700pf 250VAC Minibox (sometimes found to be 2200pf?) C38: 0.1uF 250V Minibox The stock Rifa caps all appear to be metalized paper capacitors. A directed replacement for C33 and C37 would be the KEMET PME271YA4470MR30, also metalized paper. But would a Polypropylene version safety capacitor like the WIMA MKY22W14703F00KSSD be a better choice? There is also the KEMET F462AG472J1L2A polypropylene cap, but it is not classified as safety and therefore I do not know if it's failure mode would be open circuit when it blows. Similar thinking should apply to replacements for C38. Please let me know your thoughts. Thank you.
  9. mac1nt0s

    Analog Board Recaping Advice

    Hello! I've decided to recap the analog boards in my Macintosh SE and SE/30 and now I need to buy the caps and I'm wondering a few things: - which company should I buy the caps from (there's quite a lot of different companies and I don't really know which ones to buy)? - should the max operating temperature be 105 C or is 85 C enough, considering that the SE and the SE/30 have a fan? - is it okay to buy the caps from AliExperss (I know that Mouser is generally the best for capacitor purchases, but the shipping is quite expensive, because I'm located in a smaller country and I really don't want to pay that much for shipping)? Thank you for taking your time and helping me out!
  10. It took me a while but I finally got my SE & SE/30 Analog Board recapping video published to YouTube today. Safari users, note that you'll need Chrome or FireFox to watch it in 4K. Don't forget to watch it on YouTube so you can check out the links I put in the text description (click SHOW MORE to see all of it), including the Mouser Cart that includes all the capacitors you will need. Enjoy.
  11. Hi all, I was recapping an SE's Rev A analog board and found a diode soldered between CR4 and a resistor I can't see the designation of, and a capacitor between that diode and R26. Is that a modification to basically mod it into a Rev B? Can anyone shed some light on to what this does exactly? Thanks, Mingo.
  12. I have an analog board of a Classic II that shows a single horizontal line on the screen. I replaced the TEA2037A but that did not change anything. With another analog board, the Mac works. What else can influence the vertical deflection?
  13. dochilli

    Classic analog board 0 Volt

    I have two classic analog boards that show 0 volt at the floppy port. I measured the volts at cp22 and one had 45 Volts, the other had 0 volt. At a functioning board I measured 90 volts, but I read in another thread that there should be 300 volts. Anay ideas, where I can find the defect part?
  14. Hi everyone So I have something that wouldn't really be considered unusual a very sick Macintosh Plus I have yet to see it boot or do anything else than try and kill it's self. I bought this Macintosh Plus off a Friend who had more money than sense and he bought it from Canada and had shipped here to Ireland, sadly he thought it would be a simple plug and play and he never heard of a step down converter. when he plugged straight in the Irish 250V socked it blow the crap out of it and he said it just popped. So 2 months later he offered it to me because he bought a UK one instead and I got it for a tidy €40 which is cheap on this side of the pond even for a broken one. On opening the machine I noticed 2 things the Fuse on F1 was blown looked burn't out and the thermistor on R39 was broken in half. so I replaced both of those think this may resolve the issue but both the Fuse and the thermistor blow again with spark's coming form the new thermistor and I new I did buy the right one but when I took a second look at the board both the Rectifier and Diode on CR20 and CR21 had heat damage on there legs, I have also replaced these and this fixed one issue the Thermistor no longer sparks but the fuse is still blowing when I plug it in. Yes I am using a step-down converter which I have tested that output's 117V to be exact so it should be safe. There is one more thing I can think of which is the Fuse trace lead's directly to 3 spick suppressing capacitor's the first one is a large one which I have just removed to test with a Multimeter (which I know isn't exactly accurate but my ESR meter is broken and waiting for a new one in the mail) and it has showing no signs of life on capacitance on the multimeter so I'm guessing this could be dead and causing the fuse to blow I'm not use it's only 0,1uf 250V this located on C38 and the other 2 are C33 and C37 are these known to case a fuse to blow ?. I would be very grateful for some in put on this analog board I have wanted a Macintosh Plus since my Grandad would let me play on his just a bit of nostalgia, also this Analog is starting to get expensive to repair and I'll need a solution soon before I've replaced everything on the board haha.
  15. Double Post, please delete...
  16. Double post, please delete...
  17. Hey everyone, I've got a fully-restored SE/30 that is giving me screen issues. It's the one from this thread: https://68kmla.org/forums/index.php?/topic/30045-full-recap-of-my-new-se30-with-many-pictures/ I've attached a video of the screen issue I'm having (can upload to YouTube if the attachment is an issue for you guys). The screen twitches intermittently. A nice sharp slap to the side of the machine makes it go away for a while. Here's what has been done to the analog board so far: -Full recap of all electrolytics -C15 replaced with film capacitor -Yoke connector resoldered (all old solder completely removed) -Flyback resoldered (all old solder completely removed) Not sure where to go from here. What other cold solder joints could cause this issue? IMG_1303.MOV
  18. Hi, I'm a vintage macs loving and I'm very proud of fix a lot of 8 different classic macs (reading the great books of Larry Pina!!!). I have skills in soldering and I'm learning about electronics by practice. Until now, I have a high degree of success!! until now. I'm the owner of a 512Ke that shows a lot of tiny vertical lines at startup. There's sound, no friendly bong, just something like "grrrrr" no matter. I try to fix it and I saw my first surprise. It has a macsnap 3 memory and scsi expansión cards. The scsi card was free inside the box, no attached to the roms socket.I atached the scsi card, and resolder the yoke conector J1. No success, same result. I'm think in a memory or ROM error, so I think that it would be a great idea to swap the logical board with the logic board of a mac Plus. I have a 220 V macPlus and my 512ke it's a 120 V, but I think that probably it works. I'm seeking in the internet and i didn't see nothing to not to do it. Well, I changed the logical motherboard and turn it on. The fuse blow up. I was worried because I don't know why..After check out the motherboard, and saw no damages (at least at first sight), I thoght that I must changed the power supply and connect the 220 cable, not the 120 one (I have it together..) so I replace the 2,5 A fuse with the one that I have 5 A, thinking that everything it would be ok... mistake... When I powered it on, a Little burn was in the neighborhood of the Q10. 4 or 5 resistor burned and the q10 literally annihilate .. jejeje It was a very, very dumb mistake, I know.. Anyway, I would like to question you about this things.. - Is there any problem trying to do what I've done, swapping the logical boards?? - If no, what do you think about the first fuse crash?? Changing the voltage sources?? other reason?? - What do you think about the second problem?? Caused by the first one?? the same reason of the first crash?? Now, I'm going to try to fix this little disaster, and I trying to think about the components that I need to change, in order not to continue breaking my little boy.. I think to change these components: R60 1k R44 100 R45 1K R46 22 1W R47 1.5 R48 100 R49 1.5 Q10 E0122 EO121 EO102 SD8335 CR400Y ECG5589 E0102YA NTE5400 SILICON CONTROLLED RECTIFIER Q9E 2N3906 o ECG159 o 2761604 o 2N4403 o 276-2023 (T-PNP, 1A,. 6W, TO92) C39 470 mfd 10V 85C U3 4N35 ECG3041 (IC, 6-p, optoisolator, 2500V) CR28?? CR29?? Do you think that I have to change another components?? The bridge diodes?? Thank you very much for your patience, and I would be very appreciatte your help By the way, when I'll fix the issue I'l need your help with the macsnap and the vertical bars!!! Thx, Jorge
  19. joethezombie

    SE/30 Analog Board Re-Cap, bottom

    From the album: Macintosh SE/30

    Solder-side view of the SE/30 analog board. The capacitors have been removed and the pads cleaned up, waiting for the new caps to arrive from Digi-Key.
  20. joethezombie

    SE/30 Analog Board Re-Cap

    From the album: Macintosh SE/30

    All capacitors have been removed from the analog board and is now ready for the replacements to be installed. Copious amounts of electrolytic fluid has been cleansed from the board. The pots were sprayed out with contact cleaner, and exercised back and forth full-stop. Additionally, the (very noisy) fan has been replaced with a Nanoxia Deep Silence 60mm fan, NDS60-2000.
  21. I am in the process of tearing down my iMac G3 with the purpose of shipping out the motherboard, analog board, and PSU for recapping. I was able to get the motherboard and PSU out after a good deal of effort, and was just starting the final push to remove the analog board. I was able to remove all of the connectors except for the red pair of wires connecting the screen and focus control to the CRT board (shown between my thumb and forefinger in the below imgur album): http://imgur.com/a/bBdN6 I can't seem to find any way that these wires can be disconnected from the screen/focus controls, and the controls themselves appear to be soldered directly onto the analog board, so the nearest thing I can tell would be to disconnect the wires from the CRT board itself. Is this the preferred way of removing the analog board from a G3, or is there another alternative? I don't want to pry into the CRT connections if I can help it but will have to do so if there is no other way.
  22. From the album: Macintosh SE/30

    https://68kmla.org/forums/index.php?/topic/28383-se30-se-analog-board-damage/ Resistor (R29, 2W, 12Ohms 5%) Linear Voltage Regulator (U3, 7905 -5V 1A)
  23. From the album: Macintosh SE/30

    https://68kmla.org/forums/index.php?/topic/28383-se30-se-analog-board-damage/ Resistor (R29, 2W, 12Ohms 5%) Linear Voltage Regulator (U3, 7905 -5V 1A)
  24. From the album: Macintosh SE/30