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elemenoh

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  1. I have a graphite 17" CRT display (M6496) that will degauss when plugged in and cycle the LED from amber to green once per second. It does not produce an image when plugged into a working Mac of its vintage. The analog board looks okay from a visual inspection. No leaking caps, no board damage, no obviously cracked solder joints. Any idea what might be causing that issue? There's no mention of what a flashing LED means in the Service Source manual.
  2. elemenoh

    DuoDock power supply issue

    I swapped in a known-good MLB and had the same symptom. Since I had them on hand I also replaced the 470µF/25v and 1,200µF 10v caps, but the issue remained. The smaller caps are a PITA to get out. It was hard to get the channels clear even with solder wick and lots of flux. Here's a cap map in case it's useful to anyone else.
  3. elemenoh

    StyleWriter Capacitor List

    I have a StyleWriter that would power up for a couple of seconds and then power off. Tearing it apart revealed leaking caps on the logic board. Here's a map and Digikey cart in case it's helpful to others. https://www.digikey.com/short/z829n5 In my case, the 100µF caps looked worst and I happened to have them on hand. After replacing them, the printer powered up okay.
  4. elemenoh

    DuoDock power supply issue

    This DuoDock just clicks and spins the fan briefly when powered on. 5v measures okay but 12v only comes up to about 2.5v before coming back down to 0. I've replaced the 100uf caps at C24 and C28 and (since one was bulging) the 330uf caps at C12 and C19. The other caps at least appear okay, but haven't been tested or swapped. Should I just replace all remaining caps or focus triage somewhere in particular? IMG_1755.mov IMG_1753.mov
  5. This 512K is chiming, but doesn't show any video. 5v/12v rails test okay. Swapping in a known-good analog board resolves the problem. A faint high pitched buzz and ticking can be heard, but it's hard to tell where it's coming from. The best I can tell is that it's coming from T3, but could be wrong. T3 also has a blob of smelly black something on it, but other working ones have all sorts of weird goo on them. Dead Mac scrolls indicates this sort of issue might more likely be the flyback transformer. Is that the most likely culprit or should I look further at T3/elsewhere? IMG_1712.mov
  6. I figured out that BT478KPJ66 at UA2 is the RAMDAC. Reflowing it didn't change the symptom. Video with a radius Nubus card works okay and helped to confirm that the screen shots taken with internal video were clean. Is it correct to suspect that BT478KPJ66 itself is probably faulty or are there other things to check first? There's currently only 1 BT478KPJ66 on eBay with an asking price of $20. Is there a better source for cheap replacements?
  7. Screenshots are clean. Which chips are the RAMDACs?
  8. I tried running tech tool pro this morning and got a weird error on the RAM test. It said something like there's not enough memory to run the test. But then it ran and passed all of the other tests (PRAM, math etc). Here's a photo of the board around the soldered memory. I'll try reallocating the memory per @Trash80toHP_Mini's suggestion. If I need to replace the soldered RAM I might as well upgrade. What sort of spec should I be looking for? Thanks for the help!
  9. Both before and after recap, this IISI shows video distortion. The same monitor and adapter on another IISI works okay. The board hasn't been fully washed yet, but it was pretty clean to begin with and I scrubbed it down with IPA pretty well during the recap. Is there a particular part of the board I should focus on? Any other tips? IMG_1538.mov
  10. Disk Warrior will launch on SE/30, but the rebuild and graph buttons are off screen and can't be pressed. Typing return also doesn't start the process. Hopefully this is a dumb question, but is it possible to run Disk Warrior at 512x342?
  11. I recapped a 6200CD yesterday and couldn't find a list online. So here it is: 7x 47µf 16v (Replace with Tantalum Electrolytic Size C) @ C7,C8,C10,C34,C45,C46,C51 3x 100µf 6.3v (Replace with Tantalum Electrolytic Size C) @ C6,C9,C25 1x 22µf 35v (Replace with Tantalum Electrolytic Size D) @ C14 This is the first time I've come across a 22µf during recapping. They're relatively expensive too. A tip for removing C8, C14, C45 and C46: Place or tape (with Kapton tape) a couple of razor blades against the nearby plastic connectors to act as a heat shield so you can remove the caps with hot air without melting everything nearby. Digikey cart for the above: https://www.digikey.com/short/zqjqn3
  12. What are the replacement options, if any, for melty rubber feet for the pizza-box style case of the LC series, Performa 475, Quadra 605 etc?
  13. elemenoh

    Macintosh Classic II with missing ROMs

    I have 2x Classic II’s but with the 2x40 pin ROM setups. One of the ROMs is bad so I’m looking to program a new set. What type of blank ROM would work in those and what sort of programmer would be needed?
  14. elemenoh

    Vertical lines on Classic II

    This Classic II originally had 16 vertical bars on boot. After a couple of thorough scrubbings with IPA it stills displayed vertical bars but across the whole width. The caps were replaced today and the same symptom persists. The bodges were to deal with a couple of pads that lifted. Any suggestions for where to look for trouble?
  15. The battery in this Quadra 650 wreaked a decent amount of havoc, including rotting off one of the nearby transistors at D4. Can someone identify what type it is? Any other tips for restoring the affected area?
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