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trag

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    Austin, TX
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    Model & Amateur Rocketry

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  1. I'm not sure what the above means. Can you be more specific.
  2. Anyone remember the inductance range that Wally measured back when? The linked thread seems to be one of the one's lost in the software update. I have not made any meaningful progress -- as with all my projects. The (ICF) 94-530-1024 at https://www.surplussales.com/Inductors/Ind-SlugTu/Ind-SlugTu-4.html is probably the best candidate I've found for a coil form. I was hoping that one or two of these (ICH) SLUG-4 at https://www.surplussales.com/Inductors/FerPotC/FerPotC-1.html will work for the ferrite slug adjustable core. I don't have a current supplier bookmarked for Litz wire. I recommend reading the Wiki article (assuming it's still there) to learn about the parameters involved. All that should be necessary is to take one of your broken inductors, carefully unwind it (maybe mark a stripe down the outside) and count the windings. Then examine the wire under magnification to determine the number of conductors in the bundled wire. Litz wire comes up pretty easily in searches, or it did a few years ago. The trick is knowing what you need. Then wind the same number of coils on a form in about the same pattern, insert one or two of the ferrite cores, and see if it works or works with adjustment. This link https://www.electronicsurplus.com/inductors/inductors-coils/page/3 also has some parts that might be good candidates -- if I knew the inductance range. But the 7-142 might be good even if one must unwind it and rewind it with Litz wire. It looks like the form is pretty similar in shape.
  3. Additional information here: You may want to just pull the part number from the DigiKey link and use it to find the part at your favorite European supplier.
  4. IT's kind of embarrassing I had forgotten this but CC_333's comment reminded me. I actually had/have one of those exceptions. I didn't think of it because I've seen the pin1 problem many many many times before. But in the exception, the screen would cut out like yours does. Eventually banging the side didn't do anything. But if I powered up with the case off, and gripped the rear edge of the analog board and pulled outward until it deformed a bit, video would come back. At the time (like 20 years ago) I was flummoxed. Now days, this would suggest to me to remove the analog board and desolder and resolder pretty much all of the joints. I might try examining it under magnification for bad joints, but those can be very difficult to spot.
  5. Not really. The goo doesn't travel that far. Check the vias around the capacitor locations. Vias are particularly vulnerable because they are low lying spots (like pot holes) where the goo can accumulate adn work its evil destruction.
  6. If it is the only drive on the cable and it is a Western Digital drive, it needs to be jumpered to "Single". IIRC
  7. Vias will look perfect to the eye even when they are totally corroded. Get something like a dental pick or a straight pin and try poking the solder in the vias. If you can poke into it then capacitor goo has eaten the solder in the via and probably the copper lining as well. This is what happened to my IIci back around '97. It looked fine, but when I started probing vias with a pick, most of them were hard, but one was solft, but still looked fine. To be complete, to a really well trained eye that via probably won't look perfect, but the difference is almost impossible to detect unless you've seen it before.
  8. It is conceivable that it is the SWIM chip, but in the vast majority of cases the problem is a rotted trace from the cap goo, or residual cap goo hiding under a chip, but across connections that didn't get cleaned off. I would try another thorough board cleaning first, and if that doesn't work, start tracing connections from the SWIM chip with an ohmmeter. A schematic is helpful for the latter.
  9. I wonder if the issues with SSDs has any similarities to what this fellow found in the PB150: http://www.cosc.canterbury.ac.nz/greg.ewing/hardware/pb150/
  10. Good to know which one they are shipping and that they work. With luck that seller is consistent about which version ships.
  11. No display, restored or intermittent with left side tapping, is always pin 1 on that connector. There's probably some exception, but so rare.
  12. I think I've found the X100 family PDS connector part number. I'm on a little bit of a mission to identify the part number for the cache, ROM and PDS connectors on the X100 and X500 machines. Anyway, this one appears to be a Burndy CEE2X91S-V7Z14 and there seems to be stock here: https://www.connectorpeople.com/Connector/BURNDY/C/CEE2X91S-V7Z14 No telling whether the above is a surface mount of a through hole part though.
  13. Don't know if it's true in your case, but in my experience, PLCC32 sockets often don't work if the chip is pressed to the bottom of the socket. Try inserting the chip until it is securing held by the pins, but not all the way at the bottom of the socket. IIRC, get the top of the chip flush with the top of the socket, but not pressed down to the bottom of the socket. I have this issue with my PLCC32 - DIP adapters.
  14. I think it's been too long since I looked at the PCI spec. As long as all the signals needed for a PCI slot are present, it should be trivial. Might check that REQ, GNT, are unique to each slot on the riser card. And IDSEL? I can't remember if that's a per slot or a bus signal. Also would be interesting to know whehter the INTs are tied together but unique per slot. That's how they are on X500 and X600 machines. Each slot has its own unique INT, but all four INT pins in the slot are tied together to that single INT. There's something different about the 6X00 machines that make them not play nice with PCI-PCI bridges. Oh, the X500 and X600 machines have the same problem, but one must have two levels of bridge to see it. On the 6X00 machines, often putting in just a card with a bridge on it is enough to cause issues. Could also be that the PCI controller in the logic board chipset was built with an internal PCI-PCI bridge. Apple's first PCI implementation has a serious bug that doesn't handle multiple levels of PCI bridging properly. They didn't bother to fix it in the X600 machines. I don't know if they fixed it in the Beige G3 -- of course the PCI controller in that machine was designed by Motorola, so that may have solved it.
  15. What Dog Cow said. Except for some microcontrollers and a few other oddballs, CPU have (a) pin(s) for one or more clock signals. The incoming clock signal controls how fast the CPU operates. Changing the CPU and not changing the clock signal just gives you a different CPU operating at the same speed. There are all kinds of edge cases and exceptions. And, of course, with slightly more modern CPUs the CPU operates at some configurable multiple of the incoming clock signal. But for the 680x0 family, the above is accurate.
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