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About BadGoldEagle

  • Birthday 04/18/1996

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  • Location
    Weissach, Germany
  • Interests
    Compact Macs and post 1998 Macs (PPC and Intel)

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    Automotive Engineer

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1808 profile views
  1. BadGoldEagle

    BGE's take on the Quadra 900/950 ATX PSU Mod

    I don't mean to sound rude but wouldn't this conversation be more appropriate in a PM? In other news, I've decided to use an ATTiny85 instead of the Nano. The boards will come with a preprogrammed chip and I'll offer programming services after the original run of boards is sold out (if there is enough demand outside of the 68kmla, I'll order a new batch of 10). A set will now cost $10 but you won't have to buy the controller so in the end things will be cheaper for you guys. This will reduce board clutter as well. The ATTiny85 is a DIP8 IC while the nano takes about as much space as a DIP30 chip (which does not exist, so I would have had to use a DIP32 socket for the Nano and things wouldn't have been aligned...) Current fan controller schematic: NB1: The relay bit is still entirely optional. NB2: The pot will be replaced by a trimmer. It'll be about $3-4 cheaper. NB3: The LED indicator circuit will probably change as I don't think a single 20mA LED will be bright enough to be seen through the vents at the back (it will be on only if something goes wrong, otherwise it'll be off). The rest of the schematic shouldn't change much now. How this works: - Pins 3 and 7 are the inputs: The pot (pin 3) will allow the user to set the minimum fan speed (lowest position=50% and highest=100%). Pin 7 has the thermistor which will make the fan speed up/down linearly as the temperature increases/decreases. Still haven't decided on what the curve should look like. Should the max. temperature be lowered to 75C? Only actual testing will tell. - Pins 5 and 6 are outputs. Pin 5 will go straight to a MOSFET, which in turn will modulate the fan's ground and therefore its speed. Pin 6 will be used for the LED indicator circuit. Now on to write software for the thing! I'll code this for Arduinos 'cos that's just easier.
  2. BadGoldEagle

    BGE's take on the Quadra 900/950 ATX PSU Mod

    Great to hear @Ton but given that the engineer I talked to before deciding to do this mod repairs PSUs for a living and tests them at full load for 24 hours before calling them fixed, I wouldn't declare victory just yet... My recapped PSU died during a small stress/smoke test. My plan was to leave it on idling for 3 or 4 of hours but it didn't even pass the two hour mark... But your problem is interesting: it means that computers of this era (early 90s) are starting to suffer from tantalum cap failures. Instead of leaking like the electrolytic ones do, those just explode. ________________________ And now, back to the subject at hand. I have once again decided to change the fan controller (this will be the last time, as I'm sure this will work this time). I just can't get enough from the 555 to do everything it want it to do. I'll now be using an Arduino Nano board (it costs from 1 to 7 bucks depending on who you're getting it from... even clones from China should do the job). I chose it because: 1/ It comes in a PDIP like package. Either solder it to the QuadrATX DC board or install it in a socket. You don't need a hot air station... 2/ It's configurable, because it'll be running a bespoke sketch (read program). If I mess up the code, I can still change it without having to alter the DC board. 3/ It's REALLY easy to flash. Get the free Arduino App for your Mac/Linux/PC, open it, plug in the Nano with a USB cable and hit upload. ANYONE CAN DO IT. 4/ If it dies, there's plenty more available 5/ It's easy to program for and it's got quite a sizable community. 6/ The fan controller part of the schematic is now a lot easier to understand and the circuit won't take as much space on the DC Board as it used to. 7/ Isn't that enough? More to follow...
  3. BadGoldEagle

    Color Classic Restore

    Good to know. So that’s probably why mine won’t start anymore. I know I should have recapped it by now but that’s just one of the many issues it currently has.
  4. BadGoldEagle

    BGE's take on the Quadra 900/950 ATX PSU Mod

    The real hard work would have been trying to fix these old beasts, not gutting them... but at least, like Geekdot said, it’ll run cooler, be more reliable and easily repairable in the future...
  5. BadGoldEagle

    BGE's take on the Quadra 900/950 ATX PSU Mod

    @olliec420 Parts. 8 bucks would be a little too cheap for a complete mod... those boards will be BIG. Instructions/files will be free once I finish it. Hopefully I'll have a new schematic ready next week.
  6. BadGoldEagle

    3D Printed SE/30 ROM Clips

    Nice work. Now do one for the RAM slots that’ll cover the entire length
  7. Definitely following this one. I too had started listing the custom chips on the SE/Pluses, but you took a step further and that's impressive work! Keep it up @Kai Robinson It'd be particularly useful to reverse engineer that RTC chip. The ATTiny85 seems like a great place to start. The SE/30 uses the same chip and and it's generally what makes these boards impossible to repair once they've been bombed.
  8. BadGoldEagle

    BGE's take on the Quadra 900/950 ATX PSU Mod

    Thanks @mietek 22uF, 16V. Casing is probably C or D.
  9. BadGoldEagle

    BGE's take on the Quadra 900/950 ATX PSU Mod

    When you're dealing with tantalum caps, only replace the ones that are damaged. The rest of them (for now at least) are ok. I don't remember on top of my head what value that cap was and my 950 is currently buried under a pile of stuff... Maybe someone else can help? I think your PSU is what blew that cap.
  10. BadGoldEagle

    BGE's take on the Quadra 900/950 ATX PSU Mod

    @mietek sure thing... and that makes 10! Now, unless someone wants to buy 5 more, I'll stop the "pre-order" here. @Ton I feel your pain. It was pretty much the same thing for me but instead of RAM that was with the DOS card. And the damn PSU also tried to kill me (to be honest it was probably my fault). I'm really starting to think there aren't any original working PSUs left... And now, for the less fun part. A couple of weeks ago while casually browsing the web, I noticed that the MIC502 supplies aren't as high as I initially thought. I'll have to rethink the fan controller yet again (only for the 5th time). This on top of other life related issues, Apple ditching intel (which in itself almost caused me to fall into a depression), lead me to pause this project for a bit. I need to sort out the life stuff first, but when I'll get back to it (hopefully in the next couple of weeks), I'll most probably pay someone to design the new circuit for me. I just can't handle another failure emotionally. This time, I'd like to use a 555 PWM generator type of circuit, but I can't figure out which one (there's at least 4 different variants) to choose. I'd like it to be still temperature controlled, and to have a minimum speed threshold (duty cycle) of about 40% so that the fan can't possibly stall. More to follow...
  11. BadGoldEagle

    BGE's take on the Quadra 900/950 ATX PSU Mod

    I've had to revise the fan controller bit again... Big thanks to the guys over at eevblog.com for their help. Although this still hasn't been 100% approved/verified, it's looking pretty good now! We've mostly redesigned the LED controller circuit - Now we won't be frying op amps with voltages that are too high at the inputs (updated R8 and Vcc for U1). - I've switched to an LM393 (U1)as this is a proper comparator. The 358 wasn't. - Inverting Schmitt Trigger built-in (R5, R6, R11, R12). LED will light up at 84°C and will turn off at 79°C. Just like your engine waring light, it should never light up. If it turns red, please stop carefully and contact your nearest service center (i.e. me). FYI If you don't want temperature control just remove TH1 and replace it with a 10k resistor. If you don't want the Overheating indicator circuit, just leave R5, R6, R8, R9, R11, R12, U1, Q3 and D1 out... this is not recommended but the fan will still work without it. Leave those components out at your own risk. Edit/PS: I'll probably buy a bench supply and a breadboard to test this circuit before I send the boards to production...
  12. BadGoldEagle

    BGE's take on the Quadra 900/950 ATX PSU Mod

    Hallo Bunsen Thanks a lot for pointing out what it's called. The documentation will look a lot more professional now. Zur Info, diese Dinge heißt 'ne Durchführungstülle. En Français (I'm a french dude living in Germany after all...), ça s'appelle un oeillet ou bien un passe-fil... And yes, this mod is only compatible with Quadra 900/950s as they are (AFAIK) the only Macs with a 24 pin Molex Mini Jr (ATX motherboard) connector. In other news, I've had to scrap the previous fan designs (they weren't compatible with high wattage fans and wouldn't work with all PSUs...). It's now fully PWM and has a thermistor for fan control. A LED lights up once the thermistor reaches a temperature of 80°C/176F. It's still work in progress but it's lookin' good!
  13. BadGoldEagle

    BGE's take on the Quadra 900/950 ATX PSU Mod

    Proposed Comparator/Controller circuit: I had to take into account the different 2/3-pin fan control strategies (namely, PWM and Modulated ground) for the ATX PSU fan connector because since this isn't standardized, it has to work with them all. That's C1, R5-8 (on the right) and Op Amp #3. The other three Op Amps are used to compare the Potentiometer fan voltage to the ATX PSU fan signal. For those with Op Amp background, there's two comparator and one follower setups. Two power transistors Q2 and Q3 will effectively switch the two fan signals either on or off based on the table in the post above. I added a slide switch to disable/enable the comparison circuit (it disables the LM324's Vcc input and the circuit will function like before ie Potentiometer control only). For those who don't want to bother with this whole thing, just short 5 and 6 on SW1. You don't even need to buy the switch, I'm currently thinking about adding pads like on the IIc to short those pins: © Big Mess o'Wires Edit: For once, it was easier done than said. Kicad has some built-in solder jumpers! I'll double check everything again and I'll update the PCB.
  14. BadGoldEagle

    Radius Pivot SE/30 color monitor requirements?

    Can you post a picture of your card? Most SE/30 Pivots can only do greyscale. The color cards are pretty scarce. You should also check your ColorSync profile. Maybe it’s set to some odd greyscale monitor... My IIsi Pivot works on a wide range of monitors, including TVs with VGA inputs... so I don’t think the monitor is the problem here. FYI, there’s only one version of the IIsi Pivot (which can do color) and it’s “compatible” (to some extent) with the SE/30.
  15. BadGoldEagle

    BGE's take on the Quadra 900/950 ATX PSU Mod

    And the checks are done! Phew! I am still not particularly proud of my fan circuitry. I am currently thinking about upgrading my dumb controller to at least PWM. But I am also tempted to go with a full-blown temperature controlled circuit that reuses the PSU's built-in controller... but for someone with limited electrical engineering background like me, that's rather complex. Here are my (rather basic) system requirements: The minimum speed setting shall be controllable with a potentiometer or when possible trimmer. The fan speed while unit is in operation shall be regulated automatically based on the PSU's internal temperature. The actual fan speed shall be defined as the maximum between the temperature controlled speed and the minimum fan speed, whether the unit is on or not. The fan shall be able to run at a fixed speed if the PSU's built-in controller is not plugged in. Truth Table: FAN SPEED Cold PSU Hot PSU Quadra ON Always on and at minimum ATX controller OR minimum Quadra OFF 0 ATX controller* * May be used to cool down the PSU after the Quadra is switched off.