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dontdoxmeman

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  1. dontdoxmeman

    Counterfeit 68040 (L88M mask revision) from eBay

    Got some 3M 8810 thermal tape (https://www.amazon.com/gp/product/B00QSHPH8E) and a little fan/heatsink combo (https://www.amazon.com/gp/product/B07ZTM539S) and installed them in my Mac. Hooked up the fan to the 5V hard drive power and stuck the heatsink on the CPU, and it all fits perfectly. The fan is probably overkill but it's quiet enough and consumes very little power so I don't really care.
  2. dontdoxmeman

    Counterfeit 68040 (L88M mask revision) from eBay

    Most of the 68040s that were in Macs were the XC models. Motorola took a long time to fully qualify the 68040 as a MC part according to something I read online a while ago. The XC chip in the photo I took is the original cpu from my Quadra 605.
  3. Bought an MC68040 to upgrade my Quadra 605 from this eBay listing: https://www.ebay.com/itm/1PCS-MC68040RC40A-New-MPU-ColdFire-Processor-RISC-32bit-40MHz-179-Pin-PGA-Tray/323076959423 The image showed the L88M mask revision which is supposed to be the one that runs nearly cold. I figured it was probably not really a L88M revision chip, but figured why not since it's eBay and I can get my money back if necessary. Well, the good news is it's a real 68040 according to MacBench, and the bad news is it runs about 15 degrees C hotter than my old XC68LC040 CPU when aiming an IR thermometer at the CPU. The screen printing on the eBay CPU looks less fake than the eBay listing image did, but still dodgy and fake. I'll be opening a dispute with eBay, but in the event that I end up keeping this chip (or getting another one that runs hot) does anyone have any heatsink recommendations?
  4. dontdoxmeman

    Not sure if Trinitron CRT worn out, or if it can be restored

    As an update, I tried hooking up the board of my better M1212 to the CRT from the worse one, and after adjusting all the convergence/etc I still couldn't get the focus any better than it was. I'm thinking this may just be a high-hours CRT. Maybe some day I'll try recapping the board, for now I'll just use the nicer CRT.
  5. I have two Macintosh Color Displays (M1212). These monitors have Sony Trinitron CRTs inside. One of them is still pretty bright and sharp. The other, when I received it, was quite dim even when I turned the front knobs up. I eventually took it apart and adjusted the G2 to where the brightness was decent enough, but increasing G2 as I did causes the screen to get a soft focus. I have the focus potentiometer turned as far as it will go, which does improve the focus a little, but it just can't get anywhere near as sharp as the other monitor. Rather than go down a wild goose chase replacing capacitors, I'm going to swap the tubes between monitors to try and confirm that the tube itself is the problem. But regardless, does anyone have any last-ditch ideas for squeezing a little more life out of this Trinitron? (CRT rejuvination? Modifying the board to increase the focus voltage?)
  6. dontdoxmeman

    SE/30 video problem: groups of scanlines being displayed twice

    I haven’t recapped it yet. Obviously needs it, being 30 years old, and the audio is very faint which is a telltale sign at least those caps are dying. Tonight I took it all apart, saw a little bit of oxidation/possible corrosion on some SMT chip pins around the video area of the motherboard. Traces still look quite good though, no obvious capacitor juice anywhere. Tossed the dead lithium battery timebomb, did some quick cleaning with isopropanol and put a little deoxit on some of the more corroded chip legs. Analog board looks pretty immaculate, didn’t do anything to it yet. Reseated the simms and left the second bank of ram out this time. Connected it back together and turned it on, and already saw quite a bit of improvement! The heavy flickering is still there and quite variable, but I’m not seeing nearly as many repeated or missing scanlines. However, after leaving it on for a few minutes it got a little bit worse again (though still not as bad as before). I’m pretty optimistic now that a recap will fix this. Will update whenever I get that done.
  7. Finally graduated from lurking, and I'm hoping for some repair advice. My SE/30 is showing scanlines repeated and flickering. Has anyone encountered this before? I took a video, you can see it on reddit:
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