68kMLA Classic Interface

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Reminder to NOT turn on an old Mac that you found (PHOTOS INSIDE)
Posted by: ben68 on 2018-08-02 19:05:17 How many SE/30s does one person need? Apparently, always more! (Somebody stop me.) I picked one up today, and the owner wanted to plug it in and show me that it worked - I said, "That's okay. I'll buy it even if it doesn't work." So I get it home, open the back, and find a LOOSE hard drive - someone had TAPED it to the floppy sled. Then I pulled the logic board, and fortunately, the battery was intact, but there was something missing. Also, there was an odd bracket between the battery and the ROM: Odd no? I'm still not sure if that's glued in or what. Also, notice something missing? It has a CRT that I didn't recognize too: Non standard? Made me wonder if it had been replaced - or maybe the later SE/30s came with a Matsushita. And as I was cleaning up the board a bit with C3H8O, two of the capacitors jumped ship, so I decided to pull the rest of them. And I was expecting 11, so was surprised when: TEN capacitors. Is this just a later logic board? Where's #11? Well, as you saw above, C12 made an earlier exit. Also just noticed the odd man out in the RAM - I wonder if the original owner ever had RAM issues due to that 9 chipper. Anyways - just a reminder not to plug it in and see what you get. Here are some more photos of the board and such: How can you tell what size RAM that is? I can tell on a PC from 1988.
Posted by: superjer2000 on 2018-08-02 19:33:43 I don't recall ever seeing a Matsushita either. Also I don't think I've seen a resistor on the test connector on the logic board edge before.
Posted by: superjer2000 on 2018-08-02 19:36:17 Also how is the crt connected to the flyback? It looks like the crt cap is connected to the ground lug bold and then glued(!) to the CRT.
Posted by: ben68 on 2018-08-02 19:46:28 I don't recall ever seeing a Matsushita either. Also I don't think I've seen a resistor on the test connector on the logic board edge before. I noticed that too - not sure why that's there - maybe it has to do with the CRT. The flyback Tx is all standard.
Posted by: superjer2000 on 2018-08-02 20:21:27 I don't think glue on the crt is standard - can you get a wider angle pic of the unit including the analog board?
Posted by: ben68 on 2018-08-02 20:38:41 It's either a standard flyback Tx or a low volume nuclear device. Matsushita = Panasonic - who knew?
Posted by: Bolle on 2018-08-02 21:25:34 That little bolt between the battery cage and the ROM SIMM holds the ROM in place. The tabs on the socket are probably broken or worn out. Actually a smart way to keep it in, going to have to try this myself. It looks like the anode is on the side of the tube that’s facing the analog board. On some CRTs you had a metal grounding strap hooked around the the tube, that’s what the little glued on wire is suppoed to do I would guess. Resistor on the test connector is normal. I have seen that on a few boards already (on a fee different Macs, not only SE/30s) It is a pullup resistor for the serial line. For the SE/30 that resistor is in the schematics but it is nowhere on to be found on the logicboard. They must have left it out on later models as it seems is not needed.
Posted by: EvilCapitalist on 2018-08-03 06:14:47 I'm wondering if the previous owner had some of the RAM slots replaced as well. In all the ones I've seen the RAM slots were all the same color but your pic shows half white and half black. That little bolt between the battery cage and the ROM SIMM holds the ROM in place. The tabs on the socket are probably broken or worn out. Actually a smart way to keep it in, going to have to try this myself. I seem to recall someone saying they needed to do that with the ROM-inator II, though I can't for the life of me remember where I read that.
Posted by: Bolle on 2018-08-03 13:21:22 I'm wondering if the previous owner had some of the RAM slots replaced as well. In all the ones I've seen the RAM slots were all the same color but your pic shows half white and half black. I have a board that’s the same way, pretty sure it came from the factory with two different colors. The solder spots on mine are definetly factory-grade on both RAM banks. I would guess they went out of one color right in the middle of populating one board.
Posted by: techknight on 2018-08-03 15:57:27 Question. Where did you get this? Reason why I ask, is I recall doing a SIMM mod like that years and years ago to one I sold in a yardsale and I remember it looking exactly like that. But the CRT and the "mods" there were not there of course. So who knows.
Posted by: SE30_Neal on 2018-08-03 22:42:38 Genius mod for the rominator, i may do that to mine
Posted by: Unknown_K on 2018-08-04 11:14:46 Hot glue gun will hold them in place also (and you can peal that off). I tend to not turn things on without taking a look inside (or if anything is rattling from shipping).
Posted by: ben68 on 2018-08-04 11:36:05 It's from a fellow in Sacramento. The RAM is factory, and the ROM has one broken clip - hence the brace. Now I have three logic boards to recap (and only one set from Trag). Any recommendations for getting the oxidization off the chip legs? I tried a toothbrush and isopropyl alcohol, but the discoloration remains. I'm still too chicken to put it into dishwater and scrub it.
Posted by: Unknown_K on 2018-08-04 12:00:34 Plastic RAM SIMM holders seem to have that issue of breaking tabs which is why the later versions have metal tabs.
Posted by: SE30_Neal on 2018-08-04 12:33:05 I got my sister to solder blobs on the connectors at the bottom of the rom, now fits snug and works a treat when i fitted it today. Shame the rominator doesnt like macos 7.5.5 on se/30 thats Another story though.
Posted by: SE30_Neal on 2018-08-04 12:40:50 It's from a fellow in Sacramento. The RAM is factory, and the ROM has one broken clip - hence the brace. Now I have three logic boards to recap (and only one set from Trag). Any recommendations for getting the oxidization off the chip legs? I tried a toothbrush and isopropyl alcohol, but the discoloration remains. I'm still too chicken to put it into dishwater and scrub it. You know the liquid cleaner for jewellery Why not try that it made my wifes ring really shinny and tried some coins and they looked new within 30 mins
Posted by: techknight on 2018-08-04 17:17:20 It's from a fellow in Sacramento. The RAM is factory, and the ROM has one broken clip - hence the brace. Now I have three logic boards to recap (and only one set from Trag). Any recommendations for getting the oxidization off the chip legs? I tried a toothbrush and isopropyl alcohol, but the discoloration remains. I'm still too chicken to put it into dishwater and scrub it. It would be interesting if my yard sale mac all these years later wound up there somehow. I remember doing this mod to hold the ROM SIMM in. But everything else thats happened must have been afterwords. Then again, it could be a different one. Who knows?
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