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Macintosh SE/30 logicboard recreation (thread revival)

Trash80toHP_Mini

NIGHT STALKER
I recently saw this video on YouTube where they just cut the entire floor out of the socket. It certainly makes it much easier to solder but presumably the socket floor is there to provide mechanical integrity so I worry this might not be a great solution. I prefer the way @robin-fo did it by working around the floor as much as possible, provided of course that the solder joints themselves are good enough.
Yes, the support keeps the chip at the proper level in the socket for good contact. Don't recall offhand who reported on it here. As I understand it, problems might arise if left missing.
 
My specimen is slowly nearing completion after an initial 12 hours shift today. I decided to use PLCC sockets to be able to easily transfer the chips to a second board which I am planning to populate, without having to desolder them a second time.
Very nice to see that other people are working on the same project. Did you order the green PCB from JLCPCB with the backside already presoldered? If so, would you share a picture please?
I´m not sure if should order five naked blue boards or five with backside pres.
You did a good solder job, please keep us informed (y)
 

robin-fo

Well-known member
Very nice to see that other people are working on the same project. Did you order the green PCB from JLCPCB with the backside already presoldered? If so, would you share a picture please?
I´m not sure if should order five naked blue boards or five with backside pres.
You did a good solder job, please keep us informed (y)
Yes, the backside is pre-populated (though some inductors are missing; their values are unknown as far as I know).
I also would have preferred purple or black boards, but I thought that there is already enough work to do on the upper side…
 

robin-fo

Well-known member
Here is one of my two remaining spare boards
 

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robin-fo

Well-known member
Some further progress…
My new PLCC puller tool was really worth its price: It was invaluable during the desoldering of the DIP chips…😅
 

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daanvdl

Active member
@superjer2000 haha, I’d be quite happy to stop my day job and refurbish SE/30 boards instead but I suspect it might be a bad business decision! These things are a labour of love I think, rather than a career prospect! 😅

Re using new connectors, in my case the PDC socket was quite badly corroded by the battery bomb so a new one certainly was a necessity. But also, and more generally for other connectors which have soldered mechanical support tabs like the ADB, SCSI, Floppy and Serial connectors, it’s just a hassle to harvest them without causing damage to them in the process. I removed the 25 pin D connector for the external SCSI from my donor board but it was a real struggle to both remove the solder AND get the mechanical fixing posts to disengage. In retrospect probably the way to do it is to just cut most of the PCB away from the connector with a dremel or similar tool and then remove the PCB fragments with hot air or desoldering wick etc.

But even if you succeed, best case you end up with a 30+ year old connector with contact oxidation, mechanical wear and tear and cosmetic defects which seems a shame on what is otherwise largely a “new” board. Now, if you’re on a tight budget or trying to make a profit from this endeavour then you might make different choices because these connectors are not cheap. I’m fortunate this is more of a hobby.

I should also mention that, although I ordered the connector parts from mouser according to the SE/30 BOM spreadsheet, I have not yet received them so can’t confirm personally that the parts in my mouser basket are 100% correct. This includes the PDC, ADB, Serial and 25 pin D sockets. I’m hoping they might arrive today as they were last seen departing France this morning on their way from the US to UK. I’ll post an update once I have them and have confirmed they are the right parts. I’m pretty confident they will be though. All other parts in my mouser basket have already been fitted to my board so all good there.

Good luck with your refurb! (y)
Hi @craig1410,
The Mouser basket is really helpfull here!
Have you been able to fit Mouser (PDC, ADB, Serial and 25 pin D sockets) parts already?
 
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craig1410

Well-known member
@daanvdl yes, sort of. Let me take them one at a time as there are some issues to varying degrees.

ADB and Serial - No major issues other than the fact the holes on the PCB for the side support tabs are round and the tabs themselves are flat. This is a bit of a pain but no more so than if you extracted the connectors from the donor board. All I did was straighten out the tabs in the case of the ADB connectors, the Serial connector tabs were already straight. I then carefully thinned them using side cutters and some emery cloth until they would squeeze through the PCB holes.

25 pin D socket - Initially this looked perfect but after I soldered it in I went to install the 19 pin D socket which I sourced elsewhere and noticed that the 25 pin sits too far proud of the PCB edge. This might cause issues when fitting the rear cover because the socket flange will contact the cover before the fixing screw are fully seated. It might be possible to bend the pins and mounting tabs to allow it to sit more flush but I've not tried yet.

PDS - Unfortunately this is a press-fit type connector not a solder type so not ideal. The PCB holes are large enough to receive the pins but you need a special pressing tool to seat it correctly and finger pressure alone is not enough. Each pin is constructed with a little spring arrangement which is designed to provide some "give" when pressing the pin into the PCB holes so my plan is to take each pin out and use a pair of needle nosed pliers to pre-squeeze these springs to make them go in with much less pressure. Then I can just solder them as normal. I tried this on one pin so far and does seem to compress and stay compressed so make it easier to insert but I need to do this 119 more times without completely destroying a pin so wish me luck! I also need to look on mouser to see if there is a solder version of the socket which is in stock. Unfortunately the one I bought is described as "Termination Style: Solder Pin" but if you look at the data sheet it says "Toolless Pressfit" in the document title.

So all in all not ideal results...

I'll leave the mouser basket as it is just now but will take a look later to see if I can find an alternate PDS socket.

Edit: Actually mouser part 571-5535098-5 might be the one we need. It seems to be solder posts instead of press fit. I'll change the mouser basket to suit.
 

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robin-fo

Well-known member
Some more progress from my side: My board is ready to receive the final components which I expect to arrive tomorrow. I managed to reuse the RAM SIMMs, the PDS connector (!), the DB-19 connector (I do have replacements for this, but I considered the old one worth keeping), the serial ports (just for fun) and the CPU. I could also reuse the ROM SIMM socket, but it has suffered from the battery leakage and as new ones are due to arrive, I won‘t use it again (it‘s not soldered on the photo).
 

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PacificState

Active member
Firstly, thanks for doing this, Bolle!

I ordered some boards, and as others have reported, the SIMM sockets don't seem to fit. By playing around with Eagle, I'm wondering if a.) there *is* a standard SIMM footprint, but b.) the Eagle SIMM30 footprint is wrong. For one thing, there's no associated part number, and it also doesn't seem to match the measurements on the (random?) 30-pin AMP/TE datasheet I found for the 822056-2 socket (https://www.te.com/commerce/Documen...56KpdfEnglishENG_CD_822056_K.pdf822056-2), which I think matches the original logic board.

I've twiddled the footprint around in Eagle (the holes move to -/+ 1825, if I've got it right); I can attach the cloned library, but I'm not sure if there's a copyright question. Bolle, is it worth updating the gerbers?
 

craig1410

Well-known member
Further update on the 25 pin D and PDS connectors.

PDS - I've decided to bite the bullet and have ordered mouser part 571-5535098-5 which is hopefully the solder pin version of the press-fit connector I ordered last time. Will update to confirm once received.

25 pin D - It turns out there are two footprints for these and one of the key differences is the distance between the front flange of the connector and the first row of solder pins. This can be either ~8.1mm (actually 0.318") or 10.4mm. The latter is sometimes referred to as the European footprint and the former is the "MIL" footprint. What we need is the former.

When I ordered my 25 pin D connectors I ordered the Amphenol part number L77SDB25S1ACH4R but what I really needed was L77SDB25SA4CH4R. Note the 1A changing to A4 which is the bit that affects the spacing from flange to pins.

Note also the last 2 digits of the part number specify whether the connector has threaded screwlocks on either side of the connector or if they just have threaded inserts. These can also come in M3 size or 4-40 UNF. I'm not sure which thread size is needed but if the last digit is an "R" then you get a threaded insert and if it is "F" then you get a threaded screwlock.

mouser.co.uk are expecting some of these to arrive in early February but since I'm impatient I have ordered two of these and two of these which are in stock just now. I don't actually know what the difference is between the ones I've ordered but didn't want to have to go round this loop a third time! Again I'll report back once I can confirm if they are a good fit.

HTH
 

craig1410

Well-known member
Yes please (or just shoot it my way in a private message)
I’ll update the board with them - probably keeping both sets of mounting holes just in case.
I'm not sure there will be enough distance between the two different mounting holes to keep them from becoming a slot.

If not then I think I'd be inclined to adopt the mounting hole spec which @PacificState and I have found from the SIMM sockets we sourced. Especially since it also corresponds with two separate donor boards I have here. Unless of course anyone else has found that the current mounting holes fit either original SIMM sockets or sourced sockets.
 

NECyclone

Member
This thread is simply amazing. But, considering I have never done "any" soldering and certainly can't due to shaky hands (getting old sucks sometimes). What would it cost and is there anyone interested in making me a SE/30 board if I can provide a donor board? Is it doable for a few hundred dollars?
 

Trash80toHP_Mini

NIGHT STALKER
I'm not sure there will be enough distance between the two different mounting holes to keep them from becoming a slot.
I'd think any overlapping of the two holes would suffice in this case, assuming here that they'd be added to the laser cut list? Bumpage in a figure 8 pattern "slot" would be a help and a little dab'll do ya for cementing either connector in place? Roughing up or drilling out the exposed surface of either connector might yield superior stickum results?

I'd have to look for the discussion I had with @trag about the melt points of solder types, but here goes:

1) ROHS and real solder have a significant melting point differential.
2) the differential is enough to do a two stepped paste, place and bake assembly of SMT board components?
3) birdseed boards will come back set in ROHS puddles only, no?
4) if the melting point of real solder is lower than that of ROHS we'd be good to go for baking down the component side?
5) if the melting point of ROHS is less than that of real solder a workaround will be fun to noodle out!
6) what might a solder mask for component side add to the cost of a birdseed board run?
7) how might cost of both solder masks, birdseed and difficulty of assembly of a run of bare boards play out?

Will ChipQuick, with its low melting point, make an adequate permanent solder joint for folks capable of doing such a build? That might open up a third, pre-tin, place and bake process?

Developing a new formulation of solder by combining ChipQuick with real solder might allow more flexibility to stepped SMT assembly processes? Dunno if ChipQuick would play well with ROHS, but it's been around since long before that nightmare became reality.

The teamwork here has been an inspiration for me. Sometimes the inability to do what you folks are working out can be an asset? :oops:
 

craig1410

Well-known member
This thread is simply amazing. But, considering I have never done "any" soldering and certainly can't due to shaky hands (getting old sucks sometimes). What would it cost and is there anyone interested in making me a SE/30 board if I can provide a donor board? Is it doable for a few hundred dollars?
Hi, I'm UK based so probably can't offer any direct help but your question got me to thinking whether it would be economically viable to provide a board rebuild service and at what price it might break even. I think to a degree it will depend on how many donor parts are used, especially SIMM sockets and connectors, and also whether chip sockets are used even if only for the DIL chips and not the PLCC chips.

But by far I think it's the labour cost that would have greatest impact since it takes quite a number of hours to harvest the donor parts and clean them up ready for reuse. And then of course you need to solder all the parts onto the new board. I didn't keep a track of the hours I spent on mine, and actually it's still not finished, but I could definitely do it faster second time around. I still think it would take 5-6 hours to harvest the donor parts and then maybe 10-12 hours to assemble the new board. Then you'd probably need to spend an hour or so testing everything out and cleaning down the board.

So in total you're probably looking at 16-20 hours of solid work where the exact time will vary depending on decisions taken over whether to source new versus harvesting donor parts for things like connectors, sockets and even some of the chips (Serial Controller, VIAs and even maybe the CPU. Even at a very conservative £20/hour that would be £320-400 and at a more realistic hourly rate that would be a lot more. This is over and above the cost of PCBs and parts of course which I think would be at least £100 and maybe more with chip sockets everywhere and new connectors etc. I'm ignoring consumables like solder and flux and IPA although if using something like ChipQuik to remove chips, that stuff is very pricey but is probably worth it since it reduces time spent.

So there you go - I think you're talking around £500 (~US$680) much of which is labour but I'd be interested to hear what others think. If you were doing this regularly then certainly some savings could be made by ordering parts in larger volumes and experience will help to reduce time needed. But I think that's only going to knock 10-15% off the total at most.

I hope this helps to illustrate that this really is more of an expensive hobby than a commercially viable enterprise. Of course this forum has many members who are already very generous with their time and might offer to build your board for you for fun or for the price of a few beers. They may well also be more skilled than me or have better equipment which might reduce the labour required.

Best of luck!

ps. I think I should mention that the license provided by Bolle for the PCBs does NOT allow for commercial use so when I said above a "board rebuild service" I wasn't intending that to mean anything commercial. I would imagine that Bolle wouldn't have any objection to one forum member helping another member and providing help on a not-for-profit basis but that's not for me to say.
 
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Trash80toHP_Mini

NIGHT STALKER
This thread is simply amazing.
Ditto that!

. . . considering I have never done "any" soldering and certainly can't due to shaky hands (getting old sucks sometimes).
I've tried my hand at build and rework on and off for many years now. When young enough that my hands were rock steady, someone else was doing the soldering and rework whilst I did related things. Steadiness and dexterity has fallen off a bit, but no more so than vision. 20/10 has deteriorated to a corrected 20/15, dollar store readers and no driving restrictions as yet. The kids at work tend to go to the old guy with many and varied experience for help, so that's the nice side of putting some mileage behind you. ;)
 

Trash80toHP_Mini

NIGHT STALKER
I hope this helps to illustrate that this really is more of an expensive hobby than a commercially viable enterprise. Of course this forum has many members who are already very generous with their time and might offer to build your board for you for fun or for the price of a few beers. They may well also be more skilled than me or have better equipment which might reduce the labour required.
Indeed, could we but get together in the real world to share those beers, efforts and yarns.

Folks around this joint have been amazing from day one and of late those jumping into the hobby and development without, but with hopes of gaining requisite experience have been a wonder. Many development efforts have started here as school projects. Many folks seem to be easing into the hobby and development work here at later stages of life adding amazing, on point experience and know how to community efforts.

Many thanks to everyone here! :)
 
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