Marchintosh Project - SE/30 Reloaded

[joethezombie]

For #Marchintosh, I'm forcing myself the time to finally complete the long waiting SE/30 Reloaded board from @This Does Not Compute's group buy campaign. In my defense, it has taken quite a bit of time in discovery and shipping to obtain as many NOS parts I could find.

Instead of fitting parts bit-by-bit and testing as I go, I took the dangerous approach and spent several hours this morning populating the entire board with all the parts I sourced from several suppliers. I even found the dual-SIMM ram sockets Apple used with metal locking tabs. I built this board to assist with repairs-- it will be used as a test bed for checking chips pulled from other boards to reduce de/re-soldering cycles, so I wanted as many sockets as possible.

I currently have a non-booting board with a garbage screen, but I do get a speaker pop, so that's seems like a good sign. After dinner I'll do some signal tracing with the oscilloscope and check reset, clocks, and the different busses for activity. A quick check with the multimeter didn't show any dead shorts, and the voltages seemed correct. I'll update this thread as my troubleshooting progresses.

 

[Bolle]

Check if you've got BAS40-04 instead of BAS40-06 diodes installed on the bottom of the board for D4 to D19.

 

[This Does Not Compute]

I currently have a non-booting board with a garbage screen, but I do get a speaker pop, so that's seems like a good sign. After dinner I'll do some signal tracing with the oscilloscope and check reset, clocks, and the different busses for activity. A quick check with the multimeter didn't show any dead shorts, and the voltages seemed correct. I'll update this thread as my troubleshooting progresses.

As Bolle mentioned, check the diodes on the bottom side -- I sent an email to everyone in the group buy a couple weeks ago about the wrong ones being populated, and mailed out the correct replacements early last week.

 

[Bolle]

I sent an email to everyone in the group buy a couple weeks ago about the wrong ones being populated

Ha, alright. I wondered if the word on the JLC blooper already was spread or not because I didn't find anything in one of the group buy threads yet.
Good to know everyone is informed already

I'm still kind of curious if it's all boards that they messed up.

 

[This Does Not Compute]

I'm still kind of curious if it's all boards that they messed up.

I think it's fair to conclude that they loaded the wrong reel on the pick-and-place for that part -- so unless they used up a partial reel and swapped them mid-run, I'm pretty sure all the boards are affected. I'm just glad it was a simple, easy-to-replace, inexpensive one. (Could you imagine if they did something like install a PLCC socket rotated 90 degrees?)

 

[joethezombie]

Well you guys ruined all the fun.

A fast check with the multimeter showed inverted diode on pin 1 of those dual schottkys. A quick run with the hot air to remove the old and flow in some I took off the original board was all that was needed. The board sprang to life, and I'm running iterations on Snooper error free!

I guess I should check my vanity account every now and then, I didn't know anything about the reel mix-up, and I haven't yet received any replacement parts. They'll go in the parts bin when they arrive.

Thanks @Bolle for the board re-creation; as always, absolutely incredible work! I think I've said that so many times that it's getting creepy!

And thank you very much @This Does Not Compute, because I would never have had the time to put an order together with all the parts and madness that comes with a pre-populated board, and taking care of any issues up to the very end. Very well done!

 

[croissantking]

they loaded the wrong reel on the pick-and-place for that part

Oh man, this is really disappointing to hear after all the other difficulties of the group order. Glad it’s been diagnosed though.

 

[joethezombie]

I’ve had some questions, if I have video corruption requiring the bodge. Yes, I did have corruption and it was fixed just as Bolle and Colin recommended.

Other than that, the board has been running error free! I soldered in the PDS connector and will be testing with some expansion cards over the weekend.

Here’s a photo of the bodge I did. You also have to cut the trace going to that pin.

 

[joethezombie]

I have built my second board! I received the replacement diodes from Colin, which I flowed onto the board. I also used a set of the Bourns Again parts he sent along with the group buy:



Works great with the replacement parts, no issues so far. One thing I will mention. Be aware if you installed a socket on your board for the 68030-- if you try to salvage a soldered processor from your battery eaten board, there are four pins (one in each corner) that have a standoff. This will prevent the processor from inserting into the socket all the way and it will remain loose. I ended up not using it because of this and instead used the standard gold topped version. Not an issue if you are soldering it directly to the board.