Macintosh SE/30 M5119 - Year long troubleshooting battle

Thanks for that! That's extremely helpful for the situation I'm in. I'll stop worrying that Y3 is a problem, or that is was partially rotted being so close to the UE10 that was damaged.

I took your advice and found a mostly working SE/30 for $375 on ebay, only the SCSI HD/chip/traces are having trouble, it does boot from floppy and has a functioning CPU/board/RAM/ROM, with the Sony CR-44 PSU in it - from looking at the IEC connector in the rear - so it should be a close match to my current one.

I've had some interesting clock signals from the CPU 'walk the bus' test, compared to the Simasima Repair Guide:


Looking forward to comparing signals with the new-to-me SE/30 that's on the way here.

Tried my new TechStep today and it's as I expected, unable to communicate with the SCSI/Serial ports. I have two nice SE's here I can test it with until the new one arrives.

Thanks again @muse!

Decided to press on with the repair guide until my test SE/30 gets here.

In the Video Multiplexing section on page 50, UD8 is missing signals and has distorted wave forms, it doesn't look damaged but who knows if there's electrolytic fluid under there still. UE8 has already been replaced and the signals are present.

Going to replace UD8 with 595-SN74F253DRG4, getting (4) just in case: https://www.mouser.com/ProductDetail/Texas-Instruments/SN74F253DRG4

Also the Video ROM at UK6 is missing many signals, going to get a 556-AT28C64B15PU, just in case: https://www.mouser.com/ProductDetail/Microchip-Technology/AT28C64B-15PU

Already have a TL866 programmer, but can anyone tell me where to get the video ROM binary from for UK6?

After watching this video on how to read the Mac SE/30 UK6 Video ROM chip:

I was able to do the same with my less expensive TL866-3G:




Had to select the AMD AM2764A chip in the Xgpro 13.06 software, and disable the Options to Pin Detect and Check ID - was then able to Read the ROM.

This tells me there was nothing wrong with my UK6 Video ROM chip. The missing signals at UK6 are hopefully due to the UD8 being bad on this board.

After looking at UD8 for a while with the scope, I've absolutely determined that the signals A0 at pin 4 and A1 at pin 12 are entirely missing, all the other signals at UD8 are present and correct.

I have verified the missing A0 and A1 at UE10 ASC, UK6 the Video Rom and also UI8 the Glue Chip. I have (4) F253 chips on the way here Tuesday of next week, looking forward to replacing UD8.

Regarding my sound being all but gone besides the startup pops and clicks, it's looking like TL071, or Q1/Q2 may be bad, they have corrosion on them fairly badly. Going to order replacements for those once I've done some more troubleshooting with a working reference SE/30 logic board that is set to arrive tomorrow.

Enjoying this fight and won't be giving up until I have (2) completely functional SE/30's.

Got SE/30 #2 today, did alright.





The logic board gets all screen lines and has the flashing ?, even though the LB is entirely missing C12, one of the leaky 47µF caps and also the small C6 1µF leaky cap - no sound as a result. Was told it won't boot from HDD either but haven't tested it yet. Came with 8Mb of RAM.

Ordered all the caps for the PSU, AB and 800K floppy, thanks to @JDW and his YT videos for the Mouser cart for those. Went with Polymer caps for the LB this time, instead of tantalum, all except for C6 the little 1µF tantalum cap.

I have (2) nice SE's also, one entirely recapped and one completely stock, those and my original SE/30 all have the National Electronics CRT in them, this one has a Samsung:


Flyback transformer looks to be in good shape also.


The new-to-me SE/30 smelled like a damp basement, got it all scrubbed up and smelling like Dawn soap. The disks it came with are broken sets of OS 7.1 and 7.5, each missing one or more of the disks in the set; even came with a CD of System 7.5. Pulled back the slide cover on some of the floppies and only some of them may have mold, they all smell moist though.

Came with a grimy KB and mouse that will get cleaned tomorrow.


As a result of the new LB missing caps, I'm not going to use it for reference signal testing until it has been recapped.

The new UD8 chip will be here Monday, for #1's no sound and no logic.

Update on SE/30 #1: New UD8 installed, problems remain. I have continuity and solid board traces everywhere but am now suspecting an IC/chip failure - somewhere.

With the new SE/30 #2 components, I was able to verify 100% that my ROM and RAM are good. The strange thing is all of my wave forms in the ROM slot are good from A2-A31 but as soon as I insert the ROM SIMM in the slot, the working signals disappear at UD8 and UK8, specifically UD8 Pin 3, 4, 9, and 12. Another odd symptom is my Reset S1 works perfectly as verified with a meter, but I'll need to push it a few times to get the square waves in the ROM slot to appear. S2 NMI switch does also affect the wave forms without a ROM in the slot. Will keep at it.

UD8 - not pretty but bridge free and connected, matches UE8 now .



SE/30 #2: Hooked it up to the new TechStep and it passes all tests! I had to enable Termination to get the TechStep to connect to the logic board, but the only thing it recognizes as a problem is the Sound, for which I'm still missing C12 and C6. Have a full recap kit coming for PSU, AB and LB; #2 should be an easy fix. Looking forward to using it as a reference to fix #1.

Received all of the new caps for SE/30 #2 today, recapped the LB.







The Sound test passes and I do get a clean chime and sad mac but trying to run the Mac SE Tour floppy produces clicks and pops, not smooth sound.

Floppy loads, but no BlueSCSI image, or HDD boot. Will go through the SCSI chip tonight to make sure all traces are present.

Have some Elma TEC Clean A1 arriving tomorrow, hoping an ultrasonic bath will make a difference.

Turns out my image I made of System 7.5.5 was no good for BlueSCSI. Tried a pre-built image of 6.0.8 in my SE with BlueSCSI and it worked, plugged 6.0.8 in to SE/30 #2 and it booted up so fast. Stoked!


TechStep kept saying everything was fine with the SCSI system, I was even able to connect the stock HDD to TechStep and it verified it was a Connor 40Mb, but I kept getting this error with the Connor.



Made me think it was my UI12 NCR SCSI chip this entire time.

Looks like I have a working reference board to pull signals from in order to fix SE/30 #1. Will go over the sound crackle/pop with the SE Tour floppy again - but the chime and sad mac tones are pristine on SE/30 #2.

I really needed this one win, it's been over a year now of defeat at every step with SE/30 #1. Still having fun though


EDIT: Turns out the System 7.5.5 image was good, it was my naming convention that caused it not to load. It might have been spaces or the underscore that caused the issue, named it: HD0-System-7.5.5-2048M.hda - and it now works.


Huge thanks to @Ron's Computer Videos for the method I used to create this image.

Got through the recap of SE/30 #2's PSU and Analog Board today, will hot glue the caps when the new Noctua fan arrives:



The fan will be here Sunday and this can go back together. The brightness knob has a sun spot on it, will treat it at the same time as the case and mouse/KB, with 12% peroxide creme and a 10W UV light in a box - had great results with this in the past.


That makes the third Sony CR-44 PSU and SE-SE/30 analog board I was able to recap as a direct result of these two videos:


Need to order another floppy eject gear from ebay, (4) of them cost nearly the same as (1) does, might as well stock up: https://www.ebay.com/itm/235320197466

This next floppy will be the fourth 800K floppy restoration, thanks to this video:

Got the ultrasonic detergent today, for the price, was not expecting this bottle to be this small; good thing not much is required per 10L ultrasonic bath.


Will clean SE/30 #1 Logic Board tomorrow, outdoors, in case the smell is toxic.

Thanks to JDW once again for his excellent videos, he just saved me from myself by noting at the end of the video below, that the 1.44Mb has (2) different caps than the 800K SE floppy's. I had ordered the caps for an 800K drive, it had been a while and I forgot that SE/30 #2 came with MFD-75W-01G, the 1.44Mb 'Superdrive'.

I still have Molykote EM30L from SE/30 #1's 1.44Mb drive. Just need to order the (2) correct caps now. Thanks again!