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Thanks! I figured I would look at both the SWIM and SCSI packages. Which controller do you mean - the Video one ? I also see another Sony brand SRAM close by and I assume that's the VRAM. Will also look at that. I'm not giving up on it yet :-)

Went back over any suspect joints and one step passed, no more Sad Mac error or chime.    Now getting pointer in top left but no flashing question mark and my SCSI2HD external doesn’t show any signs of access nor does floppyemu. The striped display changes and clears. Looked for hotspots on...

New RAM finally made it through the quagmire of postal parcels, soldered on and now getting Sad Mac straight away data bus or RAM.  Not sure how to decode the minor error. I’ll go back and recheck my work, here’s the code in case someone has a eureka moment 

Acquired a Techstep kit virtually unused (cables still sealed) but the display was foggy dark so the seller cut me a deal. Took it apart after researching vinegar syndrome and the sniff test confirmed my expectations.    Removed the old film which looks like bad sun tint and replacement film...

I thought more about this and as I don't ultrasonic for more than 2 minutes per side and at the recommended 60C I wouldn't have expected the thermal expansion to be that big but I follow the soak up with the warm oven at 170 for 30 minutes after the post IPA wash. That seems a more likely target...

I came across someone on the FB 68K group who mentioned they ran into the same RAM Sad Mac code after recapping when before there was no issue. The only other common link appears to be the soaking/cleaning of the boards, which may have been a good idea in theory but in practice kicked us in the...

i figure having some brand new ones doesn’t hurt...

Pulled the chips off the board and some of them give inconsistent test results on my TL866 so I ordered a few new ones to be safe. While I had the board cleared down, I thought I would ask if anybody more versed in the backlight trick can see anything here which may warrant more investigation...?

Okay got the RAM test working on my programmer and a socket to fit the chips so I guess time to pull all the onboard memory and validate it. Hopefully it shows a bad chip or two which might solve the problem 

The notched side is on the right so that would be pin 14 though  Interesting note on the diagnostic mode makes sense as a way of emulating the Techstep. 

So I thought I would take another look with the flashlight under the pcb trick around that 74AC244 alaska360 pointed to (U13C) and thought I might have struck lucky with this I ran a through wire to the other side but hasn't changed the Sad Mac start. But looking at the schematic I didn't see...

So, does that suggest I might be able to run the MTP Emergency floppy on my Color Classicand connect to the Portable mobo ? Worth a try...

I'm not dissing the techstep in these days of "vintage" hardware - just back in the day when you could still get a replacement logic board from Apple you could just throw parts at it ;-) I guess we wait to see if @mg.man gets his SE to talk to the Portable....

Interesting - seems wildly un statistical that three suffered RAM Sad Macs after a recapping....did you do any board soak/clean as well ? In the absence of any other obvious path I'm going to pull the onboard RAM, test each chip and see if there are any duds. Nobody seems to be able to point to...

This was in the days before the Internet - a subscription meant you got an envelope of CD every month as long as you kept paying Apple $$$$ I think we had the TechStep on trial for evaluation and we didn't end up keeping it. The main advantage to keeping it was that if it reported a component...

I think I found it https://macintoshgarden.org/apps/apple-mactest-pro i remember the standalone box from my distant past working in AASP in UK. I don’t recall us being hugely impressed as it was a pass/fail device which meant swap the motherboard out service exchange with Apple, no board level...

It's like adopting senior cats or dogs, we don't know their history, we hope they don't destroy the furniture and pee on the floor and can get a quality of life in their later years :-)

I think it's time to put a bigger hard drive in the CC, half my 80MB is full and I haven't got the elbow room to upgrade to 7.5.5 from 7.1 which leads to the "anybody using floppyEMU with CC" question ? It seems I could put the new HD in and use the installers on floppyEMU to boot up the machine...

Well maybe it really is a bad RAM issue - replaced all three of the 244s and looked over the traces under the chips while there and all looked good and seemed to buzz out okay. As I said, there was no apparent cap or battery corrosion on this board but I don't know the history of the machine so...

I pulled that chip and didn't see anything untoward but I guess I need to buzz out each pad to its destination. I have a few new '244 and I mentioned I had already replaced the 157/10/02. In other news, my Color Classic lives again and the fluttering sound of Flying Toasters can be heard once...