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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...

Stumbled upon this on ebay, remembered your post. Looks like a complete kit. https://www.ebay.com/itm/176800942441

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...

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...

It's pretty much vital to have multiple units to test with, it would seem, in order to determine quickly what the issue could be. Is the bad fly-back covered in black soot, like it was heavily used over the years?

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...

You were able to fix the problem, or you just found the problem so far?

Thanks for this! Setting the probe to 10X made the leg farthest from UE10 - which corresponds to Pin 25 of UE10 - produce a good wave form again, even with the extended green ground lead: 10X probe setting on the probe itself, and connected to UE10 Pin 25: But 10x probe setting on Pin 24...

Thanks so much for your help, I really appreciate it! I'll follow any directions Will may have, or tests that need to be performed to get this board running again. I think Y3 is good but would really like to rule it out as a problem.

I made the shortest ground I could. Stuck it in the main power connector ground: Wave form is about the same as the long green extension, somehow: But the Y3 leg that is farthest from UE10, that had the cleanest wave form yesterday, doesn't show anything with the short ground: Look what...

Put in some time today going through the CPU walking the bus tests. I'm now getting all of the square waves that should be found between A2 and A22, but I'm seeing the speed values are different than what's expected. A2 - A7 seem to be off by a line, A8 - A18 seem to be off by two lines. I...

I have been working with the Simasima Repair Guide for about three days now, I'll post some things I found, approaching it from a new users perspective in a moment. I definitely watched the video you posted regarding the shortest ground probe lead possible, and I got a bit confused by the...

I shortened my probe ground lead, or got rid of the extension I was using - this green one: And used only the ground lead the probe came with: This made the ringing less on the closest Y3 leg to UE10, which was the really odd pattern before: But now the Y3 leg farthest from UE10 isn't...

I was using a very long ground lead, I'll make it as short as possible and measure again at Y3, UE10 and C33 and C34, to make certain of what I'm seeing here. I'll do this now. Thanks for the reply!

I feel like I keep repeating myself, because I've replied to two different forums, and many threads trying to narrow down where the problem is coming from. A working SE/30 board is hard to come by these days, I'd have to buy a $500+ working SE/30 to get an example to follow. The immediate and...

Wondering if my Y3 has been damaged from a leaking cap. My UE10 had four traces severed, I had to remove UE10 and reinstall it to fix the traces. My Y3 issue looks like this: Leg farthest from UE10: Leg closest to UE10: Should both legs of Y3 be identical in wave form, like Y1 is? No...

Thanks for the detailed explanation. The UB11 Pin6 issue was confusing me greatly, it was the last unknown for the Reset troubleshooting section, that could've still be responsible for the missing square waves from the CPU bus. I should have the new MC68030RC33B next Monday.

So when the Repair guide says Pin6 should be 0V, this is an error in the guide?

S1 is perfect everywhere else and throughout the Simasima Repair Guide, everything works except the Sony Sound chips Pin6. Just so there is no confusion I made this video: Pin5 is 0 - 0.80mV Pin6 never goes much below 3.9, for both UB10 and UB11. Thanks for the help!

This guide was the reason I found this site and joined, well done and thank you for this! I wanted to ask about the Reset section, on page 44, it instructs that UB11 Pin6 should go to 0V. The picture is showing UB10 highlighted on my logic board, instead of UB11 - I can't get UB10 or UB11 Pin6...