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Looks like TL071 and Q2 are also rotted. What's TL071 and Q2 responsible for? Looking for them on the schematic now.

Pin 22 is also broken. This has to be done, might as well be now.

Thanks! I'm getting ready to check every pad and via connected to UE10, on both sides of the board, right now.

The three missing pins are 19, 20, and 35. Pin 35 is Vcc for UE10, and it was rotted off like UE8 was. Need to manage my expectations, but this feels like I'm on to something significant here.

As soon as the hot air flowed, the kapton tape lifted, and then the foil got in the way. Removed the kapton tape and foil, used the square nozzle for the hot air, flooded UE10 with flux, and set the Yihua 959D to 400°C, with a fan speed of 7. Took about 2 minutes and kept bumping it with...

Taped off UE10. Working up the courage to do this, now that things are in order.

Got the new scope, might take some getting used to, there's a disconnect between the eyes and hands having the screen remote - just feels weird at the moment. Looks incredible though, now that I can see what I'm doing. Will practice getting my hands and eyes to agree on this, and then remove...

Instead of going with a desk mounted AmPro for $600+, I'm trying a $139 Amazon one, it should be here in the next couple of hours, with same day delivery. https://www.amazon.com/Andonstar-AD246S-M-Microscope-Biological-Compatible/dp/B09VPPS96M

Thanks! I do have the standard Yihua 959D. But UE10 is surrounded by those new tantalum caps. I do have kapton tape and foil. If I'm going to remove UE10, I really need better magnification, and it doesn't come cheap. Might have to wait until I can fix that.

I was thinking that too, but removing that entire chip feels like serious business. Is the VLSI chip impossible to find an NOS replacement for? Can that be socketed? Good to know. If you look at Post #74, above, you can see the traces have changed to an amber color immediately following the...

Learned that UV light can sunburn a PCB, this one upset me pretty good, had to walk away from this for a bit. Broke the leg off the the replacement LS166, and had to order a new one, and clean the old one off, and start over. It's not pretty, but it's connected to where it should be on both...

Can't tell if this is dry, exactly, but after 30 minutes under the UV, I'm wondering if it can get any better. Might give it another 30 minutes under the UV, to see if anything changes.

About to mount the new UE8 chip. But first had to clean up the scraping of the board. Did find copper under there, but below the top layer. Not good. UV solder mask not yet cured. May have made it too thick to dry properly. Should know soon.

Thanks for that! The LS166 should be here Saturday, I'll get those traces checked.

That's a good call @obsolete , that does look to be touching a pin on the VLSI chip, @BespokeMan

Yes, noticed there was a substitute still available, and deleted that edit.

Do you get the chime at least? I used the zoom feature on my ancient phone, to take those close up pics of the UE8 chip. Can you get some good pics of your row of Uxx chips, that UE8 is in? You're welcome to post some pics in here, if you feel like it. The new LS166 UE8 8-bit shift register...

Looks like the bodges won't be difficult to get connected again. The red line is GND, and can be patched in to the via above it, tested and proven. The green bodge doesn't have far to go either. Will get the parts ordered and get back to this soon.

You're absolutely correct, those pads were burned off, before I started digging at the board looking for copper under there. Should've left it like this: But I watched a YT video where the guy explains you just need to scrape away that black layer to get to the copper below. Well, not if the...

Is 30 AWG Kynar wire sufficient, or what would you recommmend?