GenTenStation

The rest seems to be untouched. When I go to replace chips on my VIC 20 I will try to clean up this mess.. I just wish I had a picture of what it is supposed to look like.

@Nezgar @DrVenkman @BillC So all 3 of you suggested to try pulling chips and retesting. Doing this only got me to 4.26 V at most. So I was curious if maybe something was under the board itself (seen it happen in the PC world). To my horror I discovered an absolute MURDER of a solder job on the bottom. I'm talking dozens of scortch marks, scrapings and mountains of solder. So I think I found the short.

They're the only ones getting hot. The CPU seems to cycle with heat, which from another thread seems to be just what it does. From what I've read, you can run these machines without the BASIC chip inserted. So I'm hoping just an OS chip will fix it, since they're cheap. I'll try your idea and let you know what happens.

Would bad ICs cause this short? There are a few resistors by the power input that look like they have veeerrry dry solder joints. My knowledge on resistors is limited, so I'm not sure if that would be a place to look. Most of my circuit board work has been replacing ICs and caps up to this point.

I've recently joined the world of 8 bits with a 130XE and boxed 800XL. Included for 'free' was a non working 800XL. I've done the heat test and the OS and BASIC chips are absolutely roasting. So I understand they need to be replaced. My question is while my power supply outputs 3 perfect 5.00 volt pins, the voltage once it reaches the chips reads as 4.17. Is this low enough to cause the system to not function even after changing the chips? The power supply is definitely not the issue. It works great on the other 2 computers. I'd rather not open and probe the other 2 computers because they're like new and I'd hate to accidentally scratch or crack the aging plastic. The goal is to get this third one working as the one I actually use so the others can remain in great aesthetic condition. Thanks for any help you all can provide!