Mitchell Spector wrote:
It is a user moded board (not by me, another Apple II user did it). From what I recall he cut the bridges between the SRAM sockets,and in-between, soldered in single socket row strips so it can make use of either wide or narrow cache chips. He installed narrow chips (rated 15 ns) for TAG, and wide chips (rated 45 ns) for DATA.A full-sized oscillator socket was soldered in, as well as a socket for the chip at U8 (which had a 74HCT00E plugged in) with the other chip next to it left as is. A standard WDC 14 MHz CPU was installed, with a tin oscillator which was tightly zip-tied down.
Based on this, I think you are right and there might be a weak or faulty solder connection. One possibility would be the zip-tie putting pressure on the oscillator, it's socket, the PCB or all three. Heat, applied through current and convection may have caused this possible fault to expand. It's also possible this was part of the earlier occasional failures you mentioned.
You can test the socket if you have the tools. Alternately, you can jury-rig a simple light circuit to ensure the socket and soldered connections are intact.
If it is the oscillator socket, then a simple resoldering is all that
would be needed. Unfortunately since I don't own a solder pen
and have _zero_ experience with one (I'm not about to practice
on my ZipGS heh) I'm no better off. :(
The fix may not be all that difficult but would be dependent on the original setup. You should be able to get a soldering iron at reasonable prices. In the US one can go to Radio Shack and pick these up pretty cheap. While you're there get some flux and solder then practice on some old junk or wire until you feel comfortable.
I'm not all that great at soldering myself, but it's not that hard. One small tip, less is more when it comes to applying solder to the connections.
Cheers, Mike T.