Flaky 128DCR

[Maraud]

I have a 128D which I was using with a lt. Kernal. Getting the LtK to work with the internal disk drive required cutting a pin on U3 and wiring to the daughter board. That was all well and good, but I decided to removed the LtK from the setup and when trying to resolder that pin (with a trace wire) to the board the damn thing broke off at the IC plastic.

Long story short, dead computer. So I pulled that chip, ordered a new 74LS08PC and put in a socket and all appeared well. Welp I'm still getting flaky behavior on file access (only in 128 mode) and I assume it's because the u3 chip is involved in burst mode and memory banking (who knows what else).

I'm gonna pull the machine and check my socket maybe the solder didn't float all the way through to the top of the board. Any other ideas?

 

[channelmaniac]

Look at the pins on the chip you removed... do you see coppery gunk stuck to the legs? If so, you pulled the plated thru hole out with the chip. This means the top and bottom layers of the board won't be soldered to the pin.

RJ

PS: A dremel tool with a grinding bit works wonders on fixing chips with broken legs.

 

[Maraud]

Look at the pins on the chip you removed... do you see coppery gunk stuck to the legs? If so, you pulled the plated thru hole out with the chip. This means the top and bottom layers of the board won't be soldered to the pin.

RJ

PS: A dremel tool with a grinding bit works wonders on fixing chips with broken legs.

yeah I got a very clean desolder - all the traces were still in tact and the holes were wide open (and old chip pins clean). My assumption is that in my caution to not overheat the board I didn't "sweat" (sorry, term I learn from soldering Copper pipes ie plumbing with my dad) the solder all the way to the top.... I'm MUCH better with an acetylene torch!