On 09/20/2020 4:43 PM tgerbic <tgerbic@gmail.com> wrote:


Roger,

The PDF schematic is a bit hard to read but you are right they are S types which, based on a 74S112 datasheet, four Clock inputs could pull 4ma each worst case for 16ma total. I think the oscillator can drive up to about 20ma. Good suggestion to move to HCT.

Ray,
I have a couple of old electrical cutters (1970s era) that have a fine point and great for cutting IC pins. I also use this method of rework from the top of the board on chips and axial leaded components. Some products are a nightmare to get a board out to desolder/rework from the bottom. Sometimes you can cause a lot more problems with the device by trying to take everything apart. Can be hard to install sockets unless you install something like a machined single row WW-pin type connector with the leads shortened but it can be done.

Regards