I'm super happy to report that my 102 is back in action! https://twitter.com/48kRAM/status/868911016884801536
Thanks to Steve for pointing out a cheap parts supplier. The chips arrived on Friday. They did appear to be pulls (based on some gunk underneath one of them) but they were cheap and they worked. I watched about half a dozen youtube videos on replacing SOIC chips. Most of them presented the "blob a pad and slide the chip into it while hot" method, so I went with that. Using my dad's hot-air station, I pulled a few SOIC-14 parts off an old DSL modem and practiced replacing them. Once I was confident, I cleaned up the 102 board, layed down plenty of paste flux, and tacked the "new" chip on there. It was actually pretty easy - easier than the modem, probably due to slightly larger pads. I used a small chisel tip on a Hakko 936 with 60/40 rosin-core. I'm pretty happy with th results. Needless to say, I was pretty nervous about turning the thing on, but I was elated when that number came up on the screen. Anyway, thanks for everyone's help on this repair. Your input is highly appreciated. Also, I now have 2 100/102 RAM chips, and several 139's that I don't need. If anybody needs a RAM chip, I'll drop it in the mail for shipping cost. Thanks again! -Josh On Thu, May 11, 2017 at 6:18 PM, John Gardner <[email protected]> wrote: > Get some cheap IC adapter boards, DIP to SOIC for instance, > > & practice soldering duff chips to them. You'll get the hang of > > it without the stress of losing parts looming over you. > > The adapter boards will come in handy too, by & by... :) > > On 5/11/17, Josh Malone <[email protected]> wrote: > > On Tue, May 9, 2017 at 6:10 PM, Stephen Adolph <[email protected]> > > wrote: > > > >> Josh, > >> I think you can use a 75HC part in this application. even 74AHC I > >> think. you don't need to go back to 40H. way cheaper. > >> ..Steve > >> > >> http://www.ebay.com/itm/5PCS-74HC139A-Encapsulation-SOP-16- > >> /381651800874?hash=item58dc38532a:g:mQ0AAOSwNsdXSUyd > >> > >> something like this. not sure if that is the right package.. my > >> point is..ebay is cheap. > >> > >> > > Thanks for this. I haven't yet started my brain down the rabbit hole of > > part substitution lookups. I think the package is right - SOP-16. I think > > I'm just going to go ahead and order this part you linked. Completely > worth > > the gamble in terms of $$. I really just hope I get it soldered on the > > board. > > > > -Josh > > >
