URC-6131n JP1 Soldering

ti83programmer · Post by **ti83programmer** » Wed Mar 01, 2006 2:41 am

I have a newly-acquired URC-6131n(w) remote that I'm trying to add JP1 to.

I soldered in the 6-pin JP1 header, and because I bought the wrong 24LC16 EEPROM (mentioned in a previous thread, where the conclusion was that if I could make it fit, it might work). I ran 5 wires from the PCB (pins 5-8, and a wire for pins 1-4), connected wires 5-8 appropriately to the EEPROM and the last wire across all of pins 1-4.

I did the 981 reset and I got two blinks, then two more blinks, so I'm pretty sure that means the EEPROM worked (yay!).

But when I hooked it up to the PC, I get "No response from remote" in IR. Immediately after that, I get two blinks from the remote as if it succeeded.

I can power the remote from the JP1 cable (still freaks me out that it can do that).

I'm kind of at a loss here on what to try next. I checked the JP1 cable with my 6012 and 8811 and it up/downloaded just fine. Any suggestions?

ti83programmer · Post by **ti83programmer** » Wed Mar 01, 2006 3:09 am

Chalk it up to bad soldering, I guess, because it works great now. Thanks for putting up with me!

I'm not sure anyone's tried to solder the big chip in before, but now we can say it's been done.

Post by **The Robman** » Wed Mar 01, 2006 7:21 am

From the description in your first post, I would say the bad soldering was probably on the 6-pin rather than the EEPROM.

ti83programmer · Post by **ti83programmer** » Wed Mar 01, 2006 9:31 pm

Yeah, that's what it was. Somehow one of the pins on the 6-pin header came loose and was being pushed out when the JP1 cable was inserted. But it's fixed now.

Post by **The Robman** » Wed Mar 01, 2006 10:20 pm

If the pin worked loose, I'm guessing that you didn't use flux. I'm a big fan of flux as it makes soldering so much easier.

ti83programmer · Post by **ti83programmer** » Wed Mar 01, 2006 10:27 pm

Nope...never used flux. I'm curious, though. I'll have look into it.

Post by **The Robman** » Wed Mar 01, 2006 10:32 pm

When you don't use flux, it's very difficult to get the solder to actually run down the pins and bond with the pads on the PCB. It tends to form a ball shape whereas it should look like a Hershey's Kiss.

If you puts some flux down on the pads first and then do the soldering, you'll have no trouble getting the flux to run down into a Kiss shape.

Now, I'm sure that a true soldering expert would have no need for flux, but I'm just a hack so I use it all the time.

The stuff that I use comes from Radio Shack, the part # is 64-021 and it's in a tube. I just looked on their site and they don't appear to sell that tube anymore. The closest I could find was part # 64-022 which is the same stuff in a tin.

ti83programmer · Post by **ti83programmer** » Fri Mar 03, 2006 6:20 pm

I'm by no means a soldering expert, but somehow I managed to get it on this one remote.

I'll keep an eye out for that stuff, though. Good tip, thanks.

Post by **The Robman** » Fri Mar 03, 2006 9:52 pm

I used to manage also, but sometimes it was really difficult to get the solder to bond with the pads, but with flux it's easy.

In the early days of JP1, I had several people send me broken remotes for spare parts where they had trashed the remote trying to solder in the 6-pin, presumably from over heating the pads.

jherrick · Post by **jherrick** » Sun Mar 12, 2006 9:32 pm

The Robman wrote:Now, I'm sure that a true soldering expert would have no need for flux, but I'm just a hack so I use it all the time.

Rob,
I don't know about that. I consider myself pretty good; I'm certified and can solder some pretty small stuff very well, and I still don't even try without flux. My favorite is the Kester No-clean #951. Comes in a pen and won't turn corrosive or conductive after long times. Plus it's not real sticky and doesn't need to be removed (hence the "No-clean").
I also try to use flux-core solder when I can, as that also helps the "wetting" (which, to those who don't know, is what Rob was referring to when he mentioned the solder running down the pin and forming a hershey's kiss shape, not a ball).