So here we have an hp 10BII Business calculator that shows symptoms of a bad ribbon cable

To start with this repair we're going to need a few tools.
1. Small flat head screw driver which will be our multi-tool through this.
2. Small gauge wire which was taken from an ethernet cable.
3. lead free solder preferably the kind with 2% silver.
4. finger nail clippers of scissors.
5. Needle or a tooth pick.
5. No clean solder flux paste.
6. Some kind of conductive paint/resin.

Heres a look at the back with the battery cover off. Note there are 4 little holes which will need to be drilled out. I used the flat head screw driver on this like a drill and it works nicely.

This is what it looks like after they are drilled out with the flat head.

Now we can move on to removing all the clips from the inside of the case, again our flat head multi tool will come to the rescue by being our pry tool. There really isnt anything to damage so dont be afraid to get in there.

Now that we have it open here's a look at the beautiful black pcb board and internals. It's a shame we don't get to see the processor due to the black resin.

Our next step now will simply be to remove the ribbon cable. This is done just like a sticker it simply peels off.

Now we need to clean up the tape that's left behind from removing the ribbon cable. As you can see very faintly on the back of the lcd, This is etched conductive glass. There are no solder pads like we have on the main board that is what makes this repair much more difficult then that of the ti-83 and its counterparts.

Our next step now is to Apply some flux and tin the solder pads on the motherboard.

This next step i simply put some hot glue around the edges of the motherboard and lcd to keep everything in place and from moving around. The case still fits perfectly back together even with this glue here.

The next step is for us to solder in our leads. This is possible the most paint staking part of this whole process. We use our finger clippers at this point to cut each lead as it is soldered.

In this next step we're going to again use our flat head multi tool and bend each lead down to the lcd screen in an L shape to allow us to continue on to the next step.

At this point we're going to take our needle or our toothpick and electric paint or other conductive resin and place a small amount on each lead. don't worry about cross talk when the glue drys you will be able to remove some and get rid of it, it is also so low voltage it will not hurt anything if you power it on while something is shorted.

We now wait 5-30 minutes depending on your manufacturers instructions. Also do not use any heat source to cure these conductive glues faster. They will crack and this whole repair will be botched. We now can put the back case back on. It may take a little force to get the feet to fit back through the holes but they will go in. Also a little dab of hot glue will keep them in place, as they were plastic rivets before holding it.

And Voila there you have it a fully functioning DIY repaired hp 10BII financial calculator. I hope you guys enjoyed this. It is my first guide if you would like to see anymore just let me know and i will see what i can do.

Impressive repair job, especially with the conductive pads on the glass! Was this done in one go, or did you have to redo certain steps?

All-in-all, congrats on having a working calc now!
I purchased 40 of these calculators for 50 dollars off the fleabay, and i figured i would keep a few to put in my collection and a few to resell online. This was the 3rd one i attempted before finding a solid process that worked perfectly. My mistake on the first 2 was i had used a precision heat gun at 225 degrees to cure the glue faster which caused it to crack and I had already put hot glue on the wires which made it almost impossible to try and repair again. I looked up on the manufacturers website about the cure time for this specific glue and they also indicated that too high heat will crack the conductive paint.
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