TI-85 Accelerate Troubleshooting

Soldering

Be careful not to burn up C9 (it is a very small SMD) or any other part of the calculator. Use a pencil soldering iron (15-30W) and don't touch the parts longer than 4 seconds.

Make sure you don't have a short circuit somewhere (soldering tin or small pieces of cut wires)

Implementing a switch or variable capacitor

It is important that you use proper tools, otherwise you may damage the back of the calculator. I suggest to first take off the back and cut out the whole, secure the switch or var cap with glue and then solder the wires.
Be sure you choose the right position of the switch or var cap (and the right size of it) so it doesn't damage the interior of the calculator.

Just removing the capacitor

I don't recommend this but several people have done it, its definitely the easiest solution. However, keep your old C9, just in case... and DON'T bridge the contacts, just remove the capacitor and close the case again, that's all.

Why is my TI-85 not as fast as I expected

If you have implemented a variable capacitor or a switch, make sure that all your wires are as short as possible otherwise your calculator won't be as fast as it could be. Use new batteries. Rechargeable batteries are good for the environment but bad for the speed since their voltage is only 1.2V not 1.5V
However there are some rechargeable batteries e.g: Rayovac Renewals which have a voltage of 1.5V, they are the best choice.

What can I do when my calculator turns on with a few rows of black lines or nothing

First check for short cuts and make sure the wires are isolated properly. Set the display contrast to maximum. Make sure you use new batteries. If this doesn't work, try this:

Remove all batteries (backup battery included), press "ON" about ten times and wait a few minutes. Put the batteries back in and try to start the calculator again.

If this doesn't work, try this: Take out all batteries (backup battery too) and make a short circuit: connect P1 and P4 with a wire and wait a few seconds, remove the wire, put the batteries back in and turn the calculator on again.

--------------------------------------------------
|
| 
|  ~~~~~~~~~~~~~~~~~~~~~
|  ~ P                 ~
|  ~ 1                 ~
|  ~ ----------------- ~
|  ~ P                 ~
|  ~ 2                 ~
|  ~ ----------------- ~
|  ~ P                 ~
|  ~ 3                 ~
|  ~ ----------------- ~
|  ~ P                 ~
|  ~ 4                 ~
|  ~~~~~~~~~~~~~~~~~~~~~
|  
--------------------------------------------------
 

If your calculator still doesn't work, try to restore the original configuration: remove the switch and the 1pF cap and put back the old C9 (27pF)
If this is working you may try to use 2pF instead of 1pF (if you don't have a 2pF capacitor connect two 1pF capacitors in parallel) this is more stable but makes the TI "only" about 2.5 times as fast as with the original 27pF.

Michael Melgares <spyder@iwl.net> suggested to do this if you don't want to short circuit your calculator: Take out the batteries and put in some new ones. Once this is accomplished you can turn it on. Then you send your calculator (if your calculator can't get into the link menu) a mem backup. This should give you an error message. This time you should be able to get into the link menu and give yourself another memory backup and you are set.

Note: Please don't e-mail me if something goes wrong, I'd like to help you, but I'm quite busy and I couldn't do anything else than telling you what I have already written on this page, sorry.

However...

As long as you take your time and carefully follow the steps listed on the page almost nothing can go wrong ;-)