Re: TI-H: Accellerating an 85

To: ti-hardware@lists.ticalc.org
Subject: Re: TI-H: Accellerating an 85
From: "Richard Piotter" <richfiles@hotmail.com>
Date: Thu, 25 Sep 1997 10:10:43 PDT
Reply-To: ti-hardware@lists.ticalc.org

>the value of c9 is said to be 33pf, and 22pf. I have tested both and 
found
>22pf to be the closest value of c9. (If you use a 33pf with a switch,
>normal mode is SLOWER than with no turbo at all! 22pf is more accurate)
>
>I did have several show lines on the screen...at first I thought I was
>screwed, but I found out that the switch was being shorted by one of 
the
>lithium battery contacts. to fix this, put electrical tape all around 
the
>switch and on the metal shield.  Double check to make sure your switch
>isn't jamming down any any components and make sure there are no short
>circuits. I have actually FRIED batteries in my 85!! (I nearly burned 
the
>battery case :) )
>
>>Okay 8 timer... what the hell is the value of c9 and have you ever had
>>one give you lines on the screen when you switch to turbo?

I had one calc fail. Replacing C9 didn't help. I was getting pretty damn 
scared till I looked closer at the board. If you scratch the white paint 
off that outlines C9, then you will see the tiny copper traces that C9 
connects too. They are extremely tiny, and easy to damage. If you over 
heat the board while removing it, it may pull the wires off the board. 
You need to make sure not to damage the wires.


             C9
    ___      ___
   |   |____|   |____      |\_
   |___|    |___|    \     |  \__
   |R11|              \    |     \_
   |_?_|     ___       \   |       \
   |   |__ _|   |_ __   \__|  U4    | 
   |___|  ^ |___| ^  \_____|         \ 
          |       |        |          \
          |_______|        |          /
          |                |_________|
   Copper Trace Breaks
   Here often if heated
   too much or too little

Richard Piotter

e-mail: richfiles@hotmail.com

home page: <A 
HREF="http://www.geocities.com/SiliconValley/Lakes/5081/Richfiles.html">The 
Richfiles</A>

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