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Texas Instruments TI-99/4 Fixed

Texas Instruments TI-99/4 Fixed

Texas Instruments TI-99/4 Fixed

Defect:

  • Garbage screen on startup immediatly or after a couple of minutes.

Fix:

  • This defect is very similar to the one of the Coleco Vision console.

The problem are the pins oxidized of the power switch, i have sprayed R-11 and the problem it’s disappeared completely.

I left turned on the computer for more than 2 hours and i have made a 50 x power cycle (ON/OFF) and the problem is no longer appeared.

Note:

I thought there had to be a VDP RAM problem with a diagnosis made remotely without having the TI-99/4 in the laboratory.

To avoid using the lame RF modulator i have used a standard Commodore 64 composite cable that works very well with a NTSC composite video output.

Gallery:

  1. Bernhard
    April 26th, 2020 at 14:19 | #1

    Hi

    I have the same problem, the Texas Instruments 99/4 have no Picture and whistling sound when switched on.
    I have 2 more 99/4 that don’t work
    mean you the contacts on the on / off switch on the Console spray with R11 ?

    I have 2 more 99/4 that don’t work, maybe I could send them to You ?

    greetings

    Bernhard from Germany

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