View Full Version : Twitchy TI 99/4A

June 5th, 2009, 06:24 AM
I am the new owner of a TI machine and unfortunately it has an issue which is troubling me.

The unit came only with the modulator and power adapter, It powers up fine and i get the start screen with the TI logo and colored bars and such, it says press any key to start and when I do it goes to the next screen which instructs me to press 1 to start TI Basic, when I press the one key it will either go back to the TI logo screen or a screen where the message "TI Basic system ready" will flicker briefly across the bottom or the computer will simply freeze.

Is this a common error with these systems or have I stumbled across a new problem?

The computer is the silver/black model.

So far I have tore down the unit cleaned and re-seated the keyboard and cartridge connectors and the grease and heat sink are in good shape(grease not dried out and no signs of burning) after reassembly the unit powers up fine but the aforementioned problem persists.

Any thoughts or help would be greatly appreciated.

June 5th, 2009, 07:40 AM
Sounds like a bad RAM chip.

June 5th, 2009, 03:17 PM
Do you have access to any TI cartridges? If so, insert one and then press its selection on the second screen instead of TI BASIC. If that works, both the CPU RAM for the workspace registers (1K) or the VDP RAM (16K) are OK, leaving the most likely cause a corrupted TI BASIC GROM.

June 5th, 2009, 03:40 PM
Unfortunately I do not have any carts for the console yet I will trying to get some soon.