Jump to content

Ti 99 4a with a ti 99 4 power pack and internal board help

Recommended Posts

This is my TI-99/4 power unit that came in my 1980 TI-99/4A. Orange wire should be +5v..but i get -6.71 vdc, black wire should be +12v..but get -11.99. And green wire should be -5v and i get -17v.


So i would think it fried my motherboard.


What could have went on this to cause such voltages? And yes :) i have right wires on my fluke going to white wire common. :P


I think the fault is this brown cap but dont know what it is..any ideas?


If i can get motherboard working..i have an idea for a replacment wall wart and power board replacnent with a very available and common wall wart. (details on this to follow).





Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Create New...