Tele-Games Trouble!

[SnapCraft]

OK so I have few Intellivisions. I decided to try to repair the 2 that are not working. Both went to black screen after turning on and after hitting reset. I fixed one by replacing transistors Q1 and Q2. I did the same on the Tele-Games and it still isn't working.

 

Here's what it is doing --

 

1) After turning it on it does not display "Matel Electronics presents". Everything else is there. The color test, the title of the cart, and copyright. No glitches. (Is that normal for Tele-Games? I highly doubt it.)

 

2) I can leave it on that screen forever, no problems.

 

3) Once I select a "speed" (as most Intellivision games) it goes to the game for 1 second then either black screens or glitches as seen in pic.

 

Here's what I've done --

 

1) Cleaned everything.

 

2) Replaced Q1, Q2 and both of those mother caps at the top of the power supply board.

 

3) I've tried the mother board with a working power source and power board. I've also swapped good chips with it (only the easily removable ones).

 

I'm stumped.

 

[+intvsteve]

Not showing 'Mattel Electronics Presents' is standard for Sears consoles -- they use a slightly different EXEC ROM.

 

Beyond that I can only guess. Better qualified troubleshooters will certainly chime in soon. Guesses would be RAM chip, bad connections to RAM, etc. Is that Major League Baseball? Interesting that it's showing a 1984 copyright.

 

I suppose it could conceivably be a bad EXEC ROM... What happens if you try an Imagic game, or late game like Bump 'n' Jump? Those bypass the EXEC IIRC.

[mr_me]

Yes, the title screen is normal. The sears intellivisions have a modified exec rom that wipes out that text. I wonder why they did it that way. I think it would have been easier to change the text in the grom.

 

What chips have you swapped out for testing? The usual suspects are stic and system ram.