Intellivision graphics corruption

[kevincondrick@gmail.com]

Ok well I just got an intellivision and to play some of the classics for the 80's. Now when I start the game it will work for like maybe a minute or 2 then when graphics will corrupt and everything just freeze the game. I have a little knowledge when it comes to this. First off I tryed swapping chips around and I know it's not the the ram,cpu or the stic chips cause I swapped them out and it all works fine on my ini2. So I'm thinking it's one of the ROM chips but idk which one or if it could be something else. If anyone can help that would be great ?

[+intvsteve]

A couple other ideas are that it could be heat-related insofar as cracked solder joints on the board. Maybe check the connections between the STIC and RAM to be sure they're good.

 

How's the condition of that super-frail ribbon connector between the mainboard and the power board? That thing has given me so much grief over the years.

 

It may also be a component (cap, diode, etc.) that's failing as it warms up, too, though you'll want someone with a good understanding of that aspect of the board to chime in. I've only dealt with chip-swapping as a debugging method along w/ test ROMs.

[kevincondrick@gmail.com]

Alright I might have to check that out I know the ribbon cable isn't good so maybe I'll try replacing that. 

 

I also thought it could be heat related. If I would shut it off and let it sit for like 5 mins it will work again but still will do the same thing. I couldn't find anything really warming up though. I'll give it another look over and see what I can find. 

 

Edited April 20, 2020 by kevincondrick@gmail.com

[IMBerzerk]

Believe it or not, that cable will work well even if it's delaminated.  Use a MM with the connectivity test.  If you get tone, you should be good.  Check ohms as well.  Should be "0".  

 

Heat will drive you insane on these things.  Visual check of the board will sometimes yield good results.  

 

I don't think it's chip related.  You can also test voltage at the test points on the power board.  Before and once it's heated up and giving fits. 

[kevincondrick@gmail.com]

2 hours ago, IMBerzerk said:

Believe it or not, that cable will work well even if it's delaminated.  Use a MM with the connectivity test.  If you get tone, you should be good.  Check ohms as well.  Should be "0".  

 

Heat will drive you insane on these things.  Visual check of the board will sometimes yield good results.  

 

I don't think it's chip related.  You can also test voltage at the test points on the power board.  Before and once it's heated up and giving fits. 

I did check that ribbon cable it comes up with continuity on all the pins. Also if I leave it on I noticed that the transformer gets warm. You think that cold have anything to do with it?... I believe all the voltages on the output was correct tho.

 

 The main 2 capacitors are my thoughts. I don't know what the rating of them or how to test them.

[kevincondrick@gmail.com]

 

I saw this to that one big white thing there was all bubbled up but idk what it was it also looked like it got warm over time. So that might be the problem.  The backside however all the solder looked like it was in tacked I tryed to reflow that already but it looks ok I think.

[mthompson]

Those two transistors can also go bad, and it's a cheap & easy fix. Your board looks pretty baked in that area.

 

Here's the thread I created to document what was wrong with my Intellivision (it turned out to be those two transistors): 

But you're right about that white component looking suspect. Good luck.

[kevincondrick@gmail.com]

2 hours ago, mthompson said:

Those two transistors can also go bad, and it's a cheap & easy fix. Your board looks pretty baked in that area.

 

Here's the thread I created to document what was wrong with my Intellivision (it turned out to be those two transistors): 

But you're right about that white component looking suspect. Good luck.

I believe it is that one transistor there I did notice it was getting warm so I'm going to ordered some up and replace it. Thanks for the recommendation ?

[IMBerzerk]

I agree.  From your pics posted, they look exactly like the issues 2 other owners had with their boards.   It's worth the shot at replacing them.  That thread should be pinned.  It's a very good one for fixing these things!

 

Good Luck!

 

Let us know how you make out.

[kevincondrick@gmail.com]

Well I changed both of the transistors but it still dose that same thing I also changed the one rom chip that dose the graphics ... So I really don't know ? idk if it's cuz it's still hot but I'll try it in a bit and see.

 

[kevincondrick@gmail.com]

Also I changed all the capacitors and still dose it. I'm feeling like it's definitely heat related but the only thing I know that heats up is those transistors. That's normal as far as I know.

[kevincondrick@gmail.com]

Hears what happens. The only noticeable thing that get hot are the 2 transistors and the transfer its self. I just thought that was all normal tho