Can the RF Mod even work without 12VDC supply?

[walldog1]

I received an INTV 2609 to get a Mod kit added to it. Customer said it was in good working condition. When I received the package, there was no sign of shipping abuse or damage. I plugged it in to test it out to see how it played before taking it apart to add the Mod kit. However, all I got was a black screen that would flicker when pushing the reset button. Hmmm.

 

I talked with customer and he said it worked 5 months ago when he put it away. His only concern was if I could still find and fix the problem. We agreed to my usual full tear-down, cleaning, testing, and replacing any bad parts and preventative maintenance parts if needed in Logic Board as I have no idea of it's repair history. Once working, then I would do the Mod kit.

 

Without boring you, I found a via that showed no signs of ever having been soldered. I have seen vias open up due to storage and/or usage conditions in the past but there would be some solder around the via. This open via is what supplies the RF Mod with it's 12VDC supply. I pulled up a picture of a different board and circled the via that was open as I am too lazy to go downstairs and take a picture of the actual board currently. I circled in red the via right next to channel select switch.

 

My question to all of you is this. Could this console have ever worked without 12VDC at the RF Mod? Can the Rf Mod get power from the sound and video feeds only and actually work?

 

The board is a late 1981 vintage, no mention of Rev # or anything else. It is also unique in that it uses the 4 bit for Hi/Low RAM, and 8 bit for the "other" RAM near the RF Mod. I have only seen a couple of this style. It also was missing four 0.1qF Caps. I am quite sure this Logic Board was never opened before. I have seen the missing Caps in quite a few rebuilds. I always add them from my spare LB's. The end result is always a fine functioning console. Did the engineers think these Caps were unnecessary and left them out of the later production models to save on costs? These missing caps are mostly in the Q1 & Q2 area of the board. I have seen up to 8 missing Caps before on a single LB in the past.

 

My main question though is the open 12VDC via that eventually ends at the RF Mod. I suppose the customer could be confused and sent a different console than he was thinking about? I look forward to your thoughts and replies. Thanks all! If you want to see the actual LB, I will take a picture.

[walldog1]

Update: I talked with the customer and that is the only Intellivision he owns. So...... maybe the via was just making contact with both tracings by the skin of its teeth, and finally it lost its connection during the shipping process. Anyways, it still needed another 150 or so solder touch ups anyways so good thing he decided to Mod it. He is the 2nd owner, and I was glad to inform him that he has a very nice Logic Board & power supplies both AC & DC. I already replaced Q1 & Q2 transistors, and it needed the 10qF caps as well. No need to check 47qF as it is for the RF Mod which will be gutted for the Mod outputs.

 

All removable IC Chips tested good if you were wondering.

 

I have yet to look at the controllers to see their wear, or lack of hopefully for his sake.

[ChildOfCv]

Vias are made by electro-plating, just like the traces themselves are.  It's conceivable that the board has swollen slightly and broken the connection there, especially if it wasn't soldered.  It may be a good idea to run a wire through the VIA and attach it to the trace on both sides.

[walldog1]

10 hours ago, ChildOfCv said:

especially if it wasn't soldered

Yes, it was never soldered at the factory is my observation. All other boards are always soldered at that via.