I've been working at refurbishing two Intellivoice units for a friend, as well as his own Intellivision. Until I started working on them, his Intellivision and the Intellivoice units were all finicky in terms of working together, even using my console with the Intellivoice units. I've gotten both Intellivoice units working perfectly with my own console, pretty much plug in the unit, then the game, then go, but his Intellivision has a bit of a quirk to it.

Basically, I plug in the Intellivoice, plug in the cart, and when I power it up, I have to hit the reset, or hold the reset when flipping the switch and then release, to get it to work. Otherwise, it's a black screen until I do. The console works fine with just the cart and no Intellivoice. With the Intellivoice, quirky even with a non-voice cart. While it works after the reset every time, I'm curious as to what could be wrong. I did try a different power board (but not the transformer) from a 'dead' unit, and verified that the quirk was still present, which implies it's on the main board.

If it helps, my serial # is 756952, his is 940666, which may bring in considerations of age and location of manufacture.

Thanks in advance.