Videopac / Odyssey2 forum

Videopac / Odyssey2 => Hardware => Topic started by: Pickaxe Brad! on June 09, 2022, 05:13:41 PM



Title: Bad joystick chip (612197-1 7927). Any options for replacement?
Post by: Pickaxe Brad! on June 09, 2022, 05:13:41 PM
<issuehistory>
Something must have happened to my O2 a couple months ago  because all of a sudden one of the joysticks was acting like the  ACTION button was permanently pressed.  Standard debugging had me swap joysticks' and eventually lead me to do a continuity test on the pins.  Sure enough, the fire pin was connected to ground (tested from the joystick port).  After unnecessarily desoldering the joystick connector, I removed what I think is the joystick chip (labeled 612197-1 7927). And I found the issue: the completely disconnected chip is pulling the pin to ground.
<~issuehistroy>

I'm happy-ish that I'm "close" to having fixed this issue, especially as desoldering is a new skill for me. But, before I press my luck to far and end up breaking something, I wanted to report my progress on this forum and see if I anyone knows of a place I can purchase a 612197-1 7927 chip and if I were to find one, would it be a drop-in replacement or does it need to be flashed or programmed somehow?

Any info/help is appreciated and it will prevent me from trying out crazy ideas like trying to use the outputs from the one good joystick chip and having it drive the second controller as well.  Probably a really bad idea I'm likely to try out if left to my own devices.  :D


Title: Re: Bad joystick chip (612197-1 7927). Any options for replacement?
Post by: Xuul on June 10, 2022, 04:39:05 AM
This IC could be a suitable replacement ( random shop, just for the IC description ).
https://vetco.net/products/nte74ls365a-ic-ttl-3-state-buffer (https://vetco.net/products/nte74ls365a-ic-ttl-3-state-buffer)
There are a lot of these on eBay.

Or just buy a cheap, broken Videopac to cannibalize  :)




Title: Re: Bad joystick chip (612197-1 7927). Any options for replacement?
Post by: Pickaxe Brad! on June 10, 2022, 05:26:16 AM
Or just buy a cheap, broken Videopac to cannibalize  :)
I considered that, but I don't think I can desolder chips without breaking off a few pins.  I broke 5 getting this chip off.  :o

Many thanks for the info!  It looks like I'm only $5 away from fixing this system!