Fryed Stella TIA on a 2600 JR - Suggestions?

[weirdaljr]

Hello,

 

While tinkering last night I fryed my 2600 JR:( I just get a black screen now, but I know when how I did it so maybe their is a worthwhile fix?

 

I was testing output voltage on pin 10 of the TIA and the probe slipped a hair with machine on and touched pin 9. Im 95% sure that is the exact second it stopped working. What did I do, fry the TIA, or a power circuit leading up to it? Any possible solutions worth it?

[Osgeld]

I hear conflicting information about the JR so based on mine, which is a NTSC version, but matches the pal schematic perfectly, just with the pal section unpopulated (the boxed in area to the left of the TIA, pin 10 goes to the color adjustment pot. Seems that one side of that pot is connected directly to the power jack through a 4.7k om resistor according to the schematic (man thats a bad deal there) so even though its divided with ground though the pot it could produce a lethal voltage to pin 9.

 

I am going to go check that out

 

and here is a link to the schematic I am looking at

https://atariage.com/2600/archives/schematics_pal/Schematic_2600_Junior_PAL.html

Edited October 12, 2013 by Osgeld

[Osgeld]

well I checked it and the way its arranged it wont go over 5 volts, sitting a little over mid way on my machine only getting 3.3... still adding in a reverse polarity diode on my machine though