Atari 2600 JR PAL help identifying a resistor ?

[maxximus]

Hello all,

 

Just a quick question, newbie here playing around with an atari 2600 Jr that has perfect picture but static sound. No gaming sound can be heard at all just static.

 

Have replaced several components without any luck including the transistor (sound) RF and voltage regulator as well as the sound caps.

 

I have noticed when the Atari is plugged in and I run my finger over the transistor shown (circled in red in pic) the sound goes all funn and the picture fades out, not sure if that is suppose to happen but was thinking to replace it if only I could identify it

 

All help is much appreciated

 

thanks in advance for your time

 

Cheers

Edited January 12, 2016 by maxximus

[+Stephen Moss]

The coloured stripes on the resistor indicate its value although it is hard to tell exactly what they are from that photo as to me it looks like either...

Brown, Blue, Black, Brown = 1K6 (1600 Ohms) or

Brown, Blue, Black, Gold = 160 Ohms

 

Looking at the circuit diagram for that section of the PCB the nearest value is 1K5 (1500 Ohms, Black, Green, Black, Brown), if what I am interpreting to be Blue is actually Green then that is probably what it is and if the silk screen underneith it indicates it is R21 then is should be 1K5 according to the circuit diagram.

 

As for what happens when you run your fingers over the components see what happens when you do the same thing using something that unlike your body is non conductive, if you get the same thing then it could be caused be bad solder joints on that component (just reheat them), if not then it may have been caused by the injection of signals such as main hum (which are picked up and conducted by your body) into the signal path.

 

[alex_79]

Those light green resistor-like components are actually capacitors (note that they're labeled with a 'C' and not an 'R'). Also note that the picture you posted is of a NTSC model. If it's not a picture of your actual unit, and you're sure you have a PAL one, then you can find the schematic here on atariage: http://atariage.com/2600/archives/schematics_pal/Schematic_2600_Junior_PAL.html