Atari 2600 "Heavy Sixer" RF power issue from pin 11 of J101 Ribbon

[bszarek001]

Hi Everyone,

 

Wondering if I could get your expert opinions... I have a Sears Tele-Games Heavy Sixer I'm currently in the process of restoring. I'm getting +11-12 vdc at J204 (power plug) and it's disseminating just fine to the 7805 Voltage Regulator, where I'm getting exactly +5 vdc. Perfect.

 

However, I'm getting no video output whatsoever. I test the voltage at the RF modulator, pin 2 (on a 3 pin RF board) and I'm getting nothing. So I trace it back to pin 11 of J101 (12 pin ribbon at the top). According to the schematics, this should be providing +5VDC to power the RF board. I tested all the points along the back of the board and I'm getting nothing. Yes, I know there is a capacitor there, but it wouldn't matter in this case because I tested at pin 11 at J101 and it's providing no power at all even though at pin 1 of J101 I'm getting +5VDC and at pin 2 of J101 I'm getting +11vdc or so (which is correct, according to the field manual). So it would appear that there is some kind of short or break in the PCB at pin 11 causing this issue. What I'm wondering is this -- can I jump pin 11 at J101 with another +5vdc power source, possibly even pin 1 of J101? I don't want to try it and potentially ruin this really beautiful heavy. If not at pin 1, where else could I jump from that would be safe? Maybe one of the points past the 7805 after the power has been regulated to +5?

 

I did test continuity along the 12 pin ribbon J101 and there appears to be satisfactory continuity and checked for cold solder joints, re-flowing a couple but it didn't help.

 

Any help would be greatly appreciated. Wanted to get an expert opinion before I try jumping this and potentially ruin the entire board. Thanks!

 

Edited December 1, 2017 by bszarek001

[dphirschler]

Interesting. You got no replies to this topic here, but a load of replies/support on the FB group.

 

Darryl

[bszarek001]

Interesting. You got no replies to this topic here, but a load of replies/support on the FB group.

 

Darryl

Yeah, I know how it is sometimes, though. This is a forum not a facebook page, where it shows up on people's feeds while they're sitting on the shitter.

 

I did end up having to jump pin 1 to pin 11 and had to replace the 7805 and hard wire it in to the next solder points on the pcb, as all the pads were lifted.

 

It isn't pretty, but it's working, and that's all that matters.

[dphirschler]

Hey Brian. Pin 8 wasn't working on mine and I discovered it was the ribbon cable. No need to jumper.

 

 

Just a thought. You might be able to remove that jumper if you also have a bent pin. Something to check anyway.

 

Darryl

[bszarek001]

Hey Brian. Pin 8 wasn't working on mine and I discovered it was the ribbon cable. No need to jumper.

 

IMG_20171211_211904.jpg

 

Just a thought. You might be able to remove that jumper if you also have a bent pin. Something to check anyway.

 

Darryl

 

 

Hey, thanks for the info.. I had thought of that and considered it a real possibility, but didn't want to go through the hassle of removing that damn ribbon. Do you know of anyone that has any of that style ribbon (new old stock or salvage) for sale? I doubt Best would since only the heavies used them and I couldn't find any on ebay. Thoughts?

 

Thanks!

[dphirschler]

I just heard from Brad at Best Electronics. He has the 12 pin mylar cable in stock for $8.95. Mine is not the mylar style. But you may be in luck.

 

Darryl