2600 Junior No output

[Dopy25]

I posted a week ago about a junior I bought and boned the main capacitor. Well I got a new cap and replaced it, and the voltage regulator. The unit seems to get power on all chips but I can't seem to get any video output at all! The screen changes static but that's about it.

 

I am using an NES RF cable as that is all I have around. Is the JR supposed to get 5v at the RF port like other consoles? I'm getting nothing. I ordered one of those RF/coax adapters that will be in tomorrow but I thought the NES box still worked for these.

 

I reflowed every solder joint on the board and have the same result.

I tried adjusting L6 to get an image with no impact.

I also tried the 500k pot and still nothing. The 500k pot is a bit browned, is that normal? I will add a pic of the pot.

 

As far as what I see on the screen, it is literally static, as if nothing was plugged in at all. I have read other posts with the same result and notice that channel is a common thing. I tried channels 2, and 3 with no luck. I am using an older TV, CRT with coax input. I tried switching the RF output on the jr. 

 

I am only using carts not known to work, but I should still see a black screen, right? Shouldn't there be some sort of signal going to the TV?

 

Does it have to have some sort of video output to do a composite mod? I paid $25 for this thing with a controller so I don't want to toss a bunch more money at it. I really wanted to get into Atari and thought I got lucky finding this for that price (even "untested") but at this point I think I made a bad decision and I really hope that's not the case.

 

Any advice?

Edited November 24, 2020 by Dopy25
Add pics

[Dopy25]

It's alive! Sorta. I got picture finally. I made an adapter and soldered an RCA cable to a coax cable and got this. I was able to fine tune some color by adjusting L6 and the 500k pot at R9 again but still got a ton of static. Any thoughts on how to clear this up? Would a composite mod make this a moot point or are those components relevant to composite and rf?

Edited November 24, 2020 by Dopy25
Clarification

[ChildOfCv]

You should probably use a AV-coax F adaptor with an undamaged cable, to maximize the signal quality.  You could also try the channel switch (S3) to see if one channel works better than the other.

[Cmherndon79]

Well that's an encouraging sign there @Dopy25 .  The suggested above is good advice if you want to keep playing with RF out.  Personally, now that you've verified it works, I'd just convert it to RF output, as it seems like you've got the skills and tools.  You can purchase a kit with a PCB, the needed transistor and resistors and RCA jacks for $10 shipped off eBay.

[Dopy25]

I have a coax-F adapter coming tomorrow from Amazon.

One of these: https://www.amazon.com/gp/product/B06XSL31B3/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

Is this the right one?

 

I am also looking at composite output boards but wanted to see if the clarity issue I have would have any effect on an RCA mod.

[ChildOfCv]

That's the correct adaptor for using an AV cable to reach the TV.  Personally, I've had better luck with the one that's made for running coax from the TV, but YMMV.

https://www.amazon.com/VCE-2-Pack-Coaxial-Adapter-Connector/dp/B01N80QQ1F

 

[Cmherndon79]

1 hour ago, Dopy25 said:

I am also looking at composite output boards but wanted to see if the clarity issue I have would have any effect on an RCA mod.

Fairly certain all that snow on the screen is a not optimal RF issue, either with the cabling the onboard RF modulator.  Some of the Woody/Vader 4-switchers have under-rated caps that cause snow, but nothing in the severity of what you're seeing.  I'm pretty sure if you convert it it will clear up the signal over composite.

 

Also, another thing you might want to consider if you do decide to convert it to composite:  The Jr. cases are very fragile in comparison to earlier models.  You've got to be extra careful if you drill into a Jr case.  When I do drill into them to install jacks, I move up from 1/8th to 1/4 one size at a time. I prefer to stick to dedicated RCA cables tied down and running from the rear from where the RCA RF port was prior.

[Dopy25]

Thanks for the input. I already bought the one for coax at the tv and I have a pretty good quality RCA av cable to make it there. The one I used in the above pics was just something I had lying around and snipped it up. Pretty Terrible quality, tbh. 

 

I don't plan on drilling into the case at all. I can't find the "deluxe" boards at a reasonable price shipped to the states, so I plan on buying the board from eBay and using one of these in place of the RF port:

https://www.amazon.com/dp/B07BHBQ5YV/ref=cm_sw_r_cp_apa_fabt1_p-AVFb9VMSPAW?_encoding=UTF8&psc=1

[Cmherndon79]

Looks like a pretty reasonable solution, assuming the height dimensions work out.  Probably will, just eyeballing it.

[Dopy25]

I went with a different solution but had a positive end result! I grabbed an av mod kit from eBay but didn't use the included connectors. Instead I bought a 3.5 Jack and used that with modification. Check it out. I ended up having to route the cable a bit different.

 

Edited December 9, 2020 by Dopy25

[Cmherndon79]

I think that is a slick way of doing it @Dopy25 !  Congrats on the completion!

 

I've used a washer like that on a Genesis someone wanted me to installed a S-Video port where the RF modulator had been.  I had to dig around the parts bin at an Ace hardware to find potential matches, before I found a black nylon one.

[Dopy25]

On ‎12‎/‎10‎/‎2020 at 11:41 AM, Cmherndon79 said:

I think that is a slick way of doing it @Dopy25 !  Congrats on the completion!

 

I've used a washer like that on a Genesis someone wanted me to installed a S-Video port where the RF modulator had been.  I had to dig around the parts bin at an Ace hardware to find potential matches, before I found a black nylon one.

I will probably find a black nylon one at some point. This was in my own bin. haha

 

Black nylon actually sounds amazing. I feel like the galvanized steel looks odd, but it's what I had and I wanted to fill the rf hole instead of drilling. I'm with you on that one. Drilling an old case seems like asking for trouble.