ATARI light sixer - grey shades unless I change channels - Odd issue...

[NISMOPC]

So, I have a light sixer. When I turn it on it is black & white (grey shades). If I switch between B&W and color, there is definitely a difference in shades of grey. B&W setting is more defined where color setting is lighter shades of grey. All graphics appear on the screen, so not missing anything there.

 

Here's where it gets odd. If I change the channel on the TV (tube TV) from say 2 to 3 then back to 2, the console is in full color. Perfect picture. As soon as I power off the unit and turn it back on, color is gone. This does not matter if I am on channel 2 or 3 on the console or the TV. Just changing the channel and then going back to set channel do I get full color.

 

I have tuned both the color and red tower pods with no positive results. Still grey, no color.

 

Using an RF to COAX adapter. Works perfectly with all my other units.

 

Thoughts?

[RamrodHare]

I had a similar problem with one of my TVs. It's an HDTV, so not the same thing, but it was clearly the TV that had the issue in my case. If I were to guess, I'd say that the RF output on your light sixer was weak. That's just a guess, since you said other consoles are working, that leads me to believe that it's not the TV, although it still could be.

[NISMOPC]

Well, I decided to take it apart and look around.

 

The only thing that seemed out of place or a potential issue is the cap located at C211 - Cap. Ceramic Disc 47pF (50V). Looking in the FSM, it shows that this cap is directly related to color issues on the light sixer.

 

Does this cap look like it's seeping or seeped? Do disc style caps actually seep?

 

Also, if I am reading the FSM correctly, it states that a Cap. Ceramic Axial 22pF (50V) is an alternate part that can be used.

 

Thoughts?

 

Edited December 1, 2017 by NISMOPC

[nick3092]

Ceramic caps dont leak or seep. And are generally very reliable.

 

Im not sure what that is on the bottom of that cap. But if you replace it, make sure you get one that is rated NP0 or C0G. That is a specific rating on how the cap handles temperature changes. And NP0/C0G is one of the most stable rated.

[NISMOPC]

Ceramic caps dont leak or seep. And are generally very reliable.

 

Im not sure what that is on the bottom of that cap. But if you replace it, make sure you get one that is rated NP0 or C0G. That is a specific rating on how the cap handles temperature changes. And NP0/C0G is one of the most stable rated.

I bought some 47pF 50V Ceramic Disc Capacitors off ebay. Should be here in a couple days. I have no idea of the rating as the listing didn't not list any reference to NP0 or C0G.

 

As you stated, I have no idea of the discoloration on the disc either, but it stood out as an indication of potential issue, so hopefully this takes care of it.

[nick3092]

When you get them, check the coefficient on them. If not NP0/C0G, dont bother installing them. You could run into other issues if you use something with a different coefficient. As the temperature changes, so will the value of the cap. Which could lead to other odd issues.

 

With ceramics its always best to put in the exact cap the engineers specified. They picked that specific rating for a reason.

[NISMOPC]

When you get them, check the coefficient on them. If not NP0/C0G, dont bother installing them. You could run into other issues if you use something with a different coefficient. As the temperature changes, so will the value of the cap. Which could lead to other odd issues.

 

With ceramics its always best to put in the exact cap the engineers specified. They picked that specific rating for a reason.

Well, appears these are NOT NP0/C0G. At least there is nothing in the specs to identify this. Just received them today and they are about 1/4 the circumference of the original one. TINY!

 

[nick3092]

Yeah. Thats why I usually stick to reputable electronic suppliers (Mouser, Digikey, Console5, etc..) instead of eBay for parts. eBay is often full of shoddy and knock off parts.

 

If you go Mouser or DK you can custom pick your parts and confirm the data sheets. You also know you are getting genuine parts. A quick search on Mouser shows a couple 47pf ceramics that are NP0, and well above the 50v rating. Granted your going to pay almost as much for one cap than 20 from that eBay seller. But at least you know what you got.

 

Console5 sells name brand/quality/genuine electronic parts as well, but mainly focuses on parts with higher failure rates and not random capacitors that may have failed. Mainly electrolytic caps in kits, which are known to fail with age. And other caps that are known to fail, like the green chicklets and 820pf audio caps in 2600s.

Edited December 6, 2017 by nick3092

[dphirschler]

I have a spare I'll send you for the cost of the envelope + stamp. I happen to have a mostly stripped board with that part still on it. So just to be clear, it's not a new part, but it doesn't appear to be "leaking" either.

 

Darryl