2600 Jr., B&W issue, worse on Demons to Diamonds.

[RamrodHare]

OK, I didn't know if I should post this here or in Hardware, so I just put it here.

 

I just got a 2600 Jr. today and it has a few issues.

 

When you first turn it on, with any game or the Harmony cart, it takes probably 10 seconds before the picture shows up on the TV.

 

When you put a Battlezone cart in and turn it on, it takes a few seconds, then you get the radar and some other random bits of the picture kind of jumping around the screen, then it will show up correctly, but with a very dim picture. In a couple of seconds, the picture brightens up and the colors are all good.

 

If Demons to Diamonds is inserted, same wait time on start-up, but the color and brightness are good. Now, here's the big problem.

When you hit reset to start Demons to Diamonds, it goes from color to Black and White. Unplugging the rca cable from the back of the console and then slowly putting it back, will allow you to see a split second of color before it goes B&W again. The same thing happens using the Demons and Diamonds .bin on the Harmony Encore. Also, With the Harmony, if you switch it off, while it's B&W and then switch it right back on, the Harmony menu is in B&W. Switching it off and on again, results in color.

 

The Jr. isn't modded and an inspection of the board showed no bad solder joints or leaky caps. The Serial is A1781245617 The board is CO21503 Revision C

 

On most games, it looks great, the colors and the picture are better than my AV modded Vader and 7800, other than the lack of a picture for a few seconds when you turn it on.

 

Demons to Diamonds is the only game I've found so far that triggers the B&W issue, but I feel like that's a sign of something needing repair.

 

So, does anyone have an answer as to what's wrong with it?

Edited June 29, 2017 by RamrodHare

[SignGuy81]

This sounds like a bad capacitor. I know you said you inspected for leaky caps. Do you mean that you looked for bulged caps or electrolyte on the board? Or did you actually check them with an ESR meter perhaps? More than half of the bad caps I've replaced on circuit boards showed physical signs of being bad.

Edited June 29, 2017 by SignGuy81

[RamrodHare]

I just visually checked them. The only type of tester I have is just a cheap multimeter. If there's a way to test them with it, I have it apart and ready. I did test the voltage regulator and power supply. They are both working fine, I even tried a second power supply, just to be sure.

Edited June 29, 2017 by RamrodHare

[SignGuy81]

https://www.ebay.com/p/Portable-Mk328-LCR-ESR-Tester-Transistor-Inductance-Capacitance-Resistance-Meter/686241850?iid=252384901482

 

The one I showed the link to above is a LCR meter as well as an ESR meter so you can check a lot with it. I have no idea about the quality of it though I have a different brand which was more expensive and mine isn't also an LCR meter.

[SignGuy81]

Check your 5V with your multimeter to start off with.

 

EDIT:

 

Check while you power it up.

Edited June 29, 2017 by SignGuy81

[RamrodHare]

Check your 5V with your multimeter to start off with.

 

EDIT:

 

Check while you power it up.

5.04v

 

EDIT- I just noticed a 35v 4.7UF cap that the end is slightly bulged compared to the other one on the board. it also has a slight yellow discoloration near the end. I'm guessing this might be the issue?

Edited June 29, 2017 by RamrodHare

[SignGuy81]

I just noticed you already checked the VR and PS my bad.

 

5.04v

Edited June 29, 2017 by SignGuy81

[RamrodHare]

Ok, I'm not sure about the 4.7UF cap. I can't tell for sure if the end is bulged or if the plastic coating just doesn't cover as much of the end as it does on the other one.

[SignGuy81]

5.04v

 

EDIT- I just noticed a 35v 4.7UF cap that the end is slightly bulged compared to the other one on the board. it also has a slight yellow discoloration near the end. I'm guessing this might be the issue?

 

Very possible.

Do you have one to replace it with?

[RamrodHare]

 

Very possible.

Do you have one to replace it with?

I have one I removed when I replaced them on my Vader, but it says 50WV 4.7 I'm guessing the 4.7 is the important part?

[RamrodHare]

I tried to take photos of the cap to get your opinion on whether or not it looked bulged on the end, but I can't get it in focus well enough to really see.

Edited June 29, 2017 by RamrodHare

[RamrodHare]

OK, I can't explain it, but when I hooked the board up to the TV just now, everything worked fine. Demons to Diamonds, Battlezone and the Harmony Cart. They all worked fine, other than some snow from having the shielding off of the board.. The only thing I've done that I hadn't already tried, is hooking it up without the shielding. So now I'm stumped. I think I'll order a refurb kit so I can replace all the caps, just in case, but right now it's working fine. It almost makes me think it might be a bad solder joint, but I can't see anything that even looks slightly off and I don't really feel like reflowing the entire board right now. I'm going to try reassembling it and see if it still works. I really hate that it started working like this, because now I don't know what caused it. Had I actually repaired something, I would know it was fixed, now I feel like I'll just be waiting for it to screw up again. I have mixed emotions about it. I'm glad it's working, but I'm sad I didn't find what caused it.

 

Thanks for trying to help me out anyway.

[SignGuy81]

This sounds like a bad capacitor. I know you said you inspected for leaky caps. Do you mean that you looked for bulged caps or electrolyte on the board? Or did you actually check them with an ESR meter perhaps? More than half of the bad caps I've replaced on circuit boards showed physical signs of being bad.

 

 

I know this is old but in case anyone comes back to it I noticed I made an error and I can't edit this now but I just realized I said most of the bad caps I've replaced showed physical signs of being bad while I meant to type "no physical signs of being bad".

[Osgeld]

SMT electrolytic caps will crap all over the board, though hole electrolytic may not show obvious signs of being bad, unless they are REALLY bad and abused

 

looking at that image first thing I would do is dunk it in a alcohol bath and scrub the crap out of it with a horsehair brush (not plastic) which can be found at any hardware store in the plumbing section, there seems to be a bunch of crusty flux around that area, and crusty flux is a good chance of dendritic growth aka weird shit when metals (solders and wires), corrosives (flux) and water (humid barn, garage or basement) interact over time to form semiconductor like crystals

Edited July 11, 2017 by Osgeld

[RamrodHare]

there seems to be a bunch of crusty flux around that area,

Based on my photo, it does look that way, but it was actually just the lighting. I was using a desk lamp instead of a decent light source. The board is much cleaner than it appears. The board on my 2600 however... It exhibited the EXACT thing you described and cleaning it was one of the first things I did when I got it. I used rubbing alcohol and a tooth brush for sensitive gums. Most of the flux residue was on the underside of the board, so it wasn't hard to clean off. Cleaning the board is always good advice, so I'm glad you posted about it.