2600 Jr. Recap Woes

[qrysdonnell]

So after my issues with my composite mod (which are probably just problems the system had all along but I didn't notice) I got a recap kit from Console 5 for a few of my systems in my spare pile to see if I could fix them up.

 

The first 'victim' was a Jr that I had which had a pretty similar output to the system I put the composite mod in. Since my problem last time was an issue which may have been there beforehand that I just didn't notice since it wasn't a system I normally used, I decided to take it slow and document every step of the way and this Google Slides presentation has all of my pictures...

 

https://docs.google.com/presentation/d/1csaTT7zJL5_K1UutVZk4IrXtmG32HbMwhzJcsNbbfOA/edit?usp=sharing

 

As you'll see in slide 2, the colors are very subdued compared to my main unit, which is a light sixer. Very noticable on something like Yars Revenge.

 

I replaced the large capacitor (C26), and noticed no change

 

Same with C20.

 

After C27 still the same.

 

After what I think is C37 the picture looked good for a few seconds before reverting to looking like it had before. I wasn't able to get a picture, but it essentially looked like my reference. (C37 was harder than the others to deal with, as it was put in with a resistor going into the same through hole and it was hard to get it all out, get the holes cleared and everything put back - I actually wasn't able to get the resistor leg back through, so I soldered it on top. It looks like this cap wasn't in the place marked on the board for some reason.)

 

I moved on to the voltage regulator which I had the hardest time of all getting the holes clear enough to put the replacement in, as such the area doesn't look too pretty. When trying to turn it on I don't get any picture. LED goes on and I can tell from the change on the screen that it thinks it's on, but no picture. I also can't see any notable difference turning it on with or without a cartridge.

 

I don't really know my way around a multimeter enough to really test, but using the 'beep' function I can tell that I'm getting connections between the parts of the VR and the next spots there's a solder point on the board and I am not detecting any obvious solder bridges, etc.

 

So what to do now? What's the next step to determine if this is salvageable? I don't really know how to test a PCB or components properly, so I may have to start learning that.

 

Could I just have a bad voltage regulator? I had to cut the leads off the old one to get it out with my poor desoldering setup, so I can't easily put it back without hobbling something bizarre together (may try it at some point, but I've had enough for today!). I do have another new voltage regulator because I got two cap kits, but I don't really want to potentially ruin that one yet.

 

I'll troll YouTube to watch some Atari repair videos later, but figured I might get good advice here.

 

I do have a better desoldering solution on the way, so at least the next system might not be as unlucky!

 

Thanks in advance for any help!!!

[qrysdonnell]

So I watched enough YouTube to get a vague idea of how to take voltage readings with my multimeter, as best as I can tell I think I’m getting okay readings from the voltage regulator (5v on left most pin, middle is ground and 9v on right most pin) the next spots in the circuit that I traced seemed to be fine from what I could tell as well, but it’s not like I really know what I’m doing.

 

Maybe I heated the board up to much while trying to clear the holes for the voltage regulator and killed a different component. I’ve no idea how to identify that yet though, so who knows!

[+wongojack]

It sounds like you are going about it the right way.  Lots of things can go wrong with this process.

 

When you get de-soldering equipment, you should put the system back to it's last known working state.  In that case it means re-connecting the old voltage regulator.  Even with short legs, you can connect it via wires.  Be careful and get it right.  If you get the same result with the old regulator then you know something else has gone wrong.  It could be something physical, de-soldering with a wick (if that's what you did) can force you to move the board around or press on components or both.  It is possible that something just kinda came loose.  Look for capacitors or other components that may have become disconnected.  You might be able to spot the problem just by looking.

 

If all else fails there are lots of people on these boards who will fix it for you if you send it to them.  They can also probably help you with the original problem you were having with the color.  If you end up wanting a service like that then post in the "Wanted" forum, there are several members who do mods as their main business.  @-^CrossBow^- is one who really knows what he is doing.

[slacker]

Shot in the dark, but did you try turning the color tuning potentiometer on the board to see if it gets any better?  (The 4 switch & 6 switch have it, not sure of Jr... never messed with one).

[+wongojack]

@qrysdonnell is this you?  Did you get it working with a new TIA?

 

[qrysdonnell]

7 hours ago, wongojack said:

@qrysdonnell is this you?  Did you get it working with a new TIA?

 

Nope. (My normally spelled name is Chris Donnell). These dark 2600 woes are going around.

 

I looked over the board a little more today and I can’t find anything that looks bad about it now (since it’s now extra dark). I may redo some of my work when I get better equipment Sunday.

 

I do wonder if the few seconds of it looking good after the last cap replacement meant that something is wrong that killed the cap shortly after it was put in. That cap is the one right by the on the color pot, so maybe it has something to do with to?

 

Most of the 2600s I have came from electronics auctions in Phoenix in the late 90s and mostly sat in an garage in Phoenix before ending up in a basement in Atlanta and now they’re in my fake video game museum in New Jersey, so they definitely weren’t well taken care of. I have a 4 switch that I mentioned in another thread that I did a composite mod on that has a very similar dark look to it and I think I remember having a few in my collection that are worse. Maybe I’ll figure it all out eventually?

[+wongojack]

While a brand new capacitor failing would be rare, that is a good idea.  A tried and true troubleshooting technique for when you cause damage is to go backwards over what you have done and re-do it.  Another good rule is to only change one thing at a time to isolate precisely what is wrong.  If you swap out 3 or 4 things and fix it, that's great but you learn less about what is wrong.

 

And not all composite mods are the same.  Many of the simple mods create odd color variations and other issues.  I've never done one, but I've heard the Jr. is especially prone to being dark.  I've honestly become convinced that a composite mod isn't really worth it anymore.  Good S-Video or RGB is nice for the upscaler crowd, but if you have a good CRT then I'd stick with RF.

 

Still - there are people on these boards that have been dinking around with those AV mods for at least 3 decades.  There is probably some adjustment to the mod that someone can help you with to brighten things up.  Posting in the "hardware" sub-forum often draws a different crowd with different responses.

[qrysdonnell]

On 3/20/2021 at 9:25 AM, wongojack said:

While a brand new capacitor failing would be rare, that is a good idea.  A tried and true troubleshooting technique for when you cause damage is to go backwards over what you have done and re-do it.  Another good rule is to only change one thing at a time to isolate precisely what is wrong.  If you swap out 3 or 4 things and fix it, that's great but you learn less about what is wrong.

 

And not all composite mods are the same.  Many of the simple mods create odd color variations and other issues.  I've never done one, but I've heard the Jr. is especially prone to being dark.  I've honestly become convinced that a composite mod isn't really worth it anymore.  Good S-Video or RGB is nice for the upscaler crowd, but if you have a good CRT then I'd stick with RF.

 

Still - there are people on these boards that have been dinking around with those AV mods for at least 3 decades.  There is probably some adjustment to the mod that someone can help you with to brighten things up.  Posting in the "hardware" sub-forum often draws a different crowd with different responses.

This particular 2600 only had the recap and voltage regulator swap done. It's a different 2600 that has the composite mod which has what I would now call poor color saturation (and it may be primarily on reds?).

 

This one had similar looking video (it's actually darker) and I embarked on recaping the unit to see if that would resolve it. I went through all of the caps and the last one may have made a difference but it only lasted a few seconds. Then I replaced the voltage regulator and it hasn't worked since.

 

I have since put the old voltage regulator back (I've added notes to the Google Slides document above) but with no changes. As best as I can tell the regulators are regulating properly (tested with meter) and the continuity of the solder joints seems to check out.

 

I did struggle to both get the old VR out both in general and to get the holes cleared enough to get the new one in, and this resulting in me perhaps applying too much heat, so the most likely issue is that I fried something. But I haven't been able to find out what I potentially fried and if I might be able to repair it. Nothing near the point where I took the VR out seems to look too bad, and everywhere I've tried to check continuity seems to check out.

 

I haven't heard any good ideas, so I'll probably stick it in storage for a bit and come back to it later after I've messed around with this stuff a little more. I do have a better desoldering solution, so I'm less likely to have to cook another board! I suppose I might have to go component by component and remove and test each one, so I'll need some real patience for that!