7800 + UAV = no color?

[Nick15]

Hello!

So I'm trying to install a UAV into my 7800, and I'm running into a bit of trouble: the console is not sending color data for 7800 games. 2600 games, however, work perfectly fine; the photo shows B/W video on both my PVM using an S-video signal and my normal composite video in 7800 mode... but if I switch to a 2600 game, both are in color (I don't have a photo of that right now, however):

 

 

Here is a photo of my board: I removed the switch and RF modulator in order to ascertain a grounding issue.

 

Long story short: I've tried a ton of stuff but so far no dice, so I'm open to any suggestion you have to test out.

 

...

 

Long story long: here's what I've tried/attempted/considered:

• I did all kinds of searches for "7800 no color" but all of the suggestions I found involved one of the following.
• Before I removed the RF modulator, it was definitely outputting color on channel 3 (nothing on Channel 4, however), but it was still showing grey on the composite line.
  • For the record, I removed the RF modulator because the main video output pin was damaged and grounded. Despite this, I was at least able to get SOME signal output, and it was in color.
• I was told the Pause button switches between color and B/W mode, but pushing it does nothing. It also was showing color in RF mode and I haven't touched the Pause button
• I tried connecting the MCOL line from R16 directly to pin 43 on the Maria chip, but it's still in B/W
• I then thought that maybe the Maria chip itself is damaged, but I still saw color I'm RF mode while it was B/W in composite and S-video
  • Maybe U2 is damaged? But then again 2600 color works fine, and U2 is what chooses between the two signals, right?
• I thought might be the UAV itself, so I ordered another one and that still shows in B/W.
  • It's possible that both came from the same batch of UAVs which aren't working well, but I doubt that that's the case as 2600 games are in color. But surely there's a way to test this either way.
• The MCOL cable (dark pink in my photo) has been checked for continuity, and I didn't see any issues.
• I tried adjusting the 7800's color potentiometer, but no go.
• I recapped the three main caps, but I suspect those are just for the power only.

 

Again, I don't mind testing stuff or replacing parts or swapping chips, if needed that is. But right now I'm at a loss as to how to get 7800 color working and I'm open to any suggestions you may have.

 

Thanks in advance!

Edited February 17 by Nick15

[+-^CrossBow^-]

@Nick15 If you have a meter, I would put it in resistance mode and verify that you getting changes in readings on the 7800 color trimmer when you move it about. To confirm if the pause button is an issue or not, use the game pitfall as it has a dedicated BW mode and color modes. You stated you have color working in 2600 games so when pressed down, Pitfall would go BW and when not pressed, it will be in color.

 

Once that is confirmed than you can start to isolate to just the 7800 and color side of things. 

[Paul Westphal]

I have seen so many issues with the UAV install, I have been hesitant to put one in my 48k 400. If anyone has any foolproof instructions for such, I'd be appreciative.

Edited February 21 by Paul Westphal

[+DrVenkman]

42 minutes ago, Paul Westphal said:

I have seen so many issues with the UAV install, I have been hesitant to put one in my 48k 400. If anyone has any foolproof instructions for such, I'd be appreciative.

There are two threads in the A8 forum about the UAV, both started by @Bryan The first is for the original production Rev C version, and then a separate thread for the improved Rev D. Both of them are filled with info about installing in any number of machines including 400's and 800's. However, I think at this point most 400/800 owners have instead been opting to install a SuperColor board, which incorporates the UAV design into the PCB that replaced the ANTIC/GTIA board in stock machines. Searching the A8 forum for those threads should find them pretty quickly.

[+-^CrossBow^-]

@Nick15 I just got a good look at the picture you posted. Why do you have point to point wiring from the resistors to the UAV mount, and again from the UAV mount to the UAV? The UAV is designed to fit onto the pins on the top side of the mount board for easy soldering into place, and the thicker bottom pins off the mount board are designed to be installed directly to the legs of the resistors so it all goes together into a nice little setup.

 

Now, that said, it is possible that the your mount board is the issue. I've now had at least 4 physically come to me that were done by Brewing Academy where the main IC on it that handles the chroma timing correction, is actually oriented and installed the wrong way around. When that happens, if you are lucky then the color signal from the maria will still happen to pass through enough that the output will work and just basically look the same as it did without the chroma fix in place. Sometimes, if the signal is too weak, then you will get a black and white output. So my guess without seeing more detailed pics, is that the IC on the mount is backwards and causing your issues. Since you already have wiring everywhere, you could remove the mount from the install and just wire up the UAV directly to those resistors and see if you then at least get color and would know the mount board is likely the issue here.

 

I didn't really mention this publicly because I was told by TBA at the time that it was likely just a handful of them that were done this way. Again, I've had at least 4 that I've seen where I had to correct them myself when they were sent to me but even TBA wasn't sure exactly how many might be affected. I still don't think it is that many but something to be aware of.

 

Here is a picture of one of the mount boards from TBA that I received from another modder where the IC was backwards. If you look at the Ti logo you can see it is upside down in this view. Pin 1 in this pic is located in the upper right. But again this isn't the correct orientation for the IC.

 

Here is one of my last revision mount boards where you can see the IC is oriented the other way around and the Ti logo is right side up. In this picture pin 1 is located in the lower left and is the correction orientation for the mount boards. All mount boards I've created and designed have this IC in the same orientation.

 

Attached is also a different PDF guide for installing the UAV in the 7800 with a mount board setup vs the point to point wiring method. This guide has been sent to TBA but not sure if they include links for it or not.

 

 

UAV_Install_A7800_Mnt_Brd.pdf

[Nick15]

10 hours ago, -^CrossBow^- said:

Why do you have point to point wiring from the resistors to the UAV mount, and again from the UAV mount to the UAV?

I opted for point-to-point wiring temporarily to troubleshoot and easily access the UAV and mounting board. The one pictured is actually the second UAV I bought for this project; honestly I wasn't sure if the black-and-white screen was because of a problem with the first UAV I bought or something else, but since the first UAV was already soldered to its mounting board, I wouldn't be able get to the components easily if it was an issue with either board, and I just didn't have the time or energy to try to un-sandwich the two. At least with point-to-point writing, I can quickly access and inspect the UAV and mounting board... which seems to have been be a fortuitous decision if it ends up being an issue with the mounting board itself. In any case, once the troubleshooting is complete, I'll probably just switch back to the first UAV I bought (assuming I can fix that one as well) and use the second one for another Atari model.

 

So yeah, when I get a chance, I'll check to see if that surface IC was installed incorrectly or not... if it was, I'll put my soldering iron down, flip it and reverse it.

 

...

 

On 2/17/2024 at 8:34 PM, -^CrossBow^- said:

@Nick15 If you have a meter, I would put it in resistance mode and verify that you getting changes in readings on the 7800 color trimmer when you move it about. To confirm if the pause button is an issue or not, use the game pitfall as it has a dedicated BW mode and color modes. You stated you have color working in 2600 games so when pressed down, Pitfall would go BW and when not pressed, it will be in color.

 

Once that is confirmed than you can start to isolate to just the 7800 and color side of things. 

I'll take a look at that if it ends up that the mounting board WAS built correctly, but I did test the resistance of R10-R16 beforehand and they all appeared to provide the correct values. I also did a continuity test on the Pause/BW button and it was functioning properly as well. I also have a copy of Pitfall for 2600 so I can test that out as well.

 

Thanks for both suggestions @-^CrossBow^-!!

 

 ...

 

On 2/21/2024 at 2:39 PM, Paul Westphal said:

I have seen so many issues with the UAV install, I have been hesitant to put one in my 48k 400. If anyone has any foolproof instructions for such, I'd be appreciative.

Truth be told, I've bought like three or four other UAVs and this is the only issue I've ever had with the UAV. Even then it appears to be a matter of the mounting board versus the UAV itself. I have one in my 800XL and it works like a charm! The instructions that came with it from The Brewing Academy worked fine for me.

 

[Nick15]

Alas, the flipped IC was not the case... both boards have the IC installed right-way-up:

 

 

I'll try going straight into the UAV and bypassing the mounting board next, as well as do that multimeter check you suggested. I was hoping to avoid bypassing the mounting board because I wanted to use the audio side as well, but c'est la vie...

 

And if there are any other details you'd like me to check for you, I'm all ears.

Edited February 23 by Nick15

[+-^CrossBow^-]

Are you not getting any color output at all from both 2600 and 7800 games? I should have asked that in the beginning.

 

And I've installed easily about 200 UAVs into various Atari systems over the past 6+ years and only encountered 3 actual bad UAVs in that time. 2 I was able to fix myself with the 3rd one having a faulty IC on it and I keep it on hand as my physical demo UAV board for checking where trace connections go etc.

 

And aside from the issue I mentioned with some of the UAV mount boards from TBA having the IC on wrong, those have also been solid both the ones from TBA and the ones I make myself.

 

If connecting a wire direct from the MC output off the Maria back to the UAV doesn't work, then the issue is either the maria itself or unlucky with 2 faulty UAVs. If you haven't done this already, then you might try popping the RF modulator back on to also verify if the Maria or the UAV is the fault here.

 

 

 

[Nick15]

On 2/23/2024 at 9:22 AM, -^CrossBow^- said:

Are you not getting any color output at all from both 2600 and 7800 games? I should have asked that in the beginning.

No worries! I'm definitely getting color from 2600 games, which just added to my confusion. Sometime this weekend I'll try hooking the UAV up only (no mounting board) to see if that has any change in color. I'll provide some pictures of key points as well.

 

On 2/23/2024 at 9:22 AM, -^CrossBow^- said:

If you haven't done this already, then you might try popping the RF modulator back on to also verify if the Maria or the UAV is the fault here.

I'll try that too... like, the RF Modulator worked well enough to show that it was in color when the UAV+mounting board shows B/W, but I'll see what kind of other effects it may have on things. I'll include that in my photo packet later on.

 

On 2/23/2024 at 9:22 AM, -^CrossBow^- said:

And aside from the issue I mentioned with some of the UAV mount boards from TBA having the IC on wrong, those have also been solid both the ones from TBA and the ones I make myself. ... If connecting a wire direct from the MC output off the Maria back to the UAV doesn't work, then the issue is either the maria itself or unlucky with 2 faulty UAVs.

I did buy both UAVs and mounting boards right around the same time, so if they are both bad then they're probably part of the same batch... no knock against the UAVs in that case, these things can happen. I do have other Atari systems with working UAVs so I could compare one another and see if maybe an IC was swapped during their original build. But yeah, the UAVs are great and simple addons which just work, so naturally such a high success rate made my question my own actions first before the quality of the boards, lol 😅

Edited February 24 by Nick15

[Erzak]

I just installed a UAV with the mounting board today, and am having the exact same issue.  I verified that I am getting color in 2600 games.  I expect I will need to unsolder the UAV and mount board in order to check if the chip is oriented correctly?  The pot that's on the UAV is only for S-video color phase, correct?  I've only hooked up composite so far.

[+-^CrossBow^-]

2 hours ago, Erzak said:

I just installed a UAV with the mounting board today, and am having the exact same issue.  I verified that I am getting color in 2600 games.  I expect I will need to unsolder the UAV and mount board in order to check if the chip is oriented correctly?  The pot that's on the UAV is only for S-video color phase, correct?  I've only hooked up composite so far.

The trimmer pot on the UAV is to adjust the color phase for artifact effects. You adjust this using composite output. Depending on the exact type of chip that was used for the 4050, the adjustment will usually get best results with the pot turned either a qtr turn left or right from the middle. I usually load up Tower Toppler using composite to adjust this. If you have Rikki & Vikki, you can adjust it so that the water isn't pea green on composite and will actually be blue again.

 

Also @Erzak if you can remove the mount board and just look at it from the sides, you should be able to look at the 4050 chip to see how it is oriented.

 

BTW...this is why I state in my install guide to press the UAV onto the mount but NOT solder it into place to test everything. You can press down on it with your fingers to get most of the connections you need to at least see video output and some color even if not all of the LUM signals are making good contact just yet. Once you have seen and verified that, then  solder the UAV onto the pins since it is quite a challenge to remove the UAV off the mount once soldered into place.

 

Another thing is to remember to solder +5 and ground to the mount board before soldering it down. If you forget to do this, then just solder +5 and gnd off the UAV pads to make sure everything has power.

 

[+-^CrossBow^-]

@Nick15 and @Erzak , 

 

You should be able to connect a wire directly from the MC test pad I have listed in the install docs near the Maria. Run the other end directly to the Col In pin or via on the UAV. That bypasses the chroma timing fix portion of the mount board. See if you get color that way on 7800 games. If you do, then it does point to some issue on those mount boards you guys have. If that works, you can still use the mount boards for the audio stuff and just leave the color portion bypassed in that case.

 

If that is the case, I might ask one of you to send one of them to me so I can look at it further and see where the issue might be with them? I've only installed a few of the TBA boards and aside from the ones I mentioned having the IC on backwards, they worked as expected. 

 

Now I did have one of client of mine about 5 years ago that I did an UAV install for that complained they were also only getting black and white on the s-video. They sent it back and it was working fine for me on the 3 TVs I had to test it with at the time. I sent it back and they again complained about black and white output. In the end, they tried their 7800 on a different TV and it worked properly. I think their TV was an Emerson or something but that is the only other instance I've heard with a UAV just not being compatible with a particular TV.

 

Another question and if this was answered already i apologize, but what about composite output? Is it black and white on composite output only for 7800 games also? 

 

Below is a quick diagram I just did to check if you have continuity between the points shown... This is my newer revision that TBA doesn't have but there isn't any difference in the chroma timing side of things.

 

Orange is connectivity from the MC tap point off the main board and from the color output directly off the Maria to pin 9 on the IC. There is a via next to this as well that you can test but it is usually covered in solder mask. (This is the initial input of the color signals from the Maria into the IC)

Red is connectivity from pin 15 of the IC to the Co In pin on the mount board and the UAV when attached. (This is the final color output signal that the UAV then processes from)

Yellow is Pin 3 and Pin 4 on the IC. Both of those should show continuity between them. (On my very first revision boards, I had the trace missing between them resulting in a black and white image. However, TBA was provided corrected plans only that didn't have this defect. Therefore that issue should never be present on TBA boards)

 

 

[Erzak]

I will check stuff as soon as I can.  Sadly, work interferes   I have only tried composite video so far, need to dig out a S-video cable from the attic to try that out.  Does the chroma timing circuit affect composite video at all?  If not, then yes, I've botched a connection someplace.

 

I did check a couple of other things quickly:

    - RF output still works, had color for 7800.  Well, had color with the boot screen and menu using my 7800GD cartridge.  Didn't try a 2600 or 7800 cartridge yet.

    - The AV output on my 7800GD cartridge is not working now.  This is a bit confusing to me, but this also makes me think I've botched a connection someplace.

    - A 2600 cartridge has color thru the UAV composite video output, didn't try a 7800 cartridge yet.

    - A 7800 ROM on the 7800GD is B&W thru the UAV composite video output.  Didn't try a 2600 ROM yet.

[+-^CrossBow^-]

The UAV doesn't effect the 7800GD output at all. I use a 7800GD with my UAV 7800 all the time without issues and in fact use both the 7800GD and other cartridges on 7800s I've installed both the mount and UAV into and never had an issue there.

 

No color from only 7800 games on both composite and s-video indicates that the color signal from the maria either isn't making it to the UAV or there is an issue in the UAV in processing it. I've not had that exact issue with a UAV before as the issues I had in the past were just no output at all from the UAV. Those were corrected by applying some fresh heat to all the pins on the ICs of the UAV as apparently there were one or more cold joints on the UAV. I did have a UAV that wasn't producing color from 2600 games. Found out that UAV had a flaw in the trace from the TCol pin back to the IC where the connection wasn't present. I corrected that one using a small piece of clipped lead that I soldered to jump that faulty trace within that particular UAV board.

 

The only other issue I've had aside from what I've listed on the UAVs is the one that has a faulty IC on it. It does produce output and color, but half of the screen is darker in brightness vs the other half. That is the one I use as a physical dummy board for verifying where things are connected within the UAV etc..

 

Pretty sure that if you aren't getting color from composite output then s-video isn't going to change that. So really if the points I've listed check out on the mount boards, then there are only 3 possibilities at this point:

 

1. is that Maria color output isn't working. But as I stated you can bypass the mount board chroma fix circuit by attaching from the Maria color output directly off the test pad/via near it directly to the co in on the UAV. If that works...then it leaves us with...

2. that there is an issue with the mount boards that TBA has sold. If the continuity checks out, then it could be faulty ICs or a faulty trace under the ICs on the mount boards. I don't know where TBA sourced their parts from, but I buy all the parts I use on mine directly from Mouser and even have a BOM project list setup with Mouser so I can quickly order everything needed for them.

3. If no color output comes from the UAV even with the bypass, then the issue is something faulty with the UAVs themselves in regards to the portion that handles the maria color signal.

 

We can already rule out #1 since you stated you have 7800 games working in color from the RF output. So it has to either be an issue with the mount boards or the UAVs.

 

 

 

 

[Erzak]

Any idea why my 7800GD AV output would not be working?  It worked previously.  If I messed up a connection, could that screw up the signal going to the 7800GS somehow?  I assume that it is intercepting the video signal somehow.

 

I think my first step will be to remove the mount board from my 7800, then remove the UAV from it, unless you suggest a different flow.

[+-^CrossBow^-]

49 minutes ago, Erzak said:

Any idea why my 7800GD AV output would not be working?  It worked previously.  If I messed up a connection, could that screw up the signal going to the 7800GS somehow?  I assume that it is intercepting the video signal somehow.

 

I think my first step will be to remove the mount board from my 7800, then remove the UAV from it, unless you suggest a different flow.

Well for now just get the console back to stock condition first. So remove the mount board and go from there.

 

The 7800GD emulates the picture output through the AV out on  the catridge. The only data on the cartridge port to the best of my knowledge is just the cartridge data and audio input. There isn't any video in/out on the cartridge port of the 7800. So I don't have any immediate ideas on the 7800GD output not working but the UAV wouldn't have anything to do with that. Not sure what cable you are using with your 7800GD but I have the 1st release of the cartridge an it only works using a Rad2x or my HDRetrovision cables. It doesn't really work at all through my OSSC setup back to my TV so I can only use cables that aren't part of that AV mix in my game room. I don't use the AV out that much from my 7800GD as a result.

[+-^CrossBow^-]

@Nick15 & @Erzak any updates on this?

 

 

[Erzak]

2 hours ago, -^CrossBow^- said:

@Nick15 & @Erzak any updates on this?

 

 

I've had zero free-time this week, but I plan to get back to it this weekend.

[Erzak]

I did a bit of experimenting and got these results, using my 7800GD multicart and a couple of regular cartridges:

 

I'll bust out the soldering iron and solder wick tomorrow and check/clean-up connections, and then remove the mount board if I don't get it working properly.

[+-^CrossBow^-]

28 minutes ago, Erzak said:

I'll bust out the soldering iron and solder wick tomorrow and check/clean-up connections, and then remove the mount board if I don't get it working properly.

You don't have to remove the mount to bypass the chroma fix circuit of the mount. just run a wire from the MC connection off the mount back to the Co In pin on the output side of the UAV. That will at least let me know if the mount board is the issue. If so, I might ask that you send it to me so I can look it over and see what might be going on. Again, the boards I've made myself have never had any issues like this that weren't due to some error when assembling them. 

 

If I can see what is up with these TBA boards then I can present that info to TBA to see about ways they can correct for it going forward. I do think the issue is either something strange with the ICs used or maybe they got in a batch with a bad trace in the routing under the IC causing the signal to be broken before getting to the UAV.

 

[Erzak]

Okay, running a wire from MC to Co In fixed it, now have color in 7800 games thru composite video out.  I will remove the mount board and see if I can tell if the IC is in backwards, etc.  Let me know other things to look for or check.  If you want me to send it to me, depending on what I find, we can do that.

[+-^CrossBow^-]

1 hour ago, Erzak said:

Okay, running a wire from MC to Co In fixed it, now have color in 7800 games thru composite video out.  I will remove the mount board and see if I can tell if the IC is in backwards, etc.  Let me know other things to look for or check.  If you want me to send it to me, depending on what I find, we can do that.

Yes, depending on where you are located it shouldn't cost that much to send in one of these. just have to put some foam around the pins so they don't get bent in the process. I do suspect there has to be something up with  those boards from TBA because I actually have a small sony PVM (CVBS and svid only), that works great with it, an older 4:3 LCD with a dedicated s-video and composite that also works, my Extron setup in the game room has no issues with it, and even an old JVC late 90s CRT in a spare room I sometimes use for color calibrations works just fine with it. So there has got to be some oddness with those boards and if I can identify it, I'm sure I can let TBA know and see if they can contact those that have bought them. Pretty sure I've seen folks sell already done 7800s using the TBA mounts in the past without issue, so this has to be something new.

 

Send me a PM so we can get something together here.

 

[Erzak]

I got the mount board off the main board.  I can't see the orientation of the IC with the UAV on it.  I've got a de-soldering pump packed away someplace, so will dig that out, tomorrow likely, and remove the UAV.  I did verify that the 7800GD AV out is working by trying a different TV.  For some reason, it doesn't work with the TV in my garage.

[Spudster]

On 2/22/2024 at 7:27 AM, -^CrossBow^- said:

@Nick15 I just got a good look at the picture you posted. Why do you have point to point wiring from the resistors to the UAV mount, and again from the UAV mount to the UAV? The UAV is designed to fit onto the pins on the top side of the mount board for easy soldering into place, and the thicker bottom pins off the mount board are designed to be installed directly to the legs of the resistors so it all goes together into a nice little setup.

 

Now, that said, it is possible that the your mount board is the issue. I've now had at least 4 physically come to me that were done by Brewing Academy where the main IC on it that handles the chroma timing correction, is actually oriented and installed the wrong way around. When that happens, if you are lucky then the color signal from the maria will still happen to pass through enough that the output will work and just basically look the same as it did without the chroma fix in place. Sometimes, if the signal is too weak, then you will get a black and white output. So my guess without seeing more detailed pics, is that the IC on the mount is backwards and causing your issues. Since you already have wiring everywhere, you could remove the mount from the install and just wire up the UAV directly to those resistors and see if you then at least get color and would know the mount board is likely the issue here.

 

I didn't really mention this publicly because I was told by TBA at the time that it was likely just a handful of them that were done this way. Again, I've had at least 4 that I've seen where I had to correct them myself when they were sent to me but even TBA wasn't sure exactly how many might be affected. I still don't think it is that many but something to be aware of.

 

Here is a picture of one of the mount boards from TBA that I received from another modder where the IC was backwards. If you look at the Ti logo you can see it is upside down in this view. Pin 1 in this pic is located in the upper right. But again this isn't the correct orientation for the IC.

 

Here is one of my last revision mount boards where you can see the IC is oriented the other way around and the Ti logo is right side up. In this picture pin 1 is located in the lower left and is the correction orientation for the mount boards. All mount boards I've created and designed have this IC in the same orientation.

 

Attached is also a different PDF guide for installing the UAV in the 7800 with a mount board setup vs the point to point wiring method. This guide has been sent to TBA but not sure if they include links for it or not.

 

 

UAV_Install_A7800_Mnt_Brd.pdf 3.15 MB · 8 downloads

Ugh, never mind. Couldn't see the dot clearly due to the sloppy flux.

Edited March 5 by Spudster
I'm an idiot.

[+-^CrossBow^-]

48 minutes ago, Spudster said:

Ugh, never mind. Couldn't see the dot clearly due to the sloppy flux.

If that is your TBA provided mount board, then the IC is correct. For some odd reason the footprint for that IC that Ti provides for PCB design programs, has that large square off pin 10. That is marking one of the first input gates to the IC and is NOT for pin 1. There is actually a Dot that I added on the PCB board for pin1, but it gets covered up once you install the IC. That one above, looks like it might need to be checked for any shorts between those pins. Although a short on pin 3 and pin 4 on the IC is normal and expected.