UAV color problem after installing and using some 2600 cartridges

[raymondjiii]

Hi, I was hoping to get some advice on what I could possibly try to resolve this issue:

 

I have a new UAV installed on a 7800. I used the following diagram exactly from CrossBow's instructions:

 

 

In 2600 mode, the colors are too dark for Frogger. When the frog hits the street you can barely see him (and also barely see the 2nd to top row of cars). I have adjusted the 2600 adjustment and I have the colors to be as close to what I think they should be. 7800 mode games seem okay although I have not tried them all. Other 2600 games are good, Activision Tennis for example. Anyone experience anything like this? I keep thinking that maybe there is some component that could possibly be replaced - what component I don't know.

 

I do have another 7800 console with UAV and I am going to open that one up to see if anything is different as Frogger works just fine on that unit. I know some 7800's have a chip on the right hand side and some boards do not (different revisions of the board.) I'm not saying that is the issue here but that's the only obvious difference I have seen so far.

 

(I have no RF device to test on.)

 

Thank you,

Ray

Edited March 27, 2023 by raymondjiii
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[+-^CrossBow^-]

@raymondjiii  Not sure if you saw my last answer to your PMs on this or not, but we really need to see some pictures describing what is being shown to get a better idea on what might be happening. 

 

I also answered your questions about the extra timing circuit which is part of what that extra chip on the right center of the console was specifically for. Again, that doesn't really impact the visual output as a whole for 2600 games and has more to do with the timing of the video for the 2600 games and was later removed in many 7800s with a zero ohm resistor being used to bypass that section with the chip removed.

 

 

[raymondjiii]

Just following up here on this thread in case anyone runs into a problem in the future and wants to see what I am experiencing. I re-checked the connections and they are correct from the resistor ladder to the UAV board as well as used a continuity tester on all connections. I'll try to give each point a new solder connection and try to rule that out as well.

 

Frogger with blue border and blue frog

 

Frogger with green border and green frog.

 

I adjusted the 2600 potentiometer to best colors I could get, no setting turns the border green though.

 

[+DrVenkman]

Do you have anything to run a 2600 diagnostic cart on? (Harmony Cart for instance) If so, pull up a color test image that shows all the expected colors. It would help determine if there's something amiss with one of the UAV LUM connections or signal paths on the 7800.

 

Was the 7800 producing expected colors on 2600 games before it was modded? 

[+-^CrossBow^-]

2 minutes ago, DrVenkman said:

Do you have anything to run a 2600 diagnostic cart on? (Harmony Cart for instance) If so, pull up a color test image that shows all the expected colors. It would help determine if there's something amiss with one of the UAV LUM connections or signal paths on the 7800.

 

Was the 7800 producing expected colors on 2600 games before it was modded? 

I thought about this, but in his PM to me on this, he states that 7800 games looked correct. So if it were a bad LUM connection point on the UAV I would think 7800 games would be equally effected. But what is odd is that in his pic it seems some green might still be present given the color of the logs there (They do tend to look green from a UAV). I'm wondering if it isn't the TIA itself here? 

 

 

[+DrVenkman]

3 minutes ago, -^CrossBow^- said:

I'm wondering if it isn't the TIA itself here?

That was where I was going with the last question I asked. 

[+-^CrossBow^-]

29 minutes ago, DrVenkman said:

That was where I was going with the last question I asked. 

We are on the same line of thinking then.

 

[+DrVenkman]

25 minutes ago, -^CrossBow^- said:

We are on the same line of thinking then.

 

If the machine is socketed, could also be a bad connection to one of TIA's LUM lines too, I suppose. But removing the chip to examine the socket would reveal most of those kinds of issues. Too bad TIA's are getting so expensive these days. Would be good if one of the FPGA boffins was making and selling pin-compatible replacements. 

[+-^CrossBow^-]

18 minutes ago, DrVenkman said:

If the machine is socketed, could also be a bad connection to one of TIA's LUM lines too, I suppose. But removing the chip to examine the socket would reveal most of those kinds of issues. Too bad TIA's are getting so expensive these days. Would be good if one of the FPGA boffins was making and selling pin-compatible replacements. 

If it is the one he sent me a pic of in PMs...then sadly the TIA is soldered directly to the main board. And yes, the TIAs are now more expensive from Best than POKEYs at this point.

 

[raymondjiii]

Couldn't test it prior since I have no RF to use. I'm going to try another UAV tonight. That should narrow it down.

[raymondjiii]

3 hours ago, DrVenkman said:

Do you have anything to run a 2600 diagnostic cart on? (Harmony Cart for instance) If so, pull up a color test image that shows all the expected colors. It would help determine if there's something amiss with one of the UAV LUM connections or signal paths on the 7800.

 

Was the 7800 producing expected colors on 2600 games before it was modded? 

The verdict is in....new UAV board installed tonight works. Frogger is green and the final test....Activision Tennis - green court. Either something I did with the soldering iron or bad UAV board.

 

@DrVenkman I am not familiar with the Harmony cartridge. I've seen the original diagnostic cartridge...is the Harmony cartridge that I've seen with the sd-ram slots ???  I would not mind getting of those if I can find one.

 

Thanks for your help.

[+DrVenkman]

4 minutes ago, raymondjiii said:

I am not familiar with the Harmony cartridge.

The Harmony is one of now several solutions available to run 2600 game binaries on original hardware. Only works with 2600 compatible files, however given the split-nature of the 7800 and your 2600 game-specific video issue, it would be a useful way to characterize the video issue if necessary.

 

There are a few different 7800 solutions as well (for .a78 files), of varying compatibility and availability but if you scan through this forum or do a search, you'll find all the info on each of them. 

[raymondjiii]

19 minutes ago, DrVenkman said:

The Harmony is one of now several solutions available to run 2600 game binaries on original hardware. Only works with 2600 compatible files, however given the split-nature of the 7800 and your 2600 game-specific video issue, it would be a useful way to characterize the video issue if necessary.

 

There are a few different 7800 solutions as well (for .a78 files), of varying compatibility and availability but if you scan through this forum or do a search, you'll find all the info on each of them. 

Can the ROM's from atarimania be put on the Harmony? Or are those strictly for ee-proms?

[+DrVenkman]

59 minutes ago, raymondjiii said:

Can the ROM's from atarimania be put on the Harmony? Or are those strictly for ee-proms?

Indeed. This link has all you need. When fully expanded, this archive even has a set of folders you can copy straight to the SD card, containing the roms sorted alphabetically by name, and alphabetically by publisher.

 

[raymondjiii]

11 hours ago, DrVenkman said:

Indeed. This link has all you need. When fully expanded, this archive even has a set of folders you can copy straight to the SD card, containing the roms sorted alphabetically by name, and alphabetically by publisher.

 

Thank you. I bought one of the Harmony cartridges at harmony.atariage last night. Do you if these devices have a limit on the SD size? I'd like to have my SD card ready to go when it arrives.

[+-^CrossBow^-]

37 minutes ago, raymondjiii said:

Thank you. I bought one of the Harmony cartridges at harmony.atariage last night. Do you if these devices have a limit on the SD size? I'd like to have my SD card ready to go when it arrives.

I'm sure there is a limit but I'm not aware of what that is right off hand. I only have like an older 2GB in my Harmony as mine came with one when I bought it many years ago. It only had a few files on it of course so it could be tested out of the box, but I never did replace the SD card it came with. 

 

So a replacement UAV took care of the issue? That is good since the UAV is cheaper than a replacement TIA. It is also possible that UAV can be brought back to life. It is likely one or a few pins on one of the ICs might not be making a good connection. I've fixed 2 of the 3 bad UAVs I've gotten in over the years by using some flux and fresh heat applied to the SMD IC legs.

[raymondjiii]

19 minutes ago, -^CrossBow^- said:

I'm sure there is a limit but I'm not aware of what that is right off hand. I only have like an older 2GB in my Harmony as mine came with one when I bought it many years ago. It only had a few files on it of course so it could be tested out of the box, but I never did replace the SD card it came with. 

 

So a replacement UAV took care of the issue? That is good since the UAV is cheaper than a replacement TIA. It is also possible that UAV can be brought back to life. It is likely one or a few pins on one of the ICs might not be making a good connection. I've fixed 2 of the 3 bad UAVs I've gotten in over the years by using some flux and fresh heat applied to the SMD IC legs.

Has anyone ever purchased those 2600 chip replacement kits from eBay? Seller is in Brazil, decent eBay score. Just wondering for future needs.

[+x=usr(1536)]

1 hour ago, raymondjiii said:

Do you if these devices have a limit on the SD size?

I've run up to a 32GB card in mine without any issues.

 

[raymondjiii]

 Possibly a different thread but it's same console in question here....what do people use to clean the contacts with inside the cartridge slot? I was thinking Deoxit D5 ?

[+-^CrossBow^-]

24 minutes ago, raymondjiii said:

 Possibly a different thread but it's same console in question here....what do people use to clean the contacts with inside the cartridge slot? I was thinking Deoxit D5 ?

I just use an electronics contact cleaner I buy locally. I just spritz a little directly into the cartridge port. I then use a section of a fake credit card cut to fit the slot with rounded corners. I wrap it in an old t-shirt and slot that in and out of the port several times. I then move the cut portion of the credit card to a dry section of the t-shirt, spray a little IPA directly on the shirt and card combo and run that through the slot quite a few more times until everything comes out looking clean. 

[raymondjiii]

47 minutes ago, -^CrossBow^- said:

I just use an electronics contact cleaner I buy locally. I just spritz a little directly into the cartridge port. I then use a section of a fake credit card cut to fit the slot with rounded corners. I wrap it in an old t-shirt and slot that in and out of the port several times. I then move the cut portion of the credit card to a dry section of the t-shirt, spray a little IPA directly on the shirt and card combo and run that through the slot quite a few more times until everything comes out looking clean. 

Check out DeoxIT D5 - especially if you work on other electronics equipment. They have a line of products. Considered by many to be the best.

 

[+-^CrossBow^-]

46 minutes ago, raymondjiii said:

Check out DeoxIT D5 - especially if you work on other electronics equipment. They have a line of products. Considered by many to be the best.

 

Well aware of their stuff, I just refuse to pay their costs and stick with stuff I can get locally that works for me.

 

[+DrVenkman]

I use both, and have for years now. Iso for most purposes including cleaning up flux residue and generally de-griming dirty electronics, Deoxit for stuff with visible oxidation. Fortunately, most Atari stuff used gold-plated contacts so they don't corrode or oxidize. Iso works great to clean that stuff nearly all the time. But for switch contacts, paddle potentiometers, and stuff of that nature, Deoxit is my go-to. And a very tiny bit goes a long way. I think I've bought two cans in the last 10 years and the second one is still mostly full.

 

The only time cleaning with iso didn't work for me when I thought it should have was with a couple of really dirty 2600 carts I bought locally. One cart just didn't work after several cleanings with 92%. I sprayed a dribble of Deoxit on the contacts, then did my usual routine: wet the contacts, insert and remove the cart from the connector several times, allow everything to dry and then test. One shot of Deoxit cleaned off whatever was in those contacts that 3-4 tries of iso didn't take care of. 

Your mileage may vary of course. 

[raymondjiii]

I love DeoxIT D5. It can leave a slight residue, although many people will disagree with that statement. Nothing is better on potentiometers, amplifiers, stereos, guitars, Atari paddles. I used to use Radio Shack's brand and was happy with that until. Interesting that you said "cleaning up flux residue" - most flux brands (depending on the type) claim no cleanup necessary. Other than a little shine added to the board I can't say that I've ever noticed anything, at least longterm. I like the 91 ISO on the entire boards when possible. I opened two Atari CX-22's today and wasn't sure what to put on the shafts. But as I looked at it closer it finally reminded me battery terminals, so I went with the baking power and followed up with a thin coat of DeoxIT D5. One of these CX-22's was my original purchase back in the early 80's. This other unit which is white on the bottom but otherwise the same shape - has a switch for "Joystick" or "Paddle" - I never saw that before, that is a nice feature.