Dead 600 XL with upgrades

[TGB1718]

Something is pulling the 5V down to 4.2V, this means something must be getting warm, you've already checked

the chips, I know it's a long shot, but try the larger electrolytic capacitors, see if any get warm, they should be 

just room temp.

 

Whatever it is, it's not a dead short, just have a feel around everywhere, resistors, diodes etc.

 

btw. wasn't being "mean" with my previous comments, just hard to comprehend how someone could do

such a Frankenstein job on a lovely machine.

Edited March 20, 2021 by TGB1718

[archeocomp]

I would also measure voltage at the power DIN connector. Just to rule out the switch.

[mimo]

Looks like a good candidate to rip all those horrible mods out , get it working and then do the mods again correctly

[Paul Westphal]

10 hours ago, flashjazzcat said:

Why the pick off points on the PBI contacts and the immensely heavy wire?

It's all I had at the time. It's a very old picture I use for reference.

[+kheller2]

10 hours ago, flashjazzcat said:

Why the pick off points on the PBI contacts and the immensely heavy wire?

Several of the original 600XL mods used the PBI to pickup the lines needed for the RAM addressing.  Unlike my somewhat attractive mod.  ?

 

 

[flashjazzcat]

1 minute ago, kheller2 said:

Several of the original 600XL mods used the PBI to pickup the lines needed for the RAM addressing.  Unlike my somewhat attractive mod.

Strange. The vias are far closer, but if the instructions described things that way, that certainly explains it.

[+kheller2]

I haven't had enough coffee yet, but I'm trying to understand what is being tapped or bypassed with the center RF jack (I can't tell if the center line is cut and re-wired or just joined to it).  Also, for SVideo, is there enough lines there and video components?  Maybe Composite...  I'm not sure I would go ripping it all out, but certainly it needs to be tidied, and never jostled.

 

The voltage drop is the big concern.  Something isn't right, maybe start by pulling all the chips out and checking the voltage when turned on, then start putting them back in.

[BillC]

8 hours ago, bfollowell said:

you are still going to need a Basic chip later, assuming you're able to revive this machine.

I did also mention that this PCB version is capable using a 2764 EPROM containing BASIC, the converter is already built-in to the PCB.

[_The Doctor__]

rf out jack was repurposed for audio and another rca placed nearby... left and right out for stereo pokey... I think that's been pointed out though. lol by me

[leech]

56 minutes ago, _The Doctor__ said:

rf out jack was repurposed for audio and another rca placed nearby... left and right out for stereo pokey... I think that's been pointed out though. lol by me

Yeah.  This thing is a mess.  Like someone almost knew what they were doing, but were afraid to take a direct route and wanted instead to take the back roads...

[Dinadan67]

12 hours ago, Sugarland said:

After checking the IC's, I would seriously consider removing all that crap and put it back to stock.

Really? That would mean loosing stereo and s-video. I would try to get the machine working.

[manterola]

Beside the execution, the final result is quite nice, in the sense that you got a 600XL with a standard mini din S-video connector, standard audio RCA stereo output and 64KB machine, with a beautiful exterior and Chelco based interior. If I were you I would try to fix it and once everything is working (and hidden) it will be a quite great machine.

 

Edited March 20, 2021 by manterola

[+kheller2]

Have you tried connecting the L and R audio lines up to a receiver or something to see if you hear the normal Atari boot fart?

 

[Sugarland]

On 3/20/2021 at 4:06 PM, Dinadan67 said:

Really? That would mean loosing stereo and s-video. I would try to get the machine working.

 

He needs to isolate the malfunction.  Your argument is a non-sequitor. He can add stereo and s-video back once it's working.

 

Edited March 24, 2021 by Sugarland

[gobo]

Had some time today to try out a few things on the 600XL. First thing I did was hook up the audio lines to a speaker like kheller2 said. When I tried the new extra audio connection I got nothing but when I attached the ex-RF port I got a beautiful Atari fart. Music to my ears and no smell.;) I had originally tried to hook it up from there to a TV's RF. Next I tried an S-Video to HDMI adapter that I borrowed and viola I had a picture too. So the RF works as audio, the other "audio" port does nothing unless I'm missing something and S-Video produces a picture.  Memory is 64k and tests fine. I'm very happy and surprised it's working at all with no changes. The only problem now is that the video output is off. The colors are wrong and there are vertical bars. When I tried to set the background to a shade of grey, the bars disappear and the picture is very smooth. Would the next move be to swap out the GTIA. Was trying to avoid  dismantling my 800XL. Would it be hard to dismantle the s-video hack (and use a more modern video solution)?

 

 

[_The Doctor__]

The other audio jack won't make a sound until you use a program in stereo mode. At that point the software will start using the second pokey and then you will get sounds. You may have to select stereo in a menu screen on some of the stereo titles also... may

Edited March 24, 2021 by _The Doctor__

[R.Cade]

Adjust the video timing pot and see if you get the right colors then...

 

The vertical lines are unfortunately normal. There are a dozen "hacks" to improve it on the forums here.

 

 

 

Edited March 24, 2021 by R.Cade

[+kheller2]

From what I gather you have no RF out anymore, the RF jack was repurposed for the onboard Pokey audio.  The other RCA jack is for the 2nd pokey.  I would suggest just installing a UAV to make your video much better.  You could also re-hookup the RF jack inside the box and see if that gives you a better pic.

[_The Doctor__]

30 minutes ago, kheller2 said:

From what I gather you have no RF out anymore, the RF jack was repurposed for the onboard Pokey audio.  The other RCA jack is for the 2nd pokey.  I would suggest just installing a UAV to make your video much better.  You could also re-hookup the RF jack inside the box and see if that gives you a better pic.

that was the analysis as of the 5th post

UAV would help and you could put rf back as well as add a proper audio jack pair to avoid future confusions

[mimo]

Cheap S-video to hdmi adapters are a real mixed bag from crap to won't work at all in my experience.

I'd definitely try at least UAV mod and playing with the colour pot . Best would be a sophia2 if you are going to be using a hdmi TV 

[gobo]

Good news everyone! I adjusted the Color POT and it looks pretty good. Still has some bars but not too bad. Might be able to blend them out by adjusting the sharpness of the monitor. There are a few artifacts shown when I put up all 256 colors but so far I haven't noticed it anywhere else. I think a UAV is in the future but for now I'm OK with the results. Heck at this point I'm not even sure if there was ever problem with it turning on because when I plugged it in today using the same 3 outlet extension cord (and after its been powering on fine) it didn't power on. At first I thought WTH but I switched it to another outlet on the same cord and it works fine. Would not have been happy ripping it apart and later finding out it was that! So basically it looks like that messy looking upgrade was working all along, all it needed was the POT to be adjusted. I'm a little embarrassed actually but I learned something along the way! And thanks for all of the help.

Edited March 26, 2021 by gobo

[+Nezgar]

Now that the main issues have been figured out, you can do the mod to allow a 2764 EPROM to replace the BASIC ROM as @BillC mentioned. If you need a chip I'd be happy to mail you one programmed with a socket.

 

Other option is not modifying the board, and inserting an adapter like this, which can even let you have up to 8 switchable BASIC ROM's

https://store.go4retro.com/2364-adapter/