Atari 7800 troubleshooting and repair

Рет қаралды 6,863

Жыл бұрын

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Trying to fix the Atari 7800 sent over by Visi from the Netherlands. This turned out to be quite the troubleshooting journey.
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🛠 Tools and kit: www.patreon.com/posts/tools-and-kit-77570017
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😎 Ad-free, early access: www.patreon.com/theretrochannel
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7800 schematics: atariage.com/7800/archives/schematics_pal/
7800 troubleshooting guide and theory of ops: forums.atariage.com/topic/216763-7800-theory-of-ops-ts-guide/
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🎞
0:00 Intro
3:10 Power on behaviour
6:12 Board inspection
10:26 The other 7800
13:26 ROMs
19:31 Jumpers
23:34 Cartridge selection logic
29:05 Chip select oddity
32:20 It's what?
36:28 Repair or replace?
38:56 Fixed, almost...
40:41 Fixed, really!
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Thanks for watching!

Пікірлер: 39

@ferndog1461 7 ай бұрын

This is REAL TROUBLESHOOTING. Thank you , mate.

@alpergedik3650 Жыл бұрын

High quality content from a guy who knows what he's doing. I'm not exactly a "retro geek" but his channel still amazes me. Keep it up please.

@bitoxic Жыл бұрын

Visih has been very generous to you lately! 😄👍

@br33ch Жыл бұрын

Gotta love the final step in that flowchart.

@ChadDoebelin Жыл бұрын

i'm proud of you for sticking it all the way through instead of smashing it with a hammer and drop kicking it as suggested in the repair flow.

@JoeBurnett Жыл бұрын

Great video! Thanks for letting us accompany you on your troubleshooting journey. Don’t worry about “assuming” the easiest stuff to fix works - it happens to the best of us AND we would have never got to watch this if you hadn’t.

@jandjrandr 5 ай бұрын

Excellent work on this. Great work root causing this. I suspected the same things as you did at first, so don't feel bad that you took a wrong turn, as I would have done the same. You did get there and that is what counts.

@johnyoder9302 9 ай бұрын

Hi, I just took and made an adapter so I could use an Atari 2600 power supply instead of the 7800-power supply, and it still works great to this day. Don't remember where I foraged the female end from, but soldered it to the board, then used hot glue to keep it in place.

@RetroEvilHunk341 Жыл бұрын

Very cool never got to have Atari 7800 just had 2600 as a kid 😊😊

@ctchich4469 Жыл бұрын

There is always a lesson to learn from every fix even if it is frustrating as all hell

@eto6197 Жыл бұрын

I definitely could feel your pain when you recognised that it's just the port.

@Colin_Ames Жыл бұрын

That was interesting. I would never have suspected the edge connector pins. Great diagnostics.

@gabrieldesantelmo Жыл бұрын

Amazing problem solving skills, Mark. You are a genius! Great video, I loved it.

@TheRetroChannel Жыл бұрын

Thanks. Although genius might be a stretch 😄

@superangrybrit 10 ай бұрын

Good video! 👍

@cryxli 11 ай бұрын

Everyone tinkering with retro hardware tells you to give it a thorough visual inspection first. And noone does it. Me included. Reading a board and inspecting connectors often gives you a first clue on what is going on with a system.

@robbyxp1 Жыл бұрын

The cartridge port.. which was the first thing I said, but I thought its was going to be the dirt in it which would stop it selecting properly. Just goes to show you that visual inspection is key.

@glonch Жыл бұрын

What a trip... I felt your pain... lol. Glad you got it working

@MoreFunMakingIt Жыл бұрын

Well that took an unexpected turn! So obvious after the fact 😂 Still a lot of useful info in the run up to the facepalm moment. Lovely journey, great video.

@TheRetroChannel Жыл бұрын

It's all about the journey, at least that's what I kept saying to myself in this one

@wilfredpayne433 4 ай бұрын

Well i know where im sending my consoles for repair...adrians digital basement 😂 im kidding...he doesn't work on consoles 🤣 I subscribed.

@Zeem4 Жыл бұрын

I wonder if someone who didn't know what they were doing had bent those pins inwards, trying to improve the connection with the cartridges by increasing the pressure on the contacts. This is the kind of thing that would work well on a ZX81 RAM pack, Spectrum joystick interface or similar, when the socket's on the external device.

@bubbles581 Жыл бұрын

i never knew the 7800 had asteroids built in. I had one for years as a kid!

@TheRetroChannel Жыл бұрын

Only on the PAL versions, NTSC did not have asteroids built in

@ovalteen4404 Жыл бұрын

I wonder if the 36-pin connector could be replaced by a normal size connector sitting on top of a couple of 36-pin female headers, or a long enough line of chip sockets? Would be janky, but might work. The edge connectors can be ordered with long pins, but you're probably a victim of the middle-suppliers who don't stock them. If you could order direct from TE/Amphenol/Conglomerate, you could probably find exactly what you want. Though a connector that already comes with keys installed would likely require a minimum order.

@TRONMAGNUM2099 Жыл бұрын

This solve reminded me of the Occam's razor lesson we were taught in tech school. Look for the simple solutions first. Glad you got it figured out, though. I know you pulled your hair for a little while. Was wondering if you can try reading the 2600 roms in the mini pro? If they are indeed the problem and not some other physical problem. I was thinking maybe you could repurpose a cart and make a multicart? there are several on PCBway. I'm lazy and bought an unocart. You could do that, but I know how you like to make it and tweak it to add improvements.

@TheRetroChannel Жыл бұрын

Yeah I think the ROMs in the 2600 carts are dead. I opened them up and three of them only contain a mask ROM, and the fourth has extra logic (I assume for bank switching). The problem is even if I wanted to replace the ROMs, there is not enough room in the cart to fit a 24 to 28 pin adaptor. Also Atari used an active high signal for the chip select, where as EPROMs use an active low, so I'd need to put in an inverter gate as well. I'll have a look at multicart options, see what is out there

@lynnmakes Жыл бұрын

So to make a note on the Activision carts... the 7800 "collar" is tighter than on the 2600, and the Activision cart shells are actually larger than the 2600 cart shells, which means they don't fit inside the collar well and don't make good contact. My 7800 I actually deliberately cracked two opposite corners of the collar to help Activision carts fit.

@davidgeltz7604 10 ай бұрын

I was yelling at the computer for you to take off the cover of the cartage port from the beginning ( that is where I would have started).....

@JVHShack Жыл бұрын

I'm not sure how, but I figured out what the issue was at the very beginning. I'm not going to say what it was here, though.

@morantaylor Жыл бұрын

1st 7800 is newer the date codes on chips are 1990 while the second is 1989. To read in the programmer you should be able to turn off "pin detect" checkbox option to read the fixed rom. The fixed ROM won't have a program pin for a start so it will fail detection. The 2600 cartridges probably have logic in them to allow bank switching to get around rom address limit similar to the C64 the jelly bean logic may have died causing the cartridge to draw a lot of current.

@TheRetroChannel Жыл бұрын

I tried turning off pin detect off camera but it still refused to read. Going to take another look at it soon. As for the 2600 carts, one of them has a logic IC inside but all of them seem to have faulty mask ROMs

@LeeLayland 10 ай бұрын

Search for wire wrap connectors

@ChrisShadowens Жыл бұрын

It's weird that whole stack of 2600 carts is bad. Back when I was collecting of the 250+ 2600 carts I had only 1 ever died on me, Atari's "Surround". Overall, they're fairly bomb-proof. Did you try them again after you sorted out the cartridge port pins? One of the few 2600 games I recall being incompatible with the 7800 was Activision's "Robot Tank" so I don't think that's the issue.

@TheRetroChannel Жыл бұрын

Yeah tried them again after sorting the cart port pins. Also gave the cartridges a good clean but still no go. I think they all must have come with one of the 2600s I bought from fleabay. My guess is the seller knew they were faulty and threw them in as 'untested'

@ChrisShadowens Жыл бұрын

@@TheRetroChannel Well that's a shame! I guess with a bit of cleaning they make for decent shelf art if nothing else.