+Andrew Davie Posted October 11, 2020 Share Posted October 11, 2020 Hi All I'm in Australia. I'm trying to diagnose an issue that affects ONLY a PAL 7800 PlusCart. I do not have a 7800 handy. I'm posting here to ask if there is anyone in Oz willing to loan me their 7800 for a few weeks? I would pay postage both ways, of course - and happy to put a security deposit on unit if so required. Thanks A Quote Link to comment Share on other sites More sharing options...
+mksmith Posted October 11, 2020 Share Posted October 11, 2020 I have a spare one (totally untouched) Andrew but no power supply for it unfortunately... Quote Link to comment Share on other sites More sharing options...
+Andrew Davie Posted October 11, 2020 Author Share Posted October 11, 2020 Just now, mksmith said: I have a spare one (totally untouched) Andrew but no power supply for it unfortunately... TY. I don't have any knowledge of what is required, unfortunately. Quote Link to comment Share on other sites More sharing options...
+mksmith Posted October 11, 2020 Share Posted October 11, 2020 If I come across one in the next few weeks I'll get back to you ? Quote Link to comment Share on other sites More sharing options...
+Andrew Davie Posted October 11, 2020 Author Share Posted October 11, 2020 Been doing some reading. Looks like it's just a regular power 9V 1A; I have heaps of those. So really it's only the oddball connector that's an issue. I could probably 3D design/print up a connector easy-as. Or even just some standard breadboard wires. Is there any reason people aren't/haven't done this? Quote Link to comment Share on other sites More sharing options...
+Andrew Davie Posted October 11, 2020 Author Share Posted October 11, 2020 1 hour ago, mksmith said: If I come across one in the next few weeks I'll get back to you ? In the meanwhile I'll try making a converter. Could you please correctly label the pins on the image -- this is looking at the end of the plug that plugs into the '7800. Also, I'd like some measurements - do you have a micrometer? pin center to center would be enough to get me started. Any/all measurements you care to give would help me. Plan is, I'd make a simple converter - plug the converter into a 7800, and then plug a standard 9v1A barrel plug into the converter. It's a wonder nobody seems to have done this already....? I could make one, send to you to see how it works....?? Quote Link to comment Share on other sites More sharing options...
+mksmith Posted October 11, 2020 Share Posted October 11, 2020 Happy to help out in any way Andrew ? The pinout is shown - the one I have is a standard 240v. Unfortunately no measuring thingy except a ruler (but see below)... Console5 sell adapters which I should probably order and build a couple with (but going to take a while to deliver!!) https://console5.com/store/atari-7800-pigtail-dc-cable-and-plug-for-custom-power-supply-5-foot-1-5m.html People have installed barrel connectors but I haven't really found a well documented way of doing that but would be happy to make that mod. Maybe @-^CrossBow^- or @juansolo might be able to help out here?? Guys?? Quote Link to comment Share on other sites More sharing options...
+-^CrossBow^- Posted October 12, 2020 Share Posted October 12, 2020 Yes a few weeks ago I was selling adapters just like this that have the 7800 power port on one end and a 2.5mm x 5.5mm barrel jack on the other end wired so you could power the 7800 with a master system, Megadrive, Jaguar, etc compatible power supplies. I sold one to @CyranoJ but as shipping was going to be crazy, I actually shipped it to a US address for him and he got it from there. 2 Quote Link to comment Share on other sites More sharing options...
+mksmith Posted October 12, 2020 Share Posted October 12, 2020 Ah ok thanks @-^CrossBow^- for the update ? Quote Link to comment Share on other sites More sharing options...
+mksmith Posted October 12, 2020 Share Posted October 12, 2020 Looks like Dave Curran @ tfw8b might have done the barrel jack mod on a Pal machine (most info is NTSC): Atari 7800 PAL Composite mod (thefuturewas8bit.com) I'll do some voltage measuring tonight... Quote Link to comment Share on other sites More sharing options...
+Andrew Davie Posted October 12, 2020 Author Share Posted October 12, 2020 2 minutes ago, mksmith said: Looks like Dave Curran @ tfw8b might have done the barrel jack mod on a Pal machine (most info is NTSC): Atari 7800 PAL Composite mod (thefuturewas8bit.com) I'll do some voltage measuring tonight... Please don't hack/modify the machine. I'm a bit of a purist on these things and would hate to see it damaged this way. Especially when a converter is easy to do and lets you keep the original as-is. Quote Link to comment Share on other sites More sharing options...
+mksmith Posted October 12, 2020 Share Posted October 12, 2020 9 minutes ago, Andrew Davie said: Please don't hack/modify the machine. I'm a bit of a purist on these things and would hate to see it damaged this way. Especially when a converter is easy to do and lets you keep the original as-is. I get you there mate ? What about soldering in a compatible jack (such as this) as I should be able to attach it to the points in Dave blog (will verify of course). 2 Pin LED Strip Connector to 2.1mm DC Socket | Jaycar Electronics Quote Link to comment Share on other sites More sharing options...
+Andrew Davie Posted October 12, 2020 Author Share Posted October 12, 2020 2 minutes ago, mksmith said: I get you there mate ? What about soldering in a jack such as this as I should be able to attach it to the points in Dave blog (will verify of course). 2 Pin LED Strip Connector to 2.1mm DC Socket | Jaycar Electronics Looks like a male end, and we need a female end to connect power to the 7800. And the pin spacing - that's crucial. Honestly, I think I can make one, given the correct measurements, that will be spot on. Quote Link to comment Share on other sites More sharing options...
+mksmith Posted October 12, 2020 Share Posted October 12, 2020 I just went down an picked up some stuff from Jaycar - will look at it tonight. Will be done in a non-intrusive way ? Quote Link to comment Share on other sites More sharing options...
+Andrew Davie Posted October 12, 2020 Author Share Posted October 12, 2020 Just now, mksmith said: I just went down an picked up some stuff from Jaycar - will look at it tonight. Will be done in a non-intrusive way ? Ha, OK 1 Quote Link to comment Share on other sites More sharing options...
+batari Posted October 12, 2020 Share Posted October 12, 2020 Does it boot to Asteroids and not the cart? If so, I can help. 1 Quote Link to comment Share on other sites More sharing options...
juansolo Posted October 12, 2020 Share Posted October 12, 2020 9 hours ago, mksmith said: People have installed barrel connectors but I haven't really found a well documented way of doing that but would be happy to make that mod. Maybe @-^CrossBow^- or @juansolo might be able to help out here?? Guys?? The easiest most secure way we've done it is to get a 2.1mm DC jack (https://www.rapidonline.com/truconnect-2-1mm-single-hole-chassis-skt-20-0980) ream out the hole slightly and bolt that in. It's annoying if you have to do work on the 7800 as you have to unsolder it everytime, but it's no big deal. I've also seen it done by glueing a jack like this (https://www.rapidonline.com/switchcraft-rapc722x-dc-power-socket-pcb-mount-2-1mm-20-0960) upside down where the original one was, then securing it with a cabletie through the board also. It's not going to be as solid, but it at least will come out with the board. 6 hours ago, Andrew Davie said: Please don't hack/modify the machine. I'm a bit of a purist on these things and would hate to see it damaged this way. Especially when a converter is easy to do and lets you keep the original as-is. The PAL machine is barely tolerable as Jack delivered it so likely you'll have already crossed that bridge. May as well go all in. Quote Link to comment Share on other sites More sharing options...
rj1307 Posted October 12, 2020 Share Posted October 12, 2020 In the attachment the .stl file with the plug for the power supply may be useful. Pins for this: https://www.tme.eu/pl/details/hdp20-1662911/wtyki-i-gniazda-d-sub/te-connectivity/166291-1/ Printout on a 0.2mm nozzle, PLA material. A7800.stl Quote Link to comment Share on other sites More sharing options...
+Andrew Davie Posted October 12, 2020 Author Share Posted October 12, 2020 3 hours ago, batari said: Does it boot to Asteroids and not the cart? If so, I can help. TY. What's happening is we have a report of PlusCart working on NTSC 7800 but the same cart NOT working on PAL 7800. Symptoms are that the menu code works fine for the first page, but when going to the next page, an unexpected game starts playing. It appears to be the 47th game in the directory. What I'm trying to understand is what's different about the PAL/NTSC 7800 where the same hardwire/firmware would work on one, but not the other. In particular, it seems from the flow of things that the joystick must be being detected when not expected, along with an unexpected selection item. Really hard to diagnose without a machine, hence I'm seeking a machine to borrow. Quote Link to comment Share on other sites More sharing options...
+Andrew Davie Posted October 12, 2020 Author Share Posted October 12, 2020 39 minutes ago, rj1307 said: In the attachment the .stl file with the plug for the power supply may be useful. Pins for this: https://www.tme.eu/pl/details/hdp20-1662911/wtyki-i-gniazda-d-sub/te-connectivity/166291-1/ Printout on a 0.2mm nozzle, PLA material. A7800.stl 138.17 kB · 1 download Very useful, TY. Quote Link to comment Share on other sites More sharing options...
+mksmith Posted October 12, 2020 Share Posted October 12, 2020 3 hours ago, batari said: Does it boot to Asteroids and not the cart? If so, I can help. Yes! 2 hours ago, juansolo said: The easiest most secure way we've done it is to get a 2.1mm DC jack (https://www.rapidonline.com/truconnect-2-1mm-single-hole-chassis-skt-20-0980) ream out the hole slightly and bolt that in. It's annoying if you have to do work on the 7800 as you have to unsolder it everytime, but it's no big deal. I've also seen it done by glueing a jack like this (https://www.rapidonline.com/switchcraft-rapc722x-dc-power-socket-pcb-mount-2-1mm-20-0960) upside down where the original one was, then securing it with a cabletie through the board also. It's not going to be as solid, but it at least will come out with the board. The PAL machine is barely tolerable as Jack delivered it so likely you'll have already crossed that bridge. May as well go all in. 31 minutes ago, rj1307 said: In the attachment the .stl file with the plug for the power supply may be useful. Pins for this: https://www.tme.eu/pl/details/hdp20-1662911/wtyki-i-gniazda-d-sub/te-connectivity/166291-1/ Printout on a 0.2mm nozzle, PLA material. A7800.stl 138.17 kB · 1 download Thanks guys for your assistance! Well the bad news is I just blew the 2200uf cap ? (pop scared the shit out of me!!) I checked everything - my supply matched 9v DC 240V 1A centre negative, measured the voltage pins to ensure they were correct before I attached my cable, then checked for shorts etc. Now I never actually powered the machine but I'd assume it could be done for. Apologies Andrew - will have have to replace the cap and give it a test. Feel like a bit of dumb-ass but a learning experience none the less ? Quote Link to comment Share on other sites More sharing options...
juansolo Posted October 12, 2020 Share Posted October 12, 2020 1 minute ago, Andrew Davie said: TY. What's happening is we have a report of PlusCart working on NTSC 7800 but the same cart NOT working on PAL 7800. Symptoms are that the menu code works fine for the first page, but when going to the next page, an unexpected game starts playing. It appears to be the 47th game in the directory. What I'm trying to understand is what's different about the PAL/NTSC 7800 where the same hardwire/firmware would work on one, but not the other. In particular, it seems from the flow of things that the joystick must be being detected when not expected, along with an unexpected selection item. Really hard to diagnose without a machine, hence I'm seeking a machine to borrow. Mine is doing exactly the same but @marauder666 is already mentioned it to you, so I didn't see much point in me chiming in other than to say 'me too'. 1 Quote Link to comment Share on other sites More sharing options...
juansolo Posted October 12, 2020 Share Posted October 12, 2020 1 minute ago, mksmith said: Yes! Thanks guys for your assistance! Well the bad news is I just blew the 2200uf cap ? (pop scared the shit out of me!!) I checked everything - my supply matched 9v DC 240V 1A centre negative, measured the voltage pins to ensure they were correct before I attached my cable, then checked for shorts etc. Now I never actually powered the machine but I'd assume it could be done for. Apologies Andrew - will have have to replace the cap and give it a test. Feel like a bit of dumb-ass but a learning experience none the less ? If you've blown the cap you got the polarity backwards of the PSU. 1 Quote Link to comment Share on other sites More sharing options...
+Andrew Davie Posted October 12, 2020 Author Share Posted October 12, 2020 2 minutes ago, juansolo said: If you've blown the cap you got the polarity backwards of the PSU. Center-negative is not that common in my experience. It was a bit of a surprise to read that. But in any case, you should be measuring the polarity on the good PS and making sure you have the same on the one you're making. Also, I was planning to whack in a diode on my effort so it would be absolutely save to plug the thing in the wrong way or use an opposite-polarity PS. Oh well... such is life. 1 Quote Link to comment Share on other sites More sharing options...
marauder666 Posted October 12, 2020 Share Posted October 12, 2020 (edited) Maybe Q10, Q11 and the regulator are dead too, try cap first though. Centre negative, very common for guitar pedals. Edited October 12, 2020 by marauder666 1 Quote Link to comment Share on other sites More sharing options...
Like us on Facebook
Follow us on Twitter
AtariAge on Instagram
Watch us on YouTube
Chat on Discord
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.