+Cafeman Posted December 1, 2002 Share Posted December 1, 2002 I fried both my 4-port and my 2-port on bad PCB's. (don't ask) I'm not ready to give up on my lil buddies though. I assume that a certain part of the 5200 board is what fried and that if I replace this part, I'll get my 5200 back. The question is -- how do I go about testing the board? I have a mulitmeter. Don't really know how to use it, there are so so many settings. If you have any suggestions, or if you know of somebody who knows how to do this, please speak up! You may just save a life (of a 5200) and my sanity! Quote Link to comment Share on other sites More sharing options...
+Mitch Posted December 1, 2002 Share Posted December 1, 2002 Did those suggestions I emailed you about your 4 port, a while ago, help any? I imagine it's the same part blowing on both systems. Do any of the components look fried? Mitch http://atari7800.atari.org Quote Link to comment Share on other sites More sharing options...
+Cafeman Posted December 2, 2002 Author Share Posted December 2, 2002 I took off the 4-port's case and the metal shield thing. Not sure how to tell if anything looks fried. Okay, you told me to check these components: U7 Pokey U2 6502 U3 Antic U5 GTIA *** note that I have not seen "U" anything on this 4-port board. However, I do see A7, A2, A3, and A5 which are big/long chips so I assume these are what you refer to. anyway, I see no burn marks or evidence of problems anywhere. Y1 crystal, left of power switch Q1 and Q2 transistors -- found 'em, don't see anything wrong to my newbie eyes. VR1 heat sink regulator -- found it-- no obvious problem. I don't know what to look for but other than some kind of orangish gunky stuff in various places around the board (looks like aged plastic / rusty kind of look) in tiny little splatters & such, I don't see anything on either side that I'd call a burned out look . Any more ideas? And can you confirm that U7 = A7, etc on my board as I mention above? Quote Link to comment Share on other sites More sharing options...
CPUWIZ Posted December 2, 2002 Share Posted December 2, 2002 What exactly were the symptoms, blank screen, no sound ... etc ? Quote Link to comment Share on other sites More sharing options...
cschell Posted December 2, 2002 Share Posted December 2, 2002 It would help to know how the PCBs were bad. Was power shorted to ground? Two address lines together? Two data lines? Chips in backwards? etc. That information would make it much easier to look for a particular failing in the 5200. Chad Quote Link to comment Share on other sites More sharing options...
+Mitch Posted December 2, 2002 Share Posted December 2, 2002 Ron, yes U7 = A7. Atari changed the designation on some of their boards for some reason. Chad, apparently the new 5200 cart boards had a manufacturing flaw on a few of them where there would be a trace connecting all of the cart pins. So basically, yes, power was shorted to ground. Mitch http://atari7800.atari.org Quote Link to comment Share on other sites More sharing options...
+Cafeman Posted December 2, 2002 Author Share Posted December 2, 2002 Yes, what Mitch said. say I did want to replace a few components. How do you go about getting the soldered chips out of the board? Do you cut them out somehow? Quote Link to comment Share on other sites More sharing options...
cschell Posted December 2, 2002 Share Posted December 2, 2002 Well a quick place to start would be to check if you still have power, and haven't blown the regulator or a fuse (although I doubt Atari used any fuses.) Use your DMM on voltage setting and see if you have 5 volts on a power pin relative to ground. That means black probe on ground, it's the foil everywher, and red pin on a power supply pin, like the last pin on a 74xx device. Chad Quote Link to comment Share on other sites More sharing options...
+Cafeman Posted December 2, 2002 Author Share Posted December 2, 2002 Okay, I'll try that tomorrow. Another question though: Can putting in a chip backwards really fry your system? I did indeed solder a 7408 logic chip on backwards and ... the cart just didn't work. It doesn't harm my 5200. Additionally, on one PCB there was a glob of stuff (solder or trace) which connected three lines which were narrow, long and close to each other. The cart simply didn't work. When I saw the problem, I took a utility knife and carefully scratch a vertical strip between the three lines -- and I got the cart working. On another PCB, a line was broken / cut. Again, the cart simply didn't work. No damage to the system. Obviously the logic flow just doesn't work when it isn't 100% up to spec. However, Chad you seemed to ask about these types of 'flaws' on the PCB as though you thought they could short the system. Thoughts? Quote Link to comment Share on other sites More sharing options...
cschell Posted December 2, 2002 Share Posted December 2, 2002 say I did want to replace a few components. How do you go about getting the soldered chips out of the board? Do you cut them out somehow? You unsolder them. Basically you heat up the solder on the pins with your soldering iron, and then remove it somehow when it's hot. Suction devices or solder wick are two commonly used methods. The suction devices are just plunger or bulb devices that create suction when you release them, and thus suck the solder into the device and away from the pin. Solder wick is a braided copper, you heat it along with the joint and the solder wicks up into the copper braid. It's very annoying on large devices, because you have to get all the solder of all the pins to remove the device. And plated through hole devices are sometimes hard to get completely clean. Some people have these things called skills that let them do this without much effort. Sadly, I'm not one of them. Quote Link to comment Share on other sites More sharing options...
+Mitch Posted December 2, 2002 Share Posted December 2, 2002 I believe the system powers up to a blank dark colored screen. Mitch http://atari7800.atari.org Quote Link to comment Share on other sites More sharing options...
cschell Posted December 2, 2002 Share Posted December 2, 2002 I believe the system powers up to a blank dark colored screen. So much for that idea. Quote Link to comment Share on other sites More sharing options...
CPUWIZ Posted December 2, 2002 Share Posted December 2, 2002 say I did want to replace a few components. How do you go about getting the soldered chips out of the board? Do you cut them out somehow? You unsolder them. Basically you heat up the solder on the pins with your soldering iron, and then remove it somehow when it's hot. Suction devices or solder wick are two commonly used methods. The suction devices are just plunger or bulb devices that create suction when you release them, and thus suck the solder into the device and away from the pin. Solder wick is a braided copper, you heat it along with the joint and the solder wicks up into the copper braid. It's very annoying on large devices, because you have to get all the solder of all the pins to remove the device. And plated through hole devices are sometimes hard to get completely clean. Some people have these things called skills that let them do this without much effort. Sadly, I'm not one of them. That is very interesting, I haven't seen a 5200 where the chips were not in sockets, I actually have what Chad calls "skill" and if you like you can send me your board and I'll socket all of the chips for you. You just have to pay for the postage. I would do it simply to see a 5200 without sockets. Quote Link to comment Share on other sites More sharing options...
+Cafeman Posted December 2, 2002 Author Share Posted December 2, 2002 I looked last night and I do believe the big chips are resting on sockets. So I can just pull them out? However, the transistors and capacitors and other thingies are soldered hard to the board. Quote Link to comment Share on other sites More sharing options...
CPUWIZ Posted December 2, 2002 Share Posted December 2, 2002 If you don't have an EPROM remover, you can use a small screwdriver and slowly lift one side of the chip, then the other ... repeat until you can remove it with your hand. Capacitors, resistors and transistors are always soldered into the board. Quote Link to comment Share on other sites More sharing options...
+Cafeman Posted December 2, 2002 Author Share Posted December 2, 2002 I do have an Eprom remover -- they are invaluable when, say, burning, testing, and making about, oh, 100 carts in your garage. 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.