Yet Another 5200 Hardware Problem

[Ze_ro]

So here's the story... a long time ago, I bought a 5200 off eBay. All I got was the system with no cords, controllers, or games. I figured I'd just put it together piecemeal. Eventually I got some games, and one of my friends ended up scoring a 5200 as well. I borrowed his controllers in order to test out my system, and I couldn't get any of the games to start. I knew beforehand that the controllers with horrible, so I just assumed his controllers sucked and went on with life knowing that at least the games started up, so the system must work.

 

Flash forward a couple of years and I finally get around to getting some controllers off eBay. They were old ones, but I'm a pretty handy guy, so I figured I could get something working. Besides, I want to eventually build a whole controller from scratch, and I needed to know certain things about the controller. I also bought the track ball, as I had heard that it's buttons were somewhat more reliable. But I still couldn't get any of the games to start... and what's more, a lot of times, the system wouldn't turn on, or would just shut itself off. Eventually, I came to the decision that the universal power supply that I was using just wasn't powerful enough to run the system (I think it maxes out at 300mA while the 5200 draws a whopping 1.95A... it's actually kind of amazing that the system would turn on at all). I figured maybe it wasn't enough juice to read the controllers properly.

 

About a month later, I finally tracked down the proper power supply for the damn thing... The problems with the system shutting off went away, but the controllers still don't work. Reset, and 4-9 on the keypad work fairly reliably, and on all my controllers... I was also able to get some reaction to a joystick button when Super Breakout was plugged in (the score turned red when I pressed it). But no matter what I tried, Start, 1-3, and *0# don't seem to work at all. I even tried short circuiting the pins on the controller port to simulate a Start button press, but nothing works.

 

I was looking at the schematics for the 5200 controller, and Start-1-2-3 share a common pin... I've come to the conclusion that there must be a problem inside the 5200... perhaps a burned out chip or a dead resistor or something. Has anyone else heard of this happening with a 5200? I've opened the thing before, and it was a nightmare. I didn't find anything obviously wrong either, so I went through the other nightmare of putting the thing back together (that shielding is worse than the controllers!)

 

This whole thing has been a really bad experience, but I still want to put together a working 5200... I think my best bet would be to just buy a new system and toss this junker... anyone have any other suggestions on what to try?

 

--Zero

[+remowilliams]

I even tried short circuiting the pins on the controller port to simulate a Start button press, but nothing works.

Maybe bad port MUXes or a bad Pokey?

 

I don't get why people complain so much about the shielding. It's just a bunch of little tabs to unfold.

[midnight magicman]

I'm not a tech guy @ all but I'll tell you my experience.

 

Got a used 5200 with power supply/rf, trackball & 52cx controller. The lady I bought it from warned me that everything worked except the standard controller.

 

She was right, I took the controller apart & cleaned the flex circuit & put foil tape on the bottom of all the buttons. Everything looked good but when I put the controller back together the "Pause", "Reset" & top left "Fire" button wouldn't work no matter what tweaking I did.

 

I called Best Electronics & the guy had me look @ the flex circuit & tell me the # on it. He said it was the Rev. 6 Flex & that they are unreliable, so I ordered a Rev 9 flex circuit from him along with a new auxilary pad (start pause reset). Added the new parts, threw the old ones away & it's worked perfect ever since. In other words, it may just be the flex circuit giving you problems. The power problem was probably just independent of that.

 

Peace

[mimo]

Get the flex circuits and re-build kits for the joysticks from Mr Retro Gamer he is a regular on these forums, and sells the same bits as best but without the $minimum.

 

If fixing the sticks does not solve the problem and you really want a 5200, then get a replacement NEW motherboard from Best, it;s the best $35 I spent on the 5200

Edited December 29, 2007 by mimo

[shadow460]

If it's a flex circuit, his Trak-Ball would work, and he'd have got a response from shorting the pins.

[mimo]

Oops, should have read all the post so get a new MB from Best, problem solved

[Prodos8]

Check continuity for pin 4 & 7 at the connector and the appropriate 4052 (I think these pins are divided between 2 chips). If the continuity is good replace the appropriate 4052's otherwise look for a bad/broken solder joint at the connector or a broken trace on the PCB. If you replace the 4052's and have good continutity for the pins and it still doesn't work then I'd try replacing the pokey chip.

 

Buying a new motherboard from Best's would certainly be the easiest, but the 4052s would probably run you less than $5 (Fry's sells them around here for $2.25 each -- which is a ripoff) to replace.

[BigO]

Yeah, what Prodos8 said.

 

I have the impression that we're talking about a 2 port machine. I don't have access to a schematic for the 2 port. (Can anyone point me to one?) Even without the exact schematic, the 4 port schematic and a little experience indicate a likely problem with a 4052. Given the proper schematic, we could probably narrow it down to the exact chip you need to test/replace.

 

In order to find the bad chip when I had a similar problem with my 2 port, I had to break out the oscilloscope and the chip specs then look at the waveforms on the input pins and see where the output didn't match the expected result. If your 4052's are socketed, buy enough chips to replace them all. If they're not socketed, buy sockets with them.

 

If they're not socketed, know that it's a pain to desolder chips. (It can be a little easier if you're sure you've got the bad chip identified and are absolutely sure you won't be reusing it.)

[+remowilliams]

On a two port 5200 - Port 1 COL3 (Pin4) goes to 4052 A9, All ROWS (Pins 5-8 ) to 4052 A11.

 

 

i.e.

Maybe bad port MUXes or a bad Pokey?

Edited December 31, 2007 by remowilliams

[BigO]

On a two port 5200 - Port 1 COL3 (Pin4) goes to 4052 A9, All ROWS (Pins 5-8 ) to 4052 A11.

 

 

i.e.

Maybe bad port MUXes or a bad Pokey?

 

(A smarter guy than me would have made note of those things while tracing it out to do a repair...)

 

So, there's where'd I'd start replacing chips or tracing signals: A9.

[Charlie_]

I had a 5200 system that had the same problem years ago. Replacing the POKEY chip fixed it.

In that case you might want to ebay a system or parts system for as little money as possible.

Just an idea.

[BigO]

Some kind soul reminded me of where to find the 2 port schematic, in a file that I already had thanks to the fine folks at AtariGuide.com: http://www.atariguide.com/help/care.htm

 

Scroll down to where it says "Field Service Manual". You can view the 2600 manual while you're in the neighborhood.

Edited January 4, 2008 by BigO

[Ze_ro]

Well, I've traced things out, and it seems like there is continuity between the joystick port and 4052/POKEY leads, and the 10 resistors along the way are all good... I guess the next step is to replace some of these chips. I guess I might as well buy a POKEY or 2 from Best, and pick up some replacement controller parts while I'm at it... as for the 4052, this is a standard part, correct? Is this something I could find at the local electronic parts store, or will I have to track them down on the internet?

 

--Zero

[edweird13]

I was having similar problems to what you are having. I could not get the top fire buttons to work at all. Replacing the 4052's fixed it. I added sockets for the chips so they could easily be replaced in the future.

[BigO]

Well, I've traced things out, and it seems like there is continuity between the joystick port and 4052/POKEY leads, and the 10 resistors along the way are all good... I guess the next step is to replace some of these chips. I guess I might as well buy a POKEY or 2 from Best, and pick up some replacement controller parts while I'm at it... as for the 4052, this is a standard part, correct? Is this something I could find at the local electronic parts store, or will I have to track them down on the internet?

 

--Zero

 

The 4052 is an off-the-shelf part. I doubt you'll find it at Radio S hack, but a more hardcore parts supplier should have it. A search on 4052 keyword turns one up at the URL you listed.