5200 4 port games won't start

[Jdgreen]

I finally got it to power up. My original power supply was putting out proper voltage when tested with meter with no load but would drop to nothing when connected to 5200 load. It's the power supply that is glued together, so I just used a different one for now. Now the game screen comes up and it won't start. I tried 3 different game and none start. I tested the controller and wires to connector and when I press start it connects (when looking at connector on controller cable end) left to right top row pin 5 to top row pin 2. With controller  unplugged I jumped these two pins in reverse of course and still game won't start. Does the controller connector need to be plugged in to start the game? Do the start pins need to see a certain voltage or resistance or do they just need to connect together? Thanks.

[SoundGammon]

Are you plugged into the far left port?

[Jdgreen]

Yes.

[SoundGammon]

Just looked at the diagram of the controller, looks like pins 4 & 7 connect the start button.

[Jdgreen]

Weekend tests were reset, and deoxit all removable IC. Tested voltage at both heat sink vrs is 5.1 volts. Read up on pokey, is this a possibility? I plug in Popeye game and theme song plays at beginning, so could pokey be just bad on controller signals and still play game sounds? Qbert and frogger don't make any noise when turning on console. Is there a way to make sure signal is getting to pokey to start game? My pokey has a component soldered across a couple pins, that I haven't seen on other photos of circuit boards. I would post photos, but I don't now how yet. Thanks.

[Jdgreen]

Here is my circuit board, and frogger screen photo. If it works.

[+-^CrossBow^-]

A few things to mention here.

 

First some of the repair work you have on your mainboard is factory done and is nothing to be concerned about and normal since you have the Rockwell SALLY installed that is known to have issues and it appears that Atari did the factory service work to correct for it.

 

If you have checked all the pins for proper continuity on the controller cable end of things, then at that point it could very likely be one or more of the 4052 MUX chips that handle the signals on the controller ports. While I supposed it could be possible that the POKEY has some issue, I would look to the 4052s first. Check the service manual flow chart to get an idea on which IC/ICs to check.

 

Another thing to keep in mind is that Atari like most back then, had a tendency to use single wipe sockets and now 40 years in, those are starting to get worn out and replacing sockets on some of these older systems is not uncommon either.

 

[Jdgreen]

Okay thanks. I will look for a service manual flow chart. 

[Jdgreen]

Okay found manual and flow chart and pin out of 4052 just wanted verification. I have .2 volts at pin 6. In photo it's the pin I am pointing to, is this pin 6 on 4052?  Are 4052 plug and play or do they need programming? Also noticed two resistors on right side of board below sheet metal shield get hot enough you can only stand to hold your finger on it for a couple seconds. Is this normal? I realized resistors get hot just not familiar with how hot these should be. Flow chart says to swap out u9 -1and u11-2  if I understand correctly the number designation 1 mean swap u9 and retest  then u11 if still 0 volts, or does it mean to replace both. Thanks Crossbow.

[Jdgreen]

I need to add the test was done with game cart installed and controller disconnected. Didn't see anything in flow chart about how this should be.

[Jdgreen]

Not sure what flow chart taught me, but after replacement of U9 game wouldn't start and still .2 volts on pin 6 of 4052 mux and pin 6 of U11. Replacement of U11 4052 mux did repair no start of game, but still have .2 volts on pin 6 of U9 and U11. With game cartridge removed both pin 6 have 5 volts. To conclude, I don't know what the voltage measurement would have been before I replaced U9 and U11 with game cartridge removed, and I don't know what flow chart required before tests. If I had to do it over I would do tests with no game cartridge installed. Thanks Crossbow!

[+-^CrossBow^-]

17 hours ago, Jdgreen said:

Not sure what flow chart taught me, but after replacement of U9 game wouldn't start and still .2 volts on pin 6 of 4052 mux and pin 6 of U11. Replacement of U11 4052 mux did repair no start of game, but still have .2 volts on pin 6 of U9 and U11. With game cartridge removed both pin 6 have 5 volts. To conclude, I don't know what the voltage measurement would have been before I replaced U9 and U11 with game cartridge removed, and I don't know what flow chart required before tests. If I had to do it over I would do tests with no game cartridge installed. Thanks Crossbow!

Glad you got it sorted. I believe I do those tests with Pete's test cart in the system. But I mainly was looking for activity on the pins when I was using my scope more than the actual voltage readings at the time. But yes, those 4052 MUX chips are very prone to ESD and while Atari was busy with all the different fixes for ESD on the 2600, they neglected this for the 5200 it would seem. I'm sure it was even more of an issue back in the day, when the console were likely sitting on carpet and people plugging in controllers while the system was on.