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Power Up Issue


Hank Rearden

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I recently did a composite upgrade and replaced all the caps. I seem to be having issues with starting up a game. Some of the time when I power it on I get a high pitched whine and a garbled or partial picture. I pulled the power switch off and cleaned up the contacts using some Brasso and then alcohol. I did not add any grease back. Is that my problem most likely. Should I get some sort of grease for the contacts? If so, what kind specifically?

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I clean them with alcohol and a brass brush - never used dialectic grease on these types of contacts, & I wouldn't. Atari switches are hot switched and arc. Dialectic grease is silicon based and will convert to silicone carbide which is abrasive if used in switches that arc.

Edited by mojoatomic
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Any thoughts on why I have an issue then?

With those symptoms, yeah a few come to mind.

 

Check your voltage on the VR, it needs to be very close to 5v - I would do this when the issue is presenting.

 

Make sure C201 is installed in the correct direction as it's the reset line. Clean the reset switch contacts.

 

Crush a q-tip with a pair of pliers to pancake it out, soak it in alcohol and give the female cart connector a good cleaning.

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With those symptoms, yeah a few come to mind.

 

Check your voltage on the VR, it needs to be very close to 5v - I would do this when the issue is presenting.

 

Make sure C201 is installed in the correct direction as it's the reset line. Clean the reset switch contacts.

 

Crush a q-tip with a pair of pliers to pancake it out, soak it in alcohol and give the female cart connector a good cleaning.

It's one of your brand new VRs but I'll check it just the same. C201 is installed correctly.

 

I didn't think of the reset switch. Maybe I'll pull them all off and clean them like I did the power switch. I'll also give another go at the cartridge slot.

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It's doubtful in this case, but new parts can be bad. Besides, it's so easy to check, so why not?

 

I clean all of the switches as a general rule - and it's saved me a lot of heartache. They REALLY get gummed up, especially if around pets or smoking, carpet, anything else you can think of over the past 40 years. They almost always look waxy and dull, but a good cleaning spruces them right up. The reset switch is real nasty one for sticking between settings if things are gummed up - watch that spring, I've shot more than my fair share across the shop.

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It's doubtful in this case, but new parts can be bad. Besides, it's so easy to check, so why not?

 

I clean all of the switches as a general rule - and it's saved me a lot of heartache. They REALLY get gummed up, especially if around pets or smoking, carpet, anything else you can think of over the past 40 years. They almost always look waxy and dull, but a good cleaning spruces them right up. The reset switch is real nasty one for sticking between settings if things are gummed up - watch that spring, I've shot more than my fair share across the shop.

Probably pull the other 3 off this weekend and see if that helps. So no grease required once they are cleaned up real good?

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No grease required :-)

I cleaned all the contacts with Brasso and soaked them in alcohol. All the copper contacts are nice and shiny and clean from any and all gunk. Now, anyone have any tips on getting them back on there again?! :? Basically I got them off by loosening one side and pried them off without too much trouble. So now one side is still curved and I was thinking of straightening the other side and rolling the contact back on. Probably need to hold it upside down in order to do so.

 

Anyone else have a method they've used that might help?

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I hold them upside down myself -

 

Basically, completely straighten out one side, leave other side curved. Put the switch together upside down, and the while it's upside down hook it on the base, turn right side up and using needle nose pliers, crimp closed. It takes a few to get it right, but then it's not really a big deal.

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I hold them upside down myself -

 

Basically, completely straighten out one side, leave other side curved. Put the switch together upside down, and the while it's upside down hook it on the base, turn right side up and using needle nose pliers, crimp closed. It takes a few to get it right, but then it's not really a big deal.

The good news is that I was able to reinstall the switches with the springs in them! So I can say with absolute certainty that dirty or gunky switches is most definitely not the problem with powering up.

 

It still only powers on correctly about 1/3 of the time give or take. When it does power on correctly it seems to run fine although I have left it running for more than it takes to play a game of Ms Pacman.

 

I tested the new voltage regulator. I get readings of 4.9-4.92 on the bottom prong and anywhere from 10.37 to 10.54 on the top prong and it doesn't seem to matter if it kicks on properly or not.

 

What else can I try?

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I assume it worked fine before hand?

 

Checked all your soldering?

 

did you remove the resistor that blends the audio and video signals into one for the RF

Which one is that?

 

Would the one that I added to pins 6 and 9 make a difference? Is that only for RF units and not for composite?

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Still trying to nail this power up issue down. I welcome any additional feedback to troubleshoot this.

 

And I have yet to hear from anyone on the Pitfall sound issue. I have 2 different Pitfall carts now, and the only sound I get on the CRT is running into logs. Swinging, falling, dying....no sounds. But if I hook up to an LCD TV, I hear everything.

 

I assume it worked fine before hand?

 

Checked all your soldering?

 

did you remove the resistor that blends the audio and video signals into one for the RF

I have not yet completely ruled out a possible soldering issue but since it seems to mostly only happen on Activision carts, I'm thinking soldering isn't the problem.

 

However, what resistor specifically are you referring to? When I did the composite mod, I completely removed the RF unit, the transistor 202, and resistor R209. I also removed the tall pink (I forget what it's called) but it's used for RF.

 

I also added a resistor underneath the board to pins 6 and 9. Is that done for either RF or composite?


 

Do you have any Activision carts? If you do, see what it does.

I do as of today. I purchased a second Pitfall and also Freeway. They seem to have by far those most problems. I put them in and they'll start right up on occasion. So I switched on and off in rapid succession and they'd be fine for some but then go on a run of like 12 times glitching and then it'd work again. I tested Donkey Kong (Coleco), Survival Run (Parker Bros. I think), Frogs & Flies (Mattel), Cosmic Ark (Imagic), as well as Space Invaders and Superman. All of the rest except Superman I would say had no issues. Superman had a couple but excluding the Activision titles I'd say 95% of the time the other titles came on as expected.

 

What do you think is the issue with Activision since you mentioned it specifically?

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I mentioned Activision specifically not because I think these is an issue with Activision, but because I think there is an issue with your cart connector - Activision boards are thinner than Atari and will exacerbate and expose issues with cart connectors more readily than Atari carts.

 

If the female cart connector is dirty or sprung, it's almost impossible to play an Activision cart and Atari carts will play, sometimes, with difficulty.

 

Put an Atari cart in the unit, turn it on an press forward (towards the top of the unit) on the cart and see if it has an effect.

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is it a 4 or six switcher

It is a 4 switch unit. Rev 13 board. RF removed. Composite mod installed. Resistor underneath attached to pins 6 and 9.

 

I mentioned Activision specifically not because I think these is an issue with Activision, but because I think there is an issue with your cart connector - Activision boards are thinner than Atari and will exacerbate and expose issues with cart connectors more readily than Atari carts.

 

If the female cart connector is dirty or sprung, it's almost impossible to play an Activision cart and Atari carts will play, sometimes, with difficulty.

 

Put an Atari cart in the unit, turn it on an press forward (towards the top of the unit) on the cart and see if it has an effect.

I did as you said and have little to no issue with any non-Activision carts. I pushed forward and backward with Asteroids in there and only when I pulled it half way out did it finally fault.

 

Freeway took several times to get going but once it boots it plays just fine. I cleaned the heck out of the slot and the cartridge.

 

I like your theory about the thin boards but they seem to play fine once booted. And once booted I can push and pull and it won't glitch.

 

Any other thoughts?

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I think you have a crystal oscillator that is not always starting up. I would replace the crystal.

 

It is 3.599575 MHZ and can be purchased for digikey , mouser etc.

What part is this on the board? I'm still a novice. :-D

 

Could this be tested by swapping chips with another unit?

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I do not own a four switch or any 2600 at the moment. The oscillator can be check with a frequency counter or scope but they are both expensive pieces of equipment.

 

I would just replace the part. It is not that expensive.

 

Look for a small metal part with part of the frequency stamped on it. Once you think you've found it take a picture and i can verify you have the right part. you might see XTAL or X101 or X??? on the circuit board.

 

Any help from a 4 switcher in locating the crystal? photo?

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