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Pole Position odd behaviour


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#1 scelbi8h OFFLINE  

scelbi8h

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Posted Sun Mar 11, 2018 4:08 AM

I'm going crazy with a Pole Position cartridge I got many years ago. About a month ago, it stopped working with the light sixer I have for general use - I get garbage after few seconds, and game freezes. 

 

What is strange here is that the same cartridge works as it should with all my other Atari consoles (several Jrs, another light sixer and two 7800s). It's just faulty with this specific console. 

 

I checked the console. Contacts are clean and all the other games work ok. Not the slightest issue. Even Pole Position from the Harmony cartridge runs ok.

 

What's going on here? 



#2 Keatah ONLINE  

Keatah

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Posted Sun Mar 11, 2018 6:20 AM

Wonder if the rom chip is degrading?

#3 x=usr(1536) OFFLINE  

x=usr(1536)

    Dragonstomper

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Posted Sun Mar 11, 2018 2:29 PM

Wonder if the rom chip is degrading?

 

Or if voltages are fluctuating on the light sixer but not the others.


Edited by x=usr(1536), Sun Mar 11, 2018 3:00 PM.


#4 scelbi8h OFFLINE  

scelbi8h

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Posted Mon Mar 12, 2018 10:13 AM

Wonder if the rom chip is degrading?

 

 

Or if voltages are fluctuating on the light sixer but not the others.

 

Thanks to both for your answers :)

 

Both theories are ok, but as I said, the problem occurs with this specific cartridge plugged in that console. If the ROM chip was degrading, wouldn't it be faulty with the other consoles? And if the voltage is fluctuating on the light sixer, why all other games work ok? This is the only cartridge of my +90 that freezes and show garbage.

 

It's a real mistery to me, I don't know how to face this issue.



#5 Keatah ONLINE  

Keatah

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Posted Mon Mar 12, 2018 1:07 PM

It's a possible theory. Could say it depends on how bad the cart is, and how out of spec the console is. If they're a little out of spec, each, it could add up to being way out of spec when both are combined.

 

---

 

When you have a new car and something fails, it usually stands out in contrast to everything else working perfectly. And it's an easy diagnosis + fix for the mechanic.

 

But in an old car, if something starts going out of spec, it tends to get lost in the noise of other failures and wear and tear. Is the bad mileage coming from a dirty air filter? Dirty oil? Bad bearings, dirty injectors. Fixing any one of the problems may or may not be "enough" to push it back in to spec.

 

---

 

Could this symptom be a "poster child" for how we will observe gradual failure on 40+ year old consoles and cartridges?

 

In an old console, it might be bad capacitors, worn end-of-life voltage regulator, weak spring-action on the cartridge connector, marginal power-brick output, Sloppy TTL rise/fall times. It's all additive. Fixing any one of the several wear'n'tear items/problems may be "enough" to push it back in to spec.

 

---

 

 

I checked the console. Contacts are clean and all the other games work ok. Not the slightest issue. Even Pole Position from the Harmony cartridge runs ok.

 

Contacts are clean, are they applying enough pressure to handle any variances in thickness of the PolePosition cartridge's PCB? Just a thought, I know of no issues applying to PP.

 

Also, understand Harmony is rather new in comparison to a much older PP cart. The H cart is providing crisp and in-spec rise/fall times on the signals, likely enough to overcome any slop in the older console. IF that's the real problem.

 

---
 

Don't know what else to say other than pull out the oscilloscope and logic analyzer to dig in further, or try another PP cart!



#6 x=usr(1536) OFFLINE  

x=usr(1536)

    Dragonstomper

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Posted Mon Mar 12, 2018 5:46 PM

It's a possible theory. Could say it depends on how bad the cart is, and how out of spec the console is. If they're a little out of spec, each, it could add up to being way out of spec when both are combined.

 

This.  I don't how many times I've run into a situation that falls into the category of 'but it works over there', only to later find that there was a secondary issue going on that was causing or exacerbating the primary issue.

 

Here's an easy test: swap the light sixers' power supplies between them and see if the problem follows from one machine to the other. If it does, you've got a possible PSU problem; if it doesn't, move on up the chain until you find it.  Good luck!






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