800XL has very warm antic chip

[hueyjones70]

I have been working on an 800XL that would boot up then go to a blank screen after about 1 minute, sometimes sooner. I noticed that the antic chip got very warm so I swapped it out with another and got the same results. How warm should the antic chip get, this one gets warm enough that it is uncomfortable to touch. Are there any former techs out there that know anything about troubleshooting motherboards. I know that the normal procedure is to just get another one but there must be someone who used to actually fix things instead of just replacing them.

[+tf_hh]

Diagnostics over 6000 miles distance is not the best idea, but I didn´t want your thread not narrated... the ANTIC could get a little bit warmer than other chips, except the CPU. After 10 minutes of operation the CPU ist in 99 of 100 cases the hottest one. Some CPU will be so warm, that you instinctive remove your finger from it. But ANTIC normally should not get so hot... some versions, dependent on the manufacturer, get warmer then others, but I would say, try the RAMs and CPU first.

[BillC]

Have you checked the voltage after the system goes to black screen?

 

I don't know the circuitry of the power supply you have, but some go into thermal protection mode and reduce power output when they overheat.

[+DrVenkman]

"Very warm" isn't terribly precise. I would say, however, that you ought to consider GTIA as a culprit as well, and really any other of the main ICs if by "black screen" you mean the system locks up.

[hueyjones70]

I was mistaken, it was the CPU. By black screen I meant that the screen goes dark, as if the computer was turned off and it will sometimes flicker but does not come back on.

[mellis]

I have been working on an 800XL that would boot up then go to a blank screen after about 1 minute, sometimes sooner. I noticed that the antic chip got very warm so I swapped it out with another and got the same results. How warm should the antic chip get, this one gets warm enough that it is uncomfortable to touch. Are there any former techs out there that know anything about troubleshooting motherboards. I know that the normal procedure is to just get another one but there must be someone who used to actually fix things instead of just replacing them.

 

 

With very little go on here, it sounds like you have a failing power supply that is cooking your Atari(s) when it warms up. If I were you, I would ensure that you are using one of the known-good types of power supply before continuing.

[hueyjones70]

I found the problem, there was a hairline break in the traces very near the CPU and evidently the heat must have caused abreak in the electrical circuit. Repair was made using a pen with conductive paint. Turned the unit on and it was still working after 45 minutes.

[ClausB]

Congrats. Repair it with solder when you can.