Black screen screaming tone.

[Sinphaltimus]

Just received a donated console. Power brick, strange ac adaptor for the plug that doesn't seem to change anything. rf adaptor,TERMINAL EMULATOR CART oldies but goodies games 1 cassette documentation, speech synth and some books.

Plugged it in turned it on - black screen, 3 tone sound that pierces the ears. What should I be looking at in terms of repair?

I read someplace the TE cart is good for speech things. Otherwise useless without an rs232?

[00WReX]

Hello Sinphaltimus,

 

From my understanding, there are many things that can fail and cause this symptom.

 

One of my TI's had the same symptom and it turned out to be one of the SRAM chips had failed.

 

http://atariage.com/forums/topic/254749-greasy-cartridge-port/?do=findComment&comment=3558036

 

Good Luck with it.

 

Cheers,

Shane

 

 

[+Schmitzi]

Hi, do you maybe have a pic from the brick and the imprint (voltages), and console plug ?

[dphirschler]

I once had this symptom and I replaced the sound chip and fixed it.

 

Darryl

[Stuart]

The processor is not getting far enough through the 'boot code' to silence the sound chip and initialise the screen. As others have said above, there are any number of failure points that can cause this. One easy thing you might want to try is to remove and refit the set of three socketed GROM chips and the sound chip, just in case they're making bad connections in the sockets after all these years. Also try swapping the PSU board and power brick for known working ones, see if that makes a difference. If that doesn't help, then its out with the schematics and test equipment ...

[Sinphaltimus]

Turned in early last night. I'll start trouble shooting after breakfast.

 

Schmitz, I'll post a pic of the power brick soon but I didn't use it. I plugged it in to my known working power brick and video cable do at least I know it's the console itself.

 

Haven't cracked it open yet.

 

But I will....

 

However, my testing equipment is limited to a multi meter. I hope that's enough.

 

At the very least, I hope the keyboard works.

Edited October 30, 2016 by Sinphaltimus

[Sinphaltimus]

Hi, do you maybe have a pic from the brick and the imprint (voltages), and console plug ?

 

 

[+Ksarul]

Standard power supply. The Green plug was something TI supplied to all existing users to correct a potential grounding issue with one of the power supplies. It came in two forms--the plain plug you have (with a built-in fuse) or with a short extender cable with the fuse in a box in the middle.

[Sinphaltimus]

Well it looks like I have a project ahead of me.

First I've seen the rf shield for the cart adaptor and the mini heatsink for some other chip, and different power cord connection on the inside.

 

I haven't been at this very long so I'm bound to see lots of things for the first time.

 

Including the bottom of this mainboard.

 

Everywhere I looked I could see solder problems. I almost wanted to believe someone else was replacing all the chips themselves and gave up at some point.

 

 

Check out these pics and let me know what you think. I've never seen a solder point with a hole clear through the center as if the pin that was there simply evaporated. I'm afraid to think what this means as far as repair. And ther are a lot of spots like these. Not just one or two.

 

 

I think I have a lot of reheating and resoldering to do.

[+Ksarul]

Yes, there are two different plugs used inside. One has the plug going straight to the board (later powere supplies) and one has a short cable with the connector on the end. The power supplies will work with other mother board variants, but you have to build an adapter cable to connect them, as the connectors are different. The weird ones used in the early power supplies are readily available on eBay though (they are a type of 4-pin Molex connector).

[Sinphaltimus]

I think it's beyond me at the moment. I resoldered everything that appeared to need it and same symptom. So I think I'm going to shelf it for a while. I got a terminal emulator II cart, spare PSU, another speech sych (for modding power pass through), rf modulator and hopefully a working keyboard out of the donation. It would have been nice to have a working console but I'm not gonna sweat it.