Need help computer stopped working

[Sean39]

Hi

I think I made a mistake by accident and it took the computer out.

 

I had the computer on but forgot to turn off the Peripheral expansion system

while pulling one memory card and placing another one in it.

 

I remember and turned off the computer, but when it turned back on I was left with a black screen and the computer making noises

over the monitor speaker. Now the computer is dead.

 

Did I take out the ram chips by accident in the computer since I was changing out the 32K ram card.

Need help getting the computer back up and going.

 

Thanks

 

[WhataKowinkydink]

Does the console work just by itself?

[+arcadeshopper]

Usually the console will survive that. If you unplug the flex cable does the console work?

Sent from my LM-G820 using Tapatalk

[Sean39]

no console is blank screen black and speaker making high pitch noise.

 

Could the computer just failed and I thought that placing the ram card in did it

while the unit was powered on did it. This is the 32K card in the expansion unit

 

it was working fine till I did that.

 

 

Edited April 24, 2020 by Sean39

[RickyDean]

9 hours ago, Sean39 said:

no console is blank screen black and speaker making high pitch noise.

 

Could the computer just failed and I thought that placing the ram card in did it

while the unit was powered on did it. This is the 32K card in the expansion unit

 

it was working fine till I did that.

 

 

Probably not, the card was powered, so when you pulled it, voltages shorted at the slots where you plug in the card, and if it is a standard PE box, the voltage can be 18 volts and that is a lot to short against the 5 volt lines of chips and circuits, or a dead short to ground lines. This can destroy buffer chips to include some of the chips in the flex card slot on the side of the TI. Yes you can damage more than the cards in the Box.  

Edited April 24, 2020 by RickyDean

[+dhe]

So you had the computer and pbox on while inserting and / or extracting a card.

Yea, it's bummer TI didn't make their cards hot plug compatible (a small joke) ?

 

So now, you unplug your console from the PEB. You turn on the console on and you

get:

   "blank screen black and speaker making high pitch noise."

 

That verifies the console took a hit for your TI time. The is a hardware debugging pin

here on atariago by John Guion. I'd start there. My best guess is the 9901 took a hit.

There is a particular point in the power up sequence where if interrupts don't get cleared

for any reason, you can end up with similar problems.

 

d.

[Sean39]

Ok I will do that.

Till then I just order a replacement computer. Since I figure this may take a while to trouble shoot and repair

 

 

How do I find this

The is a hardware debugging pin

here on atariago by John Guion

Thanks

 

Edited April 24, 2020 by Sean39

[Sean39]

Hi I just received the new computer that says it works.

Well it does work but there seems to be an issue.

 

When I turn it on the main screen flashes on only for a second then goes blue.

 

I found if I press the function and the +  it reloads and the main screen comes up.

 

It also seem to load all software and games ok, so why when I first turn the computer the main screen pops up

only for a second and goes blue.

Again if I reset the computer by pressing the Function and + together it reloads and the main screen comes

up.

 

What can I do to fix this problem.

 

Thanks

 

 

[+dhe]

At the top of the forum you will see 'pinned' resources.

 

Probably John Guion's is the easiest to follow, here is a link that will take you to it...

 

 

 

 

[Ed in SoDak]

7 hours ago, Sean39 said:

When I turn it on the main screen flashes on only for a second then goes blue.

I found if I press the function and the +  it reloads and the main screen comes up.

Are you using a flatscreen tv? I'm wondering if it's a sync problem and the TI might work fine on an old analog CRT TV. When modern TVs lose track of the signal, they often just show a blank blue screen.

[Sean39]

I am using a CRT. Would the graphics chip have dirty contacts on the chip. I think it is in a socket ?

 

Well the computer does not load up the main screen that say TEXAS instruments 1981.

Now it will load it up if I press the function key and + key at the same time that reboots the computer.

 

Thanks

 

Edited April 29, 2020 by Sean39

[+arcadeshopper]

I am using a CRT. Would the graphics chip have dirty contacts on the chip. I think it is in a socket ?
 
Well the computer does not load up the main screen that say TEXAS instruments 1981.
Now it will load it up if I press the function key and + key at the same time that reboots the computer.
 
Thanks
 

So it will warm boot but not cold boot.. I have a console in my stack that does this as well. No solution yet..

Sent from my LM-G820 using Tapatalk

[Sean39]

Yes that the way it is.

 

Thanks

 

[Sean39]

That computer has gone to rest no longer works. I have one that does work and will have to use it.

 

It just stop working. Really not sure what was wrong in it but it now does not function at all.

 

For now I will store it till I have time to try and repair it.

 

Thanks

 

[matthew180]

On 4/23/2020 at 4:20 PM, Sean39 said:

but when it turned back on I was left with a black screen and the computer making noises

over the monitor speaker.

This is known as a screaming banshee.  I thought this problem, and the common solution, were well characterized...  The sound chip "wakes up" (powers on) in a mode where it is generating sound, and one of the first things the computer does when it powers-on is to shut-off the sound chip.  So the tone you hear when you turn the computer on is not specifically created by the computer and programming.  The duration of the tone is the time it takes to get the sound chip silenced.

 

If the sound chip is making noise when you power on, that means the CPU has not even executed the first handful of instructions.  However, you know the VDP is working (or the sound chip would not be working), and the sound chip.  The troubleshooting guides should probably get you to an answer.  You will probably have to be able to desolder ICs though, and install sockets, etc.

[Sean39]

Ok I will look and see what other chips may have gone bad and see if I can get the computer back up and going

Thanks