Atari 800 xl acting strange.

[Mr Oni]

it works fine if you put a cartridge in it. But in basic the keys function wrong and when you try to run a program it says Run error or something like that. Control and clear does not clear the screen for example. I tried to see if it would work with a basic cartridge from my 400 but it does the same thing. Any ideas?

[+Nezgar]

Have you tried Keyboard & RAM tests in the self test?

(Hold Option on powerup with no SIO drives attached, or BYE in basic)

[Mr Oni]

Thanks i have very little experience with Atari computers ill check that now

[Mr Oni]

Ok so it did the test and one of the ram chips i take it is bad as it is white? and also the keyboard test the shift and control keys dont work. Do you think the ram chip could affect the keyboard?

[JR>]

Ok so it did the test and one of the ram chips i take it is bad as it is white? and also the keyboard test the shift and control keys dont work. Do you think the ram chip could affect the keyboard?

Shift and control only light up in the test if you press them along with another key, so they're probably fine. Bad RAM is a common problem. Time to open her up. If you're lucky some or all the chips will be socketed. If they are, try reseating all the socketed chips.

Edited April 28, 2018 by JR>

[Vyper68]

Ok so it did the test and one of the ram chips i take it is bad as it is white? and also the keyboard test the shift and control keys dont work. Do you think the ram chip could affect the keyboard?

 

As far as i know the RAM test would show RED for bad RAM the White one is the one the Atari is checking at any given time and also Control and Shift only show as working when pressed in combination with another key i.e. Control + A, Shift + A

 

Also Control + 1 and Break do not work in the Self-Test program so don't worry about those.

Edited April 28, 2018 by Vyper68

[JR>]

I wasn't paying attention....Vyper68 is correct, the white block is the one being tested (it loops) red would be bad ROM or RAM. Re-seating chips would still be a good next step if they are socketted. Did you boot the computer with the OPTION key held down? The RAM under the BASIC ROM doesn't get tested if you don't.

Edited April 28, 2018 by JR>

[Mr Oni]

 

I wasn't paying attention....Vyper68 is correct, the white block is the one being tested (it loops) red would be bad ROM or RAM. Re-seating chips would still be a good next step if they are socketted. Did you boot the computer with the OPTION key held down? The RAM under the BASIC ROM doesn't get tested if you don't.

 

Yes i did ok so no bad ram. Im not a tech so i'll have to wait to have it opened up is there a serial number maybe that would let me know if the board chips are socketed?

[Mr Oni]

forgot i swapped it this morning with a working 800xl so redoing tests

[Mr Oni]

forgot i swapped it this morning with a working 800xl so redoing tests

Still nothing

[Mr Oni]

figured out the break key is broke

[Vyper68]

figured out the break key is broke

 

If you tried the Break Key in the Self-Test it does not register and that is normal, that does not mean it is not working.

[Mr Oni]

 

If you tried the Break Key in the Self-Test it does not register and that is normal, that does not mean it is not working.

it wont stop a program

[Vyper68]

Do you have a spare POKEY chip you can swap in if your keyboard is not being read properly?

[1050]

it wont stop a program

And that depends on the program where it can be shut off

by design. BASIC has the break key working and will error

out when pressed while running something simple like

 

10 PRINT "hello world"

20 GOTO 10

 

RUN that and then press the break key. If it doesn't stop

that program then your break key really doesn't work.

[Mr Oni]

And that depends on the program where it can be shut off

by design. BASIC has the break key working and will error

out when pressed while running something simple like

 

10 PRINT "hello world"

20 GOTO 10

 

RUN that and then press the break key. If it doesn't stop

that program then your break key really doesn't work.

 

 

Thats the program i tested it with lol the only one i know.

[1050]

Ah, a programmer!

Positively no good then, resume with Vyper68 in post #14

and change out U24 and U25 for new 4051 chips as a

last ditch effort before moving on to keyboard jack

connection problems or mylar issues. It could be any

of those, possibly more, but we are getting there and

trying the most often to fail points to hopefully get

to the real issue asap.

[Mr Oni]

Ah, a programmer!

Positively no good then, resume with Vyper68 in post #14

and change out U24 and U25 for new 4051 chips as a

last ditch effort before moving on to keyboard jack

connection problems or mylar issues. It could be any

of those, possibly more, but we are getting there and

trying the most often to fail points to hopefully get

to the real issue asap.

i am not a tech so this isnt easy i shall purchase those chips first and then a new keyboard. i tried opening up the computer but it has a giant metal piece covering everything which im taking is the Rf shield. the cable on the keyboard says Rev C

Edited May 10, 2018 by Mr Oni

[1050]

Giant metal thing not much of a problem, it's two

pieces held together by tabs around the outside of

it. Use a needle nose pliers to straighten the tabs

and then lift top piece clear of bottom piece.

I seem to remember a couple of philips screws too.

 

Any problems just let us know in your time frame,

we are here to help.

[Vyper68]

i am not a tech so this isnt easy i shall purchase those chips first and then a new keyboard. i tried opening up the computer but it has a giant metal piece covering everything which im taking is the Rf shield. the cable on the keyboard says Rev C

 

I live in the UK and have PAL 800XL's so most of the chips on my Atari's are not in sockets which means a lot of desoldering - do you know if you motherboard is completely socketed now you know how to pop the RF shield off and have a neb inside?

[Guest]

if you mean "how do i know if an XL for sale is socketed?"

you don't. but you can have a reasonable guess.

 

 

look at label underside, where's your Atari made?

 

Taiwan: mainly soldered, socketed are likely less than 25%

Hong Kong: mainly socketed, soldered are likely less than 25%

Edited May 11, 2018 by Guest

[Mr Oni]

if you mean "how do i know if an XL for sale is socketed?"

you don't. but you can have a reasonable guess.

 

 

look at label underside, where's your Atari made?

 

Taiwan: mainly soldered, socketed are likely less than 25%

Hong Kong: mainly socketed, soldered are likely less than 25%

Taiwan

[Vyper68]

if you mean "how do i know if an XL for sale is socketed?"

you don't. but you can have a reasonable guess.

 

 

look at label underside, where's your Atari made?

 

Taiwan: mainly soldered, socketed are likely less than 25%

Hong Kong: mainly socketed, soldered are likely less than 25%

 

I was just thinking if the OP is not familiar with soldering and replacing the 4051 might be a bit intimidating and should maybe see if someone can repair his PCB. Just a thought...

BTW even though we live in England my brother is a Patriots fan and for my sins I’ve always been a Bears fan

[Guest]

 

I was just thinking if the OP is not familiar with soldering and replacing the 4051 might be a bit intimidating and should maybe see if someone can repair his PCB. Just a thought...

BTW even though we live in England my brother is a Patriots fan and for my sins I’ve always been a Bears fan

did that rivalry arise from super bowl XX by any chance?

 

i discovered Boston sports from Cheers on channel4 - early 1983

my son is Philly fan of almost 20 years, so he's quite happy that the Eagles finally won a title.

Edited May 11, 2018 by Guest

[Vyper68]

did that rivalry arise from super bowl XX by any chance?

 

i discovered Boston sports from Cheers on channel4 - early 1983

 

I remember watching NFL on Channel 4 in the early 80's - Those days watching Walter Payton and the "Refrigerator"