Death of an 800 ?

[+Ripdubski]

Two weeks ago I used my 800, bought new in 1980. It worked fine using a monitor out to composite cable. I got a new monitor to s-video cable for my 130XE. It was giving me some vertical stripes so I pulled out the 800 and tried the s-video cable on it. Black screen. Tried the composite cable on it that worked just 2 weeks ago. Black screen. Each time I left the computer on just long enough to hear the boot sound, worried about the PSU.

 

So, thoughts? PSU or 800 gone bad? Other troubleshooting? I guess I can try the RF out.

 

Thanks,

Wade

 

[ACML]

Did you have a cartridge plugged in? The reason I ask is that a mis-aligned cartridge or dirty connection in the cartridge slot can cause the black screen on power up. If so, remove cartridge and try again. If it works, you have a dirty cartridge slot of it is mis-aligned.

Edited February 12, 2014 by ACML

[+Ripdubski]

No cart installed. However, I did notice the last I used it the interlock didn't work - opening the lid while running did nothing. I did try opening and closing it when troubleshooting it.

[ACML]

No cart installed. However, I did notice the last I used it the interlock didn't work - opening the lid while running did nothing. I did try opening and closing it when troubleshooting it.

When you say "it did nothing", do you mean that it did not turn the computer off when the door was open (i.e. stays ON). Or did you mean that it won't allow it to power on. Given your description of the "black screen", I imagine its the former. As far as the switch, it could be that the plastic plunger is possibly binding or the little leaf spring in the interlock switch needs adjusting. Be carful, that leaf spring switch is tiny and once errantly launched into a carpet, it will be very hard to find (been there, done that).

 

Do you have an 810,1050 or other Atari item that uses the same 9VAC power supply? You could test that, but I'm sure you would have if that was available. You could check for the 9VAC using a multi-meter. As a more drastic next step you could reseat the ROM and RAM modules. If that fails, open up the machine and reseat the CPU board and if you want to go "all in", carefully reseat the ICs as one may have a continuity issue due to oxidation. A reseat may help it find a clean contact on that all important pin on chip "X"?

Edited February 12, 2014 by ACML

[russg]

No cart installed. However, I did notice the last I used it the interlock didn't work - opening the lid while running did nothing. I did try opening and closing it when troubleshooting it.

Take the interlock switch out and put a continuity wire in it's place. It is simple to do and now there's no problem with the lid having to be shut.

[+Ripdubski]

When you say "it did nothing", do you mean that it did not turn the computer off when the door was open (i.e. stays ON).

 

That. It did not turn off like it should have. I'll check the voltage on the PSU. I have a PS for a 1050, but I have to dig it out. When I say black screen - I see the video blink like its going to come on, but the screen is "almost black" afterward. Thanks for the help so far.

[ACML]

That. It did not turn off like it should have. I'll check the voltage on the PSU. I have a PS for a 1050, but I have to dig it out. When I say black screen - I see the video blink like its going to come on, but the screen is "almost black" afterward. Thanks for the help so far.

I think you have a good chance of getting it to work. These 800's are built tough and with good materials. They can take a lot of abuse and the electronics keep working.

Edited February 12, 2014 by ACML

[+Ripdubski]

Measured voltage from the PSU was 2.5v. Ill dig the 1050 one out and try it.

[candle]

just remember you should measure AC voltage, DC will show you all kind of crap

[russg]

That. It did not turn off like it should have. I'll check the voltage on the PSU. I have a PS for a 1050, but I have to dig it out. When I say black screen - I see the video blink like its going to come on, but the screen is "almost black" afterward. Thanks for the help so far.

There are five boards that make an 800 work. I've put the OS board in a slot other than the front slot and ruined the OS board. I'm sure you're not so dumb, I have a spare set of boards with which you can narrow

down a problem to one of the boards. main board, power board, OS board, memory board and personality (the rear slot).

Edited February 14, 2014 by russg

[+Ripdubski]

No, I haven't moved anything internal. I also haven't had a chance to get the 1050 PS out and retest. I will this weekend.

[BillC]

There are five boards that make an 800 work. I've put the OS board in a slot other than the front slot and ruined the OS board. I'm sure you're not so dumb, I have a spare set of boards with which you can narrow

down a problem to one of the boards. main board, power board, OS board, memory board and personality (the rear slot).

OS & personality board are one and the same. The internal rear board is the CPU board which also contains CTIA/GTIA & ANTIC

[russg]

OS & personality board are one and the same. The internal rear board is the CPU board which also contains CTIA/GTIA & ANTIC

Sorry. I consistently mess that up. At least, there are 5 internal boards. The external power supply makes an important sixth component, which Ripdubski will check this weekend. If he tested the external

brick at 2.5 v, it is definitely a candidate.