Atari 1040STf No Video

[lisalover1]

I recently picked up the remains of a 1040STf that had its PSU and floppy drive stripped out, so I set out on a mission to restore this poor baby. I picked up a new old-stock PSU from Best Electronics, a Gotek floppy emulator, and an ST Monitor Port-to-VGA cable. I finally got all three elements together to test the machine.

 

The good news is that both the Power and Drive LEDs light up and stay lit up. Additionally, the monitor definitely detects when the computer is on/off, as it gets some signal, but nothing actually ever appears on the screen. Nothing on the board looks out of place or missing, so I'm not sure what the issue could be here. Any advice for making this work again?

Edited October 12, 2019 by lisalover1

[ParanoidLittleMan]

What average user can do is to clean up it. Ensure good contacts - in case of Atari ST it means mostly reseating socketed chips (those square ones in first place), removing rust from pins by need. That must be done carefully, not to damage sockets, which are from stiff plastic. If that helps not, it will need someone with experience and equipment. And may need replacement of some component(s) .

Btw. the reason why nothing on screen is most likely that it fails at some stage of early HW initialisation.

[snarkdluG]

Maybe the computer works fine and that it is the monitor that can't handle 15Khz that the Atari sends out? I can't remember if it switch to monochrome instead in that case and the monitor works fine at higher resolution and double refresh rate. In that case the computer is indeed faulty.

[lisalover1]

8 hours ago, snarkdluG said:

Maybe the computer works fine and that it is the monitor that can't handle 15Khz that the Atari sends out? I can't remember if it switch to monochrome instead in that case and the monitor works fine at higher resolution and double refresh rate. In that case the computer is indeed faulty.

The cable I purchased says it can output 640x400 in monochrome, so I assume that means it should work with a 31KHz monitor.

[lisalover1]

10 hours ago, ParanoidLittleMan said:

What average user can do is to clean up it. Ensure good contacts - in case of Atari ST it means mostly reseating socketed chips (those square ones in first place), removing rust from pins by need. That must be done carefully, not to damage sockets, which are from stiff plastic. If that helps not, it will need someone with experience and equipment. And may need replacement of some component(s) .

Btw. the reason why nothing on screen is most likely that it fails at some stage of early HW initialisation.

Well, that's a shame - I was hoping I could get this working again by just dropping in some new parts, but I guess there was a reason this machine was gutted in the first place >~<

I've already given it a good clean and re-socketed the chips, so I'm running out of options.

[snarkdluG]

Get a test cartridge and try that. If nothing on screen then you could connect the Atari to another computer (PC, Mac, Commodore, Amiga, Atari) via the com port and a null modem cable (9600 8N1) and see if something is happening.