Atari 1040 4MB RAM upgrade problems

[exxos]

As for the underside of the board, I do have some scratches. Would this cause a problem? What can I do to correct this?

It makes me want to ask the question , was the machine working in the first place ?

[Tomswork]

Just looking at the pictures there seams to be alot of tension on the socket. And alot of corrosion what type of flux are you using

Tom

[rubber_jonnie]

You really need to look at the Shifter. You have a row of bent pins on the left of the Shifter itself in your photo of the adapter board. Regardless of there being continuity, it is really bad practice to let chip legs get bent like that as they can actually be folded under the chip and not in the socket properly.

BTW I don't think they are scratches, more like pen marks from the factory. Try cleaning with IPA to see if they clean off, and if not check the track continuity with a multimeter.

[PhilC]

I agree with @rubber_jonnie , it lookslike at least 5 pins aren't in that socket correctly, so remove the shifter, straighten the pins and reinsert them.

[Tomswork]

@PhilC
@rubber_jonnie

Is the shifter socket on the motherboard a single contact or double wipe it looks like the adapter pins are pushing to the outside of the socket


Tom

[rubber_jonnie]

@PhilC
@rubber_jonnie

Is the shifter socket on the motherboard a single contact or double swipe it looks like the adapter pins are pushing to the outside of the socket


Tom

I think it's a double wipe socket, and I've never encountered a single wipe on an ST, even my 520ST. I agree, although the board appears correctly assembled, I think the pins are pushing outwards and it may be having an effect on the pin contact in the socket. It could even be going outside the outer wipe.

[PhilC]

It more than likely that the pins are bent inwards as I'm sure you guys have seen, so may be making contact but only by touch and not insertion.

[rubber_jonnie]

It more than likely that the pins are bent inwards as I'm sure you guys have seen, so may be making contact but only by touch and not insertion.

Are you referring to where the adapter plugs into the Shifter socket, or where the Shifter plugs into the adapter?

TBH I don't like the look of either and think both should be remedied prior to further troubleshooting, as the black screen with a border usually means no RAM detected.

I'd even be inclined to revert back to the onboard RAM to verify that the ST is actually working.

[exxos]

I'd even be inclined to revert back to the onboard RAM to verify that the ST is actually working.

I think that is probably a good idea, refit those uplifted resistors, remove the RAM board, no need to mess with the shifter board at all as it is just a breakout board anyway.

[PhilC]

@rubber_jonnie I was talking shifter chip into adaptor board

But agree, forget that and get it running without to see if it still works.