[Atari SM124 image problem]

There should be one on the top right, pretty much right under the picture tube. It's almost impossible to adjust with the monitor assembled and switched on.

[Atari SM124 image problem]

Yes. There actually is a pot for horizontal hold on the PCB. Adjusting it fixed image. The problem comes back after a while though. Maybe the pot needs cleaning or replacing. Either way, the problem is connected with that pot.

[Atari 1040 STE won't sync with Commodore 1084 monitor]

Yes, everything is PAL.

I tried adjusting the H-HOLD pot R225, but it didn't fix it.

When connecting an Amstrad CPC, I can see the picture, but it's distorted and shaking about. When connecting the Atari ST, bascially nothing is visible on the screen except a few faint lines.

What could the reason be?

[Atari 1040 STE won't sync with Commodore 1084 monitor]

Unfortunately this didn't work either.

Just to test it further, I connected my Amstrad 6128 to the monitor, also using the SCART adapter, but it too doesn't sync.

You can see it would only need a touch adjustment of the horizontal hold.

I wonder if there's a pot to adjust on the inside?

[Atari 1040 STE won't sync with Commodore 1084 monitor]

I got a Commodore 1084-D1 monitor which I'm trying to get to work with my 1040 STE, but it won't sync.

The monitor has a 9 pin d sub port and I have a 9 dsub to SCART adapter for it. I have a monitor cable with a SCART plug.

I tried to make my own cable (RGB to RGB, GND to GND, Atari pin 2 (sync) to 1084 pin 7), but it's the same result, just distortion on the screen.

All the other computers I've thrown at the 1084 work (C64, C128, VIC-20, Amiga, various arcade boards), but not the Atari. Am I missing something here or is it not supposed to work?

[Transferring large files to Megafile]

Awesome, thanks!

By the way, is there a convenient way to extract individual files from .ST disk images?

[Transferring large files to Megafile]

What's the best way to transfer large files (ie larger than 800kB) to a Megafile HD with an Atari ST?

I have a Gotek floppy, but it too only can do disks up to 800kB large.

Also, how can I transfer individual files? Disk images in .ST is no problem, of course. But how to transfer .PRG files, say?

[Atari SM124 image problem]

The image looks like on the attached picture.

It's flickering, like as if there's a sync issue. I note that the picture is spread out on the entire horizontal width, which is not supposed to be the case, of course.

I recapped the board and neck board, without any difference. The board is looking clean otherwise, with none of the nasty glue spread out, which I've seen before on other monitors.

There doesn't seem to be any pot to adjust H or V sync, and the other pots don't seem to have anything to do with this problem. Many of them are stupidly placed underneath the tube.

I haven't found a place where to check B+ and I also don't know how many V it's supposed to be.

Any ideas what I could try?

[Atari 1040 STE disk drive problem]

I put the drive on top of my PC, where it's being warmed up to about 40 degrees.

I put the drive in the STE and it starts right away. It's all SMD parts on the board, apart from the connectors. I'll see if I can see anything suspicious.

[Atari 1040 STE disk drive problem]

I tried the other STE's drive in the one I'm having difficulties with, but I also tried the faulty disk drive in the working STE, where the drive also didn't work.

It's strange though: when the computer has been on for 15 minutes or so, the disk drive is working without any problems.

Which part needs time to "warm up" and why?

[Atari 1040 STE disk drive problem]

I have a problem with the disk drive in my 1040 STE.

On startup, it spins up alright, but the head just jerks back and forth 1mm.

When I move the head towards the inside by hand, on startup the drive moves it to the outside but it doesn't move from there. I cleaned and relubricated the spiral thingy.

There are two caps on the PCB which looked dodgy and I replaced those.

While playing around with it, the drive suddenly was working and I thought all's well, only for it to stop working again next time I started the computer.

The drive is a Sony MFD110-003.

I put in a known working drive from a different STE, and that's working just fine.

Any ideas what I could try?

[Atari 1050 doesn't throw out disks]

I have an 1050 which doesn't eject the disks when turning the knob.

There's this little metal notch (see pic) which, when pressing on it, makes the disk shoot out, so it appears there's enough tension on the spring.

Is there something else I can adjust or lubrify to make the mechanism work as intended?

[Atari 810 doesn't load]

The trouble is that the startup sequence doesn't complete anymore.

When switching on the drive now, it doesn't stop spinning, even without a disk inserted. And the LEDs don't come off anymore.

[Atari 810 doesn't load]

So I found out that the 810 does not spin the disk when one is inserted.

I did notice that ID 1 was not correctly selected (I wasn't very clever in checking).

Once ID 1 was selected, the drive now boots up when switching on the computer

Initially, it was loading a disk fine, when all of a sudden the head wanted to go to the outermost track and was rattling around there.

When I switched the drive off and back on, the head now remains there (or moves there if I pushed it back inwards before switching on), the drive is spinning and both LEDs are lit.

So now something actually properly broke?

[Atari 810 doesn't load]

I don't know the behaviour of these drives, it's my first one, as mentioned.

But isn't it true that when the flap gets closed and a disk is inserted, it starts spinning it immediately, independent on whether the write protect tab is on or off?

Also, if I half way insert a disk half way, so that the sensor is blocked, the drive never spins up, or does it?

[Atari 810 doesn't load]

That can't be it, the disk normally starts spinning when the flap gets closed doesn't it? The write protector sensor shines a light through the hole and the light gets detected if there's a hole or if there isn't. How could the same detector sense if the flap gets closed?

Are the schematics available somewhere?

[Atari 810 doesn't load]

I'm using the original power supply and I'm getting the correct voltage out of it.

I still can't figure out how the drive knows that the flap has been closed.

[Atari 810 doesn't load]

I've tried it with an 800 and an 800XL. Both are known to have working SIO ports.

Presumably the disk should spin even without a computer attached?

ID 1 is selected and the left SIO port is used. The SIO cable is known to work.

The 810 version I have is with the flap in the front, not the lever.

[Atari 810 doesn't load]

I received an Atari 810 - my first one!

It's not loading any disks.

Boot up sequence seems to be fine: disk spinning for about 6 secs, head moving in and out and in, LEDs lit during that time.

When inserting a disk, I'm expecting it to spin, but it does not.

When switching on the computer, nothing happens, no boot error or anything, it's as if the computer doesn't even know the drive is there.

I clean and deoxit'ed all socketed ICs and connectors; there's two connectors towards the front of the drive, one seems to be responsible for the write protected check and the other one for disk inserted, maybe? How does the drive detect that the lid is closed?

I THINK I'm on the right track when I think the drive should spin up when the hatch is closed and a disk is inserted, correct me if not.

Any ideas what I could test are much appreciated! I have MM and scope at the ready.

[Atari 1050 no spindle motor]

So to draw a line under all this, the latest batch of L7812CVs arrived today, I tested them with the light bulb and measure 10.78V, which is good enough, I suppose. I'm sure it would work in the drive.

[Atari 1050 no spindle motor]

Yes Sir, that's exactly what I will do.

And I will not think about the hours we wasted on this thing, when the only thing it needed was a working 7812. Well, and one wrongly oriented cap.

I will also not think about why the previous owner felt he needed to replace the power regulators. He could have had a working 1050, if his 7812 replacement had worked.

But anyway, thanks for all the help again!

[Atari 1050 no spindle motor]

I bit the bullet and got some actual LM7812. They tested at 11.30V and they work in the 1050.

I don't know if they're new or new old stock. They were expensive though, one for 3€ a pop, around 10x as much as a L7812CV, but at least they work.

I have one finaly batch of L7812CV coming next week. If those test faulty as well, I don't know what to do.

[Atari 1050 no spindle motor]

No, that's not it. I set the amp limit to 1A. It only shows this when the PSU isn't set to put out power.

Also don't forget the regulators also don't work when in the 1050. I also put one of them in without prior testing, just in case the testing should damage them somehow.

So, yes, I didn't have a single one that would put out even close to 12V. Remember how I tested a 7815 and that worked to expectations?

This can't just be a case of bad luck, not 16 times. There must be more people who have difficulties with non working 7812s, no?

[Atari 1050 no spindle motor]

Ok there's something very wrong here.

I got 10 more LM7812CVs, and none of them give the desired result, all hovering around 3.8V, going down very quickly (because of the lack of cooling, presumably; I only leave them on for a couple of seconds or so).

I've tested them with the bench PSU and the method outlined above.

In the drive they fail as well.

Attached is a picture of my test setup, just so that you can see I'm not doing anything stupid. There are no shorts between any of the legs.

I've tried 16 7812s, from 4 different manufacturers. What the hell is going on?

[Atari 1050 no spindle motor]

LM7812 are hard to kill or L7812CVs?

I didn't have the luxury of having the original LM7812 in the non working drive.