Atari 1050 not working

[naujoks]

I just picked up an Atari 800XL and a 1050 disk drive.

The 800XL seems to work fine, but the 1050 isn't.

When powering up, the two diodes light up, the motor is spinning for a couple of seconds, then stops (the LED goes out), and then after a couple of seconds, the motor starts again for a couple of seconds, goes out etc.

I've opened up the drive and gave it a visual inspection, it looked reasonably clean. Solder joints all look good. I took out the socketed ICs, gave the legs a good clean with a glass fibre pen, put some deoxit in the socket (and on the connectors).

No difference though.

Any idea what could be wrong?

[cwilbar]

Most of the time with disk drives the issues are mechanical.  Make sure (with power off) that the head assembly slides back and forth on the rails fine.  Sometimes sitting for many years they get stuck.  clean the rails and lightly lubricate them.  make sure with the drive level in the open position that the spindle hub turns easily.  The grease in the bearings can dry up depending on time and storage conditions, making it difficult to spin the disk at the right speed.

 

Make sure to clean the heads with isopropyl  alcohol and a q-tip.

 

After you've checked that out, report back here with systems that persist.

 

[+Peter Rabitt]

A couple of questions,,,

1, Was the 1050 hooked up to the 800xl. Was SIO cable hook up.

2. Was there a disk/dos disk in the drive..

It sounds like the drive is looking for a disk...

 

Peter

 

[Mrshoujo]

The 1050 should have a Power On LED and a Busy light which on 1st switch on will light briefly then go off. And that's before you connect the 800XL and turn it on. It should not light up the Busy LED until the computer asks for data. So hopefully the drive isn't making the floppy mech run for no reason.

[Beeblebrox]

Also never have the drive powered on whilst plugging and unplugging the Sio cable (and of course the power). It can fry ICs. 

 

Aside suggestions above it could be a bad Ic. 

 

When you have the case off (be careful not to touch the large capacitors at the back) could you observe the behaviour of the read /write head on the tracks. On power up it should move forward and back slightly and then stop. Does it keep moving back and forward as the light activity led is going off and on? 

 

 

[naujoks]

I can confirm that the r/w head moves easily on its rails (so far it remains stationary though, no movement whatsoever).

Right now I don't have the 800XL connected to the drive.

When switching on the drive, it displays the described behaviour, regardless of whether there's a disk in the drive or not.

 

[naujoks]

Addition: I let the drive sit there for a while, and after 1 minute or so, the spinning up/down cycle stopped.

The drive won't load the disks I have (a couple of Infocom adventures): I'm powering on the 1050, pressing the Option key, power on the 800XL, let go of the option key (if I keep it pressed, the self test starts).

Incidentally, what is the default position of the drive ID switches?

[Paul Westphal]

Paul Alhart is my drive guru. 
p.alhart@verizon.net

[Beeblebrox]

And can you confirm at every stage since you have had it whislt you were plugging and unplugging both the power cables and sio cable the drive was definitely powered off? 

 

I suspect a bad IC or socket perhaps? Especially if you have cleaned various bits.

[erichenneke]

6 minutes ago, naujoks said:

I can confirm that the r/w head moves easily on its rails (so far it remains stationary though, no movement whatsoever).

Right now I don't have the 800XL connected to the drive.

When switching on the drive, it displays the described behaviour, regardless of whether there's a disk in the drive or not.

 

Try cleaning the head well with alcohol and Qtip, and then after it all dries out well, hook it up to the 800xl and place a disk in it and see what happens when you turn everything on.  Drive first, then the 800xl. 

[naujoks]

Yes, the drive was always powered off when unplugging/plugging in cables.

One IC had a bit of corrosion, I cleaned that up, the sockets seemed to be in good condition otherwise, even though they're only single wipe. I don't think my cleaning efforts have made anything worse.

[Beeblebrox]

Sure. Cleaning it certain can't hurt. 

 

Given it hasn't worked since you acquired it, there may well still be an IC that has been damaged in the way described by the actions of a previous owner. 

 

See how you get on after following the advice of others above. 

 

Also, the power supply for this drive...is it the original or an aftermarket one? Just making sure the drive is getting the correct power (from memory 9.5v 1.5a).

[erichenneke]

Both slider switches set to the left = drive 1

 

[Beeblebrox]

BTW just re-read your post above. So on power up the drive head doesn't move at all on the rails? AFAIK it should move back and forth once, then settle. If it isn't moving at all that isn't a good sign afaik

[naujoks]

I'm getting 10.8VAC from the original PSU, so probably the required 9VAC with load.

I don't think the drive has been tampered with before, it's probably just not been used in years, possibly decades.

[naujoks]

1 minute ago, Beeblebrox said:

BTW just re-read your post above. So on power up the drive head doesn't move at all on the rails? AFAIK it should move back and forth once, then settle. If it isn't moving at all that isn't a good sign afaik

Correct, the head doesn't move at all, but as mentioned, it moves easily when I push it manually.

[Beeblebrox]

Afaik on boot up it should always move back and forth and settle. And do the same when inserting a disk and flipping the latch down. If it doesn't I think it is an indication of a bad ic or maybe sensor. Someone else more clued up than me can elaborate. 

 

It doesn't matter if the drive hasn't been opened before for a good while as such re my mention of a previous owner maybe plugging and unplugging the sio cable whilst on. Apparently these drives ICs are very prone to such damage. 

 

 

Edited June 30, 2022 by Beeblebrox

[manterola]

Maybe the J connectors not connected correctly? Can you send us some pictures?

[Beeblebrox]

2 minutes ago, manterola said:

Maybe the J connectors not connected correctly? Can you send us some pictures?

@manterola good point. I vaguely recall having a 1050 drive I bought which transpired had the front right j connector connected around the wrong way. Man my memory is bad. 

[naujoks]

I'll send a picture in a bit. 

Meanwhile, can I swap some of the ICs? I have 6507 from an Atari 2600 which I could try. Can I burn a new ROM? I couldn't identify the type used.

[xrbrevin]

use a 2732 EPROM:

?

1050-revL.rom

[spookt]

IIRC pulsing/flashing drive activity light on power up is a logic failure. The electronics failed self test. Try reseating the ICs and after that it’s probably a swap out game with known good parts. 

[+DrVenkman]

If the drive isn’t going through head-seek on boot up, any of the ICs could be bad, or the 7805 might not be producing enough voltage/current. So check the output of both voltage regulators, consider a swap of the 6507. Might also be ROM or the FDC controller chip.

Good luck!

[TGB1718]

One check, with the power off, push the head gently away from the track 0 sensor, then power

on, the head should move towards the track 0 sensor and stop when it gets there.

 

If it looks like it's pushing past the sensor to the end stop, could be a faulty Track 0 sensor.

 

If no head movement then try some of the solutions above

 

[+Stephen]

As mentioned, the flashing light is an indication of self test failure.  If that is failing, the drive won't be running code, so it won't be trying to move the head or scan for track 0.  It's "crashing" before it can do anything.