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Any ideas ? Apple II+ itself working, with connected disk drive no prompt/no boot

z80eu

Experienced Member
Joined
Feb 26, 2014
Messages
51
Location
Germany
I am out of ideas. I tried already to replace some typical faulty TTL chips on the Disk Controller itself (74LS174, 74LS132, 74LS259) and on the analog board of the drive (74LS125).
The Apple II+ itself is working (showing the prompt, typing in some BASIC statements working, beeps on powerup).
If I insert the Disk Controller card (connected to 1 drive), I can see only the Apple ][ logo, but no prompt. The Disk Drive is continously spinning (and do not stop), and I don't hear any head movements (with and without an inserted disk).
Control Break helps to get the (BASIC) prompt back, but the drive is still spinning and spinning and ...

Any suggestions what to measure or to replace ?
I do not have any spare drive nor any second Disk Controller card (to compare)...
 
I am out of ideas. I tried already to replace some typical faulty TTL chips on the Disk Controller itself (74LS174, 74LS132, 74LS259) and on the analog board of the drive (74LS125).
The Apple II+ itself is working (showing the prompt, typing in some BASIC statements working, beeps on powerup).
If I insert the Disk Controller card (connected to 1 drive), I can see only the Apple ][ logo, but no prompt. The Disk Drive is continously spinning (and do not stop), and I don't hear any head movements (with and without an inserted disk).
Control Break helps to get the (BASIC) prompt back, but the drive is still spinning and spinning and ...

Any suggestions what to measure or to replace ?
I do not have any spare drive nor any second Disk Controller card (to compare)...

Just checking...Have you tried more than one disk? If the disk is faulty it would give the symptoms you describe (I think).

Tez
 
Could it be bad RAM?

I think Mike Willegal has on his website a memory test program you can enter manually. Even with bad memory you can reset and go to ROM basic. Just depends on which memory is bad and what program you enter to run if you'll have problems.
 
Bad drive. I just went through 5 +'s and about 10 drives in the past two weeks. That symptom is a bad drive. You can try to clean the heads, etc. but I'd say try another drive.
 
Bad drive. I just went through 5 +'s and about 10 drives in the past two weeks. That symptom is a bad drive. You can try to clean the heads, etc. but I'd say try another drive.

It was the controller. Meanwhile I got another one, same drive, and it worked.
 
Bad drive. I just went through 5 +'s and about 10 drives in the past two weeks. That symptom is a bad drive. You can try to clean the heads, etc. but I'd say try another drive.

Luck of the draw. I went through my entire stash of Disk ]['s and controller cards a couple months ago and found a whole slew of bad controller cards, and one that was on it's way: It would get very hot! All but one drive turned out to be good after speed calibration. The remaining drive had a bad head, and a bad spindle motor, whatever that means.
 
Uln2003

Uln2003

Have you replaced the ULN2003 chip?

I am out of ideas. I tried already to replace some typical faulty TTL chips on the Disk Controller itself (74LS174, 74LS132, 74LS259) and on the analog board of the drive (74LS125).
The Apple II+ itself is working (showing the prompt, typing in some BASIC statements working, beeps on powerup).
If I insert the Disk Controller card (connected to 1 drive), I can see only the Apple ][ logo, but no prompt. The Disk Drive is continously spinning (and do not stop), and I don't hear any head movements (with and without an inserted disk).
Control Break helps to get the (BASIC) prompt back, but the drive is still spinning and spinning and ...

Any suggestions what to measure or to replace ?
I do not have any spare drive nor any second Disk Controller card (to compare)...
 
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