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johny_2k
August 24th, 2013, 04:22 AM
Hello guys,

I have one PC 200 and I am having some problems with it.
It did not boot with keyboard error... I cleaned up the computer and got pass this problem.
Than tried some 1.44MB diskettes with FreeDOS and DR-DOS but it did not boot, so I opened the floppy drive to clean up heads, and put some lubricant in the rail (by the way, this computer support 1.44 MB or only 720K ?)

While I was testing it without monitor, it seemed to wait the diskette, and after I pressed ENTER, it tried to access to floppy...nice.

So, I turned it off, moved to another room where I have a TV to connect the computer... turned it on, and then it started trowing the error "controller or disk faulty..." and beeping.

Do you think it is smoked? I mean, the floppy controller?
Can it be saved (the computer), what you think?

I appreciate any advice,
thanks.

Al Hartman
August 24th, 2013, 02:37 PM
I would make sure all the cables are properly seated, and if possible try connecting a known working disk drive to the cable just to isolate the problem to the disk drive or controller.

johny_2k
August 24th, 2013, 04:14 PM
This sinclair pc 200 has a single floppy only, no hard disk.
The controller is on onboard, there is only one flat cable to the floppy...
Thanks.

Al Hartman
August 24th, 2013, 04:20 PM
None of that dismisses what I recommended. If I were servicing your computer for the problem you described, I'd change the most likely culprit, which is the floppy drive you might have accidentally damaged while cleaning and lubricating it.

Al Hartman
August 24th, 2013, 04:24 PM
I did a simple Google search and found that the PC200 uses 720k diskettes, so it won't work with high density floppy drives or diskettes.

Al Hartman
August 24th, 2013, 06:21 PM
I usually keep that kind of opinion to myself. It doesn't do any good to insult someone. But, I admit, not everyone is cut out to diagnose and service equipment. I used to be a service tech for over 20 years until becoming inured on the job in 2006.

johny_2k
August 25th, 2013, 12:58 AM
I usually keep that kind of opinion to myself. It doesn't do any good to insult someone. But, I admit, not everyone is cut out to diagnose and service equipment. I used to be a service tech for over 20 years until becoming inured on the job in 2006.

Absolutely not feeling insulted, no worries.
I need every piece of advice one can give.
I mentioned the info about the floppy/single cable because you may not be familiar with the PC 200.

The floppy does not light up or move during boot, and the computer halts during the bios tests.
It worked just a few minutes before, when it asked for a valid boot floppy...

There its not much moving parts to play with...

Al Hartman
August 25th, 2013, 05:07 AM
This is why you have to try another floppy drive. Have you checked that all the cables are attached to the drive and logic board correctly?

TheChapajai
August 25th, 2013, 05:52 AM
I would try to change some of the capacitors. Resistors and IC's don't break on its own, capacitors die with time.
Good luck.

johny_2k
August 25th, 2013, 01:15 PM
This is why you have to try another floppy drive. Have you checked that all the cables are attached to the drive and logic board correctly?

Mr.,

You was right.
I was sceptical because after the original floppy failed, I tested with two others floppy drives I have here, and none worked.

I was afraid to do this, butt I finally got some courage and hooked up my HxC floppy emulator with a 720Kb image of FreeDOS to the Sinclair flat cable... And it booted!

So, it was really a floppy problem. Thanks Al and everyone that contributed.

Now remain a question... The floppy drives that did not work are necessary dead?

Al Hartman
August 25th, 2013, 01:35 PM
I would test them on another system before deciding they were dead. Remember the PC200 drive is definitely 720k. I don't know what the other two drives are.