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General Category => Technical Support => Topic started by: Kris on 15:08, 02 May 21

Title: Strange CPC 6128 /drive behaviour
Post by: Kris on 15:08, 02 May 21
Hi all,


I have some trouble with a 6128: I change the drive belt of the drive and then run "RPM" soft and DSK test to calibrate the rotation speed. Both software don't report me the speed (no info, drive is running endlessly). I have tested the drive on an other CPC and it works (RPM show 302RPM which is acceptable).


So the issue is coming from the motherboard; I already check and reflow all welding point in the area of the FDC but no progress).
Any idea is welcome.


Thank you
Title: Re: Strange CPC 6128 /drive behaviour
Post by: Bryce on 15:13, 02 May 21
Either a broken connection on the flat cable or one or more of the driver IC's has failed.

Bryce.
 
Title: Re: Strange CPC 6128 /drive behaviour
Post by: Kris on 15:23, 02 May 21
I will change the flat cable to be sure.




EDIT: new flat cable installed: same result.


I tried a 3rd drive and it give the same result on this motherboard.
Title: Re: Strange CPC 6128 /drive behaviour
Post by: Bryce on 21:23, 02 May 21
The it's the driver IC's.

Bryce.
Title: Re: Strange CPC 6128 /drive behaviour
Post by: Kris on 21:51, 02 May 21
Which ones do you mean ?

Title: Re: Strange CPC 6128 /drive behaviour
Post by: Bryce on 10:07, 03 May 21
See attachment. If the drive isn't reacting to commands, the output drivers have a problem. If the drive reacts to commands but the computer reports an error, then the input drivers have a problem.

Bryce.


Title: Re: Strange CPC 6128 /drive behaviour
Post by: Kris on 10:26, 03 May 21
Hi Bryce,


Thanks for your feedback.
The drive is able to load a software without any issue, I will check the inputs driver
Title: Re: Strange CPC 6128 /drive behaviour
Post by: GUNHED on 19:23, 03 May 21
Thanks for your feedback.
The drive is able to load a software without any issue, I will check the inputs driver
If you can load from the drive then its communication seems to be fine.
Can it be that all hardware is fine, but the software has a problem?
Else I would suggest to check if the optical sensor for the index hole works.
Title: Re: Strange CPC 6128 /drive behaviour
Post by: Kris on 19:31, 03 May 21
Hi Gunhed,


I really think that the issue is coming from the motherboard of the CPC, the drive is fully working in an other keyboard (RPM & DSKtest are working fine).

Title: Re: Strange CPC 6128 /drive behaviour
Post by: GUNHED on 19:35, 03 May 21

Yes, you changed boards, I forgot. So, something inside the CPC.There are days we wish to have every IC in a socket.... Good luck!
Title: Re: Strange CPC 6128 /drive behaviour
Post by: ajcasado on 23:03, 03 May 21
See attachment. If the drive isn't reacting to commands, the output drivers have a problem. If the drive reacts to commands but the computer reports an error, then the input drivers have a problem.

Bryce.
Hi Bryce,

My external 3.5" floppy only works one sided. If I measure the voltage on //S1 is always ~0V. In Parados I have to select single sided head 1 for the drive to work. If I disconnect the /S1 signal then I have to select head 0 in Parados. With /S1 disconnected the floppy /S1 pin is at 5V and the CPC /S1 pin is at 0V. My CPC is a 664, but the driver IC's seems to be the same as in the 6128. In this case, should I have to replace IC206?
Title: Re: Strange CPC 6128 /drive behaviour
Post by: Bryce on 10:19, 04 May 21
Hi Bryce,

My external 3.5" floppy only works one sided. If I measure the voltage on //S1 is always ~0V. In Parados I have to select single sided head 1 for the drive to work. If I disconnect the /S1 signal then I have to select head 0 in Parados. With /S1 disconnected the floppy /S1 pin is at 5V and the CPC /S1 pin is at 0V. My CPC is a 664, but the driver IC's seems to be the same as in the 6128. In this case, should I have to replace IC206?

Possibly, but it's difficult to say without knowing exactly the type of 3.5in drive and what mods have been done. It could be a drive problem too.

Bryce.
Title: Re: Strange CPC 6128 /drive behaviour
Post by: ajcasado on 11:01, 04 May 21
Possibly, but it's difficult to say without knowing exactly the type of 3.5in drive and what mods have been done. It could be a drive problem too.

Bryce.

It's a NEC FDH1231H with the READY signal mod (http://www.cpcwiki.eu/index.php/Modify_PC_floppy_drives (http://www.cpcwiki.eu/index.php/Modify_PC_floppy_drives))

I also have a Mitsumi D359T6, but the PCB is different from the one in the photo of the wiki and I cannot find the DCH/RDY bridge so I tested it with the READY signal solution from http://www.cpcwiki.eu/index.php/Guide_on_how_to_connect_a_3.5%22_drive_to_a_CPC6128/664 (http://www.cpcwiki.eu/index.php/Guide_on_how_to_connect_a_3.5%22_drive_to_a_CPC6128/664), this one behaves in the same way  with the double side issue.