Author Topic: Have to repair a LIF 720Kbyte Diskette drive  (Read 522 times)

0 Members and 1 Guest are viewing this topic.

Offline xantia_99

  • Contributor
  • Posts: 28
Have to repair a LIF 720Kbyte Diskette drive
« on: June 19, 2021, 01:25:13 pm »
Hi
I have to repair/exchange a SONY LIF diskette drive MP-F52W-30 for a HP 16500A. As I know it's problem  to get everything to work with 16500A and these LIF diskette drive. However the other one is working and so does the analyzer.  A transistor  Q108 have gone on the PCB and probably more. But it seeks and rotate and can not find the system sector. The other drive work on the same cable. I can not find anything on Ebay or anywhere else just now.
So a working drive or a PCB would be perfect. I also look for the schematic. I have find a good manual with the PCB view but no spare parts och schematic. Many words have been said about HP 16500A I know them all..
Best Regards
Stephan

 
 

Offline dc101

  • Regular Contributor
  • *
  • Posts: 217
  • Country: us
Re: Have to repair a LIF 720Kbyte Diskette drive
« Reply #1 on: June 20, 2021, 12:10:19 am »
You might try looking into a floppy emulator http://hxc2001.free.fr/floppy_drive_emulator/#SALESPOINTS
It seems this is a fairly common use case for them.
 

Offline xantia_99

  • Contributor
  • Posts: 28
Re: Have to repair a LIF 720Kbyte Diskette drive
« Reply #2 on: June 20, 2021, 11:46:45 am »
Hi,
I will look into to that opportunity, thank you.
Have to consider the LIF consequences in this case,  if file names, LIF is not easy File system, or very simple compare with FAT,  and so on is a problem. HP 16500a in not on  comply official list, but test have been done with by users as I know until now.

I consider to convert to B version or measure the the transistor from the correct drive in the curve tracer. With that find a transistor good enough. I might do that in any case, time will solve it.

It's still an old system with problem with drive and strange behavior of cable location. That problem totally disappear for me if you keep the drives outside the box, CSR problem disappear.  I spent a lot of time with that.

I bought this unit for my memory of state analyse in the 80th   with 8085 and it end up with totally spending my  time on "possibilities" . I will not go to in every detail high voltage cable to close to the cover that made the unit reboot every time I put my hand on the top cover. But just push the cable more into center of the box it that problem disappeared.   And so on..

 


 
 

Offline xantia_99

  • Contributor
  • Posts: 28
Re: Have to repair a LIF 720Kbyte Diskette drive
« Reply #3 on: June 23, 2021, 12:42:36 pm »
Hi

Happy to say I have solved the problem, two  double common anod diode SOT-23 package on the PCB have replaced with 1n4148 discrete and now I boot the system from that drive.
Happy and with saved money and time. Have to go from temporary solution to a more clean solution to make it possible to put the drive in position.
   
Regards
Stephan


 

Offline amyk

  • Super Contributor
  • ***
  • Posts: 7443
Re: Have to repair a LIF 720Kbyte Diskette drive
« Reply #4 on: June 24, 2021, 12:36:24 am »
Hi,
I will look into to that opportunity, thank you.
Have to consider the LIF consequences in this case,  if file names, LIF is not easy File system, or very simple compare with FAT,  and so on is a problem. HP 16500a in not on  comply official list, but test have been done with by users as I know until now.
Floppy emulators don't care about the filesystem. They just present a disk image to the host as a series of sectors.
 

Offline xantia_99

  • Contributor
  • Posts: 28
Re: Have to repair a LIF 720Kbyte Diskette drive
« Reply #5 on: June 24, 2021, 11:07:21 am »
Hi
I might come back to emulator if I change to the B version and more traditional  diskette drive behavior and with that  different pin architecture .
The length of ribbon cable should not  exceed 0.5 meter from the spec from Sony diskette drive, but it's nearly 1 meter. That might explain CSR errors. Specially in one of drivers. The controller is about 1:1 to the nearest drive and 1:5 to the second drive. The controller in the middle 1:1 from the first drive.

That why I guess they changed to the B version very fast. Shorter ribbon cable and earth between active parts.

I just made a short thought how to get file in from dos format to LIF format and right file names on  the emulator, to get it so work with the controller. With lifutil.exe. Connect the emulator to a PC maybe. Just now I can not see that just now. The only way as I can see it is to copy files with the emulator in place on the  cable through the controller and software with the CPU from the second drive. It would work. But that needs a very special cable  I do not spend time on before B version.  Just now I do not spend time on that. I also have a lot of traditional diskette drives for B version, I believe use standard drives, however this HP so  ..

My setup yesterday work very well and boot the system. After a nice implementation instead of a lab version it do not work that great again. Sometimes. But I have to change one more dual diode I realized late yesterday. So I will reduce  cable and try to do a split up connector to scope and my  second logic analyzer. My intention just now, maybe I just get new error from that. I will see. Keep the original cable away from that.
 Hope to not spend to much time on this, I want to come back on track soon.

 
 

Offline xantia_99

  • Contributor
  • Posts: 28
Re: Have to repair a LIF 720Kbyte Diskette drive
« Reply #6 on: July 10, 2021, 02:18:41 pm »
Hi
After a lot of measurement with scope and logic analyzer and interments problem I found out one of the wire of five in the flexible folio  pcb is not working  to the upper head. So reading is not possible from that head. It's logic with the analyzer response. I also compared it with the working drive.
I have made many test setup with drive connected to new short cable and many other things with  a HP 54622D MSO . 
It's simple to resolve this problem with a working head. I could use this analyzer with one drive.

If someone do have  this parts I would be happy to hear about that.  Or otherwise I will change for B version and new problem or a emulated LIF drive other problem.

Best Regards
Stephan
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf