STe service blog / CA300779-001 Rev 5.1

[Steve]

Hi guys,

Just doing some servicing on a customers STe, here is my work on it...

Board images here

* Clean disk drive
* Apply motherboard bus resistor fixes
* Replace a few important capacitors, like reset circuit
* Add STe ghosting fix capacitor
* Replace mouse/joystick port
* clean/resolder video port
* General machine clean

The beginning...

1. begin.jpg

What do we have missing here?

2. oops what is missing.jpg

Bit rusty on the shield

3. rusty shield.jpg

Floppy needs a good clean and service!

4. dirty floppy.jpg

Time for a thorough clean

8. cleaning floppy.jpg

9. clean floppy.jpg

Let's replace the drive lube

5. old lube.jpg

10. new lube.jpg

Let's also re-cap the floppy

6. recap floppy 1.jpg

7. recap floppy 2.jpg

12. recap floppy motor.jpg

Shame, after all that the floppy is still having issues!

11. floppy still bad.jpg

The floppy heads are physically touching/scratching the disk, you can see the black mark worn on the head. The floppy drive is TOAST. So we are going to go for a FlashFloppy instead!

13. chewing disks.jpg

[Steve]

Time to re-cap the PSU! It is a DSP-508a

18. psu before recap.jpg

After the recap, looking good!

19. psu after recap.jpg

Time to test the voltage output under load!

21. test 5v.jpg

20. test 12v.jpg

[Steve]

Time to do some work on the motherboard, first the reset circuit and 470uf capacitor

15. re-cap reset circuit and 470uf.jpg

New 4700uf capacitor

PXL_20211014_183256157.jpg

Now time to swap out the 10k SILs for 2.2k

16. old sils gone.jpg

17. new sils in.jpg

Let's add the video ghosting fix while we're here

14. video ghosting fix.jpg

[Steve]

Time for some keyboard work

22. time to fix keyboard.jpg

Quite a bit of grunge to clean

23. a bit grungy.jpg

24. more grunge.jpg

Looks like the port area has a missing pad and broken trace

25. missing pcb pad trace.jpg

28. new port soldered and trace patched.jpg

Guess who put it back together, all 30 or so screws, then realised he forgot to reflow the solder on the mouse port... Well, it's done now.

PXL_20211014_182220876.jpg

30. new port.jpg

Let's give the keyboard and casing a good wash

26. time for a wash.jpg

27. wash case.jpg

Board nice and clean now

29. clean board.jpg

Those rubber feet look melted! Let's replace them

31. old feet.jpg

32. new feet.jpg

After everything I've done so far does everything still work I wonder? Let's do a quick test :)

33. does it still work.jpg

[Steve]

New HC type CPU

New Hotel drive

PXL_20211017_133852221.jpg

PXL_20211017_133858595.jpg

[PhilC]

@Steve what are you using for replacement feet?

repair looks good btw.

[rubber_jonnie]

What's going on with that FDD? I've never seen one with all the motor coils exposed like that, looks like it's missing the rotor or something.

[Steve]

What's going on with that FDD? I've never seen one with all the motor coils exposed like that, looks like it's missing the rotor or something.

They're not normally exposed, I was just replacing the capacitor which needed the cover taking off.

[rubber_jonnie]

What's going on with that FDD? I've never seen one with all the motor coils exposed like that, looks like it's missing the rotor or something.

They're not normally exposed, I was just replacing the capacitor which needed the cover taking off.

I get that, I'm used to seeing this:

IMG_20211014_152829.jpg

With the coils under the rotor (Silver disc) so that looks really strange to me. How is the spindle driven?

By cover did you mean the FDD case or the silver disk?

I'm just curious is all :)

[Steve]

@rubber_jonnie Check this out, same drive:
https://www.exxosforum.co.uk/atari/last/ ... /index.htm