520 STFM Floppy Issue

lilwashu · Post by **lilwashu** » Tue Jun 23, 2020 9:02 am

Thanks - the cable seems to be good based on a continuity test but I have one on order just in case, not looking forward to removing the header if it comes to that!

lilwashu · Post by **lilwashu** » Tue Jun 23, 2020 6:46 pm

Another update if anyone is interested - I put a bodge wire between L24 and pin 16 of the floppy connector and now the drive spins when a disk is inserted, it says "not responding" which is the same behaviour as this drive exhibited on my other ST. I will get some new capacitors for this drive and swap them over (Epson SMD-480L).

The trace that looked suspect was in fact fine and went to pin 6 of the connector.

Thanks for all the advice, I will update if I get it working!

lilwashu · Post by **lilwashu** » Tue Jul 21, 2020 3:24 pm

Closure on this one - recap on the floppy drive (the 6x10uf caps were in a very bad way) fixed it.

Post by **exxos** » Tue Jul 21, 2020 3:30 pm

Is it possible to post a image of what you changed ? It may help others in the future

lilwashu · Post by **lilwashu** » Tue Jul 21, 2020 5:24 pm

Sure - 6x 10uF caps are indicated on the "after" pic below by arrows in yellow and 1x 56uF cap in green. 4 of the 5 10uF caps on the lower board were surface mount which I twisted off, desoldered and replaced with bent 5mm through hole caps (RS part number 116-789). The 56uF through hole on the upper board was replaced with RS part number 572-211.

One of the 10uF caps on the lower board is hidden under a bit of the drive frame (large yellow arrow) - I didn't see it initially and didn't order enough caps, but the drive didn't work until I replaced it. The motor sounded "too fast" initially - when all the caps were replaced it sounded normal.

: IMG_1927.jpeg (145.01 KiB) Viewed 3361 times

DoG · Post by **DoG** » Tue Jul 21, 2020 6:58 pm

I have also done a recap of one of these drives last year which didn't work. I think I have some pics on it I can dig out. Maybe write a new thread about it so it's not buried in this thread.

Post by **exxos** » Tue Jul 21, 2020 9:42 pm

DoG wrote: ↑Tue Jul 21, 2020 6:58 pm I have also done a recap of one of these drives last year which didn't work. I think I have some pics on it I can dig out. Maybe write a new thread about it so it's not buried in this thread.

Sounds like a good idea, anything which solves a issue undoubtedly will help someone else in the future as well.

DoG · Post by **DoG** » Fri Jul 24, 2020 12:30 pm

exxos wrote: ↑Tue Jul 21, 2020 9:42 pm
DoG wrote: ↑Tue Jul 21, 2020 6:58 pm I have also done a recap of one of these drives last year which didn't work. I think I have some pics on it I can dig out. Maybe write a new thread about it so it's not buried in this thread.
Sounds like a good idea, anything which solves a issue undoubtedly will help someone else in the future as well.

This is now done. Find it here.

520 STFM Floppy Issue

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