Amiga Internal Floppy Drive Repair (Panasonic Model JU-253-043P)

[@sergey155la3]

At the time I fixed my JU-253, the other small electrolytic cap on the bottom PCB had been also totally exhausted (showed clear signs of capacitor rot). Here, this one didn't look bad, but (given that contemporary Panasonic SMD electrolytics are known to age quite bad anyway) maybe it would be worth replacing that one as well.

[@ms-ex8em]

why cant microcomputers format floppy disks to the full one megabyte (1024kb)???? including chinon sony and panasonic etc ? its a bit strange and weird though, is it because some of the data if kept for filing systems etc?? thanx.....

[@DavePoo2]

The Amiga operating system (AmigaDOS) formats each side of a disk into 80 tracks of fixed width. These tracks appear in concentric circles around the center of the disk. Each track of each side in combination (e.g., track 1 top and track 1 bottom) is called a cylinder. Each track can be divided into 11 sectors. Every sector can store 512 bytes (512 characters). If you multiply the values presented here, you'll find that an Amiga disk can hold about 880k. Since IK corresponds to 1,024 bytes, dividing 901,120 bytes by 1,024 gives us 880K. To this figure we must add another 28K for directories and the File Allocation Table (FAT). [From "Amiga Disk Drives: inside & Out"]

[@mart1nandersson]

Great video Dave! This is the second time that you have delivered gold for me. The first time was your PSU PCB design that I have used 3-4 times to convert dead PSUs and now you helped me out with the mystery on how to open these crappy drives. The one I got bundled with an A1200 had the exact same cap leakage. Keep up the good work!

[@DavePoo2]

Thanks. This drive does actually work for me now, but it still has a few problems with some disks, which I've never had the time to work out, it may have an alignment problem or something. But hey, it loads Turrican, so it's a win. Glad you are getting those PSU's converted. I sleep soundly at night knowing there is a meanwell PSU powering my Amiga's. I've used the PSU's a lot now, and done many hours of live streaming on the Amiga using those PSU's.

[@ralfr.5974]

Great Video👍🏻

[@giuseppelavecchia775]

Hai fatto bene a non rimettere il condensatore originale,quello standard e' piu longevo e più sicuro,ottimo video

[@ChristopherNelson2k]

I've been poking at a Panasonic JU-257 for some time this eve trying to figure out how to get the top tray off. Thanks for showing the secret sauce on this!

[@DavePoo2]

Yeah, the video is edited, but it took me a while to figure it out.

[@methanoid]

Hi, what do you call those over goggle things. I already wear glasses for being long sighted (or magnifying) and often have to put a 2nd pair over to do close work !!

[@DavePoo2]

I'm wearing these www.amazon.co.uk/gp/product/B07JCFLSWP, they are very cheap but are actually very good, with 2 different magnifications. I don't wear glasses but i was wearing these over a pair of safety glasses when i was removing the cap (as sometimes the cap can pop from the heat) .

[@methanoid]

@@DavePoo2 thank you 🙂

[@andrewminion3138]

Hi, what capacitor do I buy for it, mine has the same issue. Thanks from Andrew

[@mart1nandersson]

You need a 10uF 35V electrolytic capacitor. You can go higher on the voltage. I used a 50V cap that I had over after recapping an A1200 (EEHZA1H100R) and it had the exact same footprint.