checking floppy ... locked

[audioaddictz]

after recently repairing a friends emu ultra 6400 .. which had a power supply issue ive been given this emaxII to repair

ive had it open and had a look and there are no component failures that i can see

upon power up it shows on the lcd screen checking floppy . and that is where it stops

i hear no seeking on the floppy drive


am i correct to presume that its a dead floppy drive

here is a set of photos ive uploaded on my facebook

https://www.facebook.com/media/set/?set=a.10153080903654572.1073741864.573014571&type=1&l=0c4a58594e

[audioaddictz]

Tested another floppy drive today and its doing the same.

Floppy light comes on .. no seeking .. says checking floppy and there it stops

Any ideas folks

[M.]

sounds very much like a bad WD1772 (floppy controller chip).

[audioaddictz]

Anything I can do to find out...maybe remove clean and re seat the chip

[M.]

Yeah you could try that or just buy a new one. Furthermore I would check the PSU..

[audioaddictz]

Any idea where I might get a new one?

[M.]

....  

http://lmgtfy.com/?q=buy+wd1772


& ebay,...,...

[audioaddictz]

thanks i did google it myself ... i just was not sure if it was a chip that required programming prior to instillation and in that case i would need one programmed for the emax II  ... however i guess from your response that its just a generic chip and it should work right out the packet

none the less im going to try and clean it first ... and check all the other chips  for leg corrosion

[audioaddictz]

ive located that chip on the board as well .. and noticed its not in a socket .. so its not likely to be corroded legs

i really dont want to have to de-solder it unless i have to ... is there any way i can test this to be 100% that the chip has packed up

are there other things i should be checking first

[M.]

Hm, that's bad...

My E-mus had sockets. Well I repaired my 5 Emus and 2 had broken WD1772. I'm just a hobby tech so I don't know how to test it.

[audioaddictz]

done a spot of research on the chip

here is a data sheet if anyone needs it

http://www.milton.arachsys.com/nj71/pdf/Roland/wd177x.pdf

seems its been used in all sorts of gear not just the emax ...

The floppy disk controller (FDC) in the W-30 is a Western Digital WD1772, the same controller as used in the Atari ST, Ensoniq SQ80, the Commodore 1570/1571 and 1581 disk drives, the Acorn BBC and Master series computers, and Andre Fachat's CS/A65 6502-based homebrew computer system.


there are a few versions .. although from what i have read they are all backwards compatible


attached is a photo of my wd1772-ph  02-02

[audioaddictz]

found some diagnostic manuals for free

http://synthark.com/synthesizer-museum/emu-gallery/emulator-archive/manuals/

The diagnostic lights also lean towards floppy drive or controller chip .

So I'm ordering one from eBay tomorrow ...will let you guys know how it goes

[audioaddictz]

Parts arrived today... will most likely be doing the repair on Sunday...

Will post my results and photos

[audioaddictz]

Well i removed the old chip which was quite hard job .. with dual layer pcb ... wish it had been in a socket ...

well now i have a socket fitted on the board with a brand new WD1772-ph 02-02 installed

put the whole thing back together .. and the same issue ... checking floppy ..nothing

so i found another floppy drive ... which i used to test it with initially .. pluged it in ... went past checking floppy and onto checking scsi ... however it still did not boot ...

so im thinking there was an issue with the drive and the chip

found this pdf of jumper settings for various floppy drives

http://freaknet.org/asbesto/roba/diskettes-jumpers.pdf

so im going to make sure the drive i have is set to ID0

and have another go

wish me luck

[audioaddictz]

modified another drive to d0 and she lives ... will post photos later too