1541 problem

I need help was backing up my c64 cassettes to my 1541 and now all of a sudden the 1541 won't recognise any disks at all. :thumbsdown::thumbsdown::thumbsdown:
anyone got any ideas i really need help on this

If you read the error channel, what error does it come up with?

Tried a head clean?

Could the drive belt have snapped?

it says 74 drive not ready 00

the disk spins fine

Perhaps these might be of some help in narrowing things down for you

http://personalpages.tds.net/~rcarlsen/cbm/1541chip.txt

http://personalpages.tds.net/~rcarlsen/cbm/fix1541.txt

From an earlier phone convo we have ascertained that its either

1. Head Alignment
2. UA1(74LS14) and or UB1 (7406) logic failure

insofar as CBM 1541's I am some what dumb when it comes to these devices
---------------

Symptoms

Device Powers up OK

1. green light on
2. red light flash and then off

--------------------------------

Upon attempting to load a directory

Code:

---

LOAD"$",8

---

1541 drive enteres Error state (flashing red led)

quering the error channel -

Code:

---

10 OPEN 15,8,15
20 INPUT#15,EN,EM$,ET,ES
30 PRINT EN,EM$,ET,ES
40 CLOSE 15

RUN

---

result

Code:

---

74,DRIVE NOT READY,00 00

---

---------------------------------------

we then tried to initialize the drive, with a Disk Format, alas it cannot format, so we used the following code to initialize the Drive

Code:

---

OPEN15,8,15 <return>
PRINT#15,"I" <return>
CLOSE15 <return>

---

ends with same error of

Code:

---

74,DRIVE NOT READY,00 00

---

When we did the initialization the R/W Head moved back and forth to track 18 (middle of the disk)

But still no joy when trying to bring up or use any Floppy (same error)


We have discovered a secondary possibility of a logic faliure -

UA1 74LS14 LOGIC

Partial failure common cause of "FILE NOT FOUND" error. Total
failure: when drive powered up, red LED stays on and spindle motor
runs continuously (check also UB4, UC2, UC4, UC5, UC6, UD3, and UD5).

UB1 7406 (M53206P) LOGIC

Partial failure most common causing "SEARCHING FOR" (also check
UC3), or "DEVICE NOT PRESENT". Total failure: drive may power up
normally, but will not reset when the computer is turned on.


Drive Alignment

Quote:

---

Originally Posted by RayCarlsen

Drive misalignment is something that doesn't usually happen all at once.
It's normally a gradual process that begins with occasional disk errors (bad
disk or intentional errors from copy protection) while loading (red LED
flashing), failure to work with some programs, or excessive head chatter (the
drive getting "lost" and having to go back to track zero to "find" it's place
again.) Drives are forced out of alignment mostly while hot from use by copy
protected programs or disk errors that cause the head to chatter against the
track zero stop repeatedly. If the alignment is far enough off, you will get
"FILE NOT FOUND" and red LED flashing with all disks, and the drive may try
several times before "giving up". Note that misalignment will cause read
errors with known good disks but such a drive will probably still be able to
format a disk and read it back again. A disk formatted on a misaligned drive
will not read properly on a correctly aligned drive.

To properly realign a drive, you need special software. I use "1541/1571
Drive Alignment" by Free Spirit Software. The flipside of the program disk is
the alignment disk, and as such, should not be copied (a copy is only as good
as the drive that made it). The program provides a menu screen that indicates
what track you're on, drive speed, etc. You make adjustments to the drive
while watching the screen. The instructions even tell you how to load the
program when nothing else will load. You can -check- the alignment of the
drive without taking it apart, but of course realignment requires disassembly.
I always final-check my drives with several different program disks to verify
alignment... any commercial program disk can be used to do that.

Drive speed can drift over time, but it's rather rare to find it off far
enough to cause problems. Spindle speed (Note: some drives have no adjustment)
is reset with a small screwdriver adjustable control on a small PC board near
the spindle motor. On older belt-driven spindle motors, the belt may be
slipping. On all drives, the spindle collar (clamper) can get sticky and a
tiny bit of lube helps. Don't overdo lubrication. Excess oil will be thrown
off and could get on the disks.

Make sure the latch clamps the disk properly. Without a disk, move the
lever down and see if the spring presses the collar against the spindle to
clamp it securely. You can bend the tab down -slightly- (Newtronics drives
only) so it makes more firm contact if necessary. A slipping or stalling
disk will produce random read and write errors, a problem that's very hard
to track down. Some disks may work better than others. The DD ones without a
hub ring seem to slip more easily. HD disks should never be used in a 1541.

Bad (sticky) old grease on an ALPS drive can stall the spindle motor. If
that is suspected, you must remove the metal bar that the hub lock is mounted
on (two screws in the back) and take apart the clamper assembly by removing
the C clip. It has half a dozen assorted washers, a brass bushing and a
spring along with the plastic hub. Don't allow any of the spring-loaded parts
to fly off when you remove the C clip. These parts need to be cleaned with
solvent and put back together in the same order as before. A bit of moly lube
or light oil finishes the job. Make sure the hub clamper is centered on the
spindle before you fully tighten the rear screws.

---

So that all I can do to help m8y.

That's a huge coincidence Zetr0, I've just ordered a replacement 74LS14 & 2x7406's from futurelec to repair a board I have sat here.

Good place to start

TC ;)

@TC

To be fair, when there is coincidence, and when it normally involves something breaking, my friend Yorkie4 is generally the cause of such things! LOL

Bless 'em, he's been copying tape to disk over the last week, between 5 - 10 hours a day lol - I am surprised there's any sanity left LOL - not surpirsed the drive's developed a problem, it probably hasn't ever been used that hard in its life, let alone used in the last 20 years!

I was gonna say, that I had a few spare 74LS14's and 7406's - as I just went to check and while I have a few, there all SMD =(

looks like eBay again =)

http://home.comcast.net/~safeharborb.../cbm/1541.html
http://www.lemon64.com/forum/viewtop...5a9db7d3fb80fb
http://www.classiccmp.org/cini/pdf/r...%281285%29.pdf
http://www.c64scene.com/c64/?page_id=1230
http://www.sleepingelephant.com/v-we...7b778ffe35c457

Quote:

---

Originally Posted by Zetr0

@TC

To be fair, when there is coincidence, and when it normally involves something breaking, my friend Yorkie4 is generally the cause of such things! LOL

Bless 'em, he's been copying tape to disk over the last week, between 5 - 10 hours a day lol - I am surprised there's any sanity left LOL - not surpirsed the drive's developed a problem, it probably hasn't ever been used that hard in its life, let alone used in the last 20 years!

I was gonna say, that I had a few spare 74LS14's and 7406's - as I just went to check and while I have a few, there all SMD =(

looks like eBay again =)

---

cheeky git i never intentionally break anything i am just very very unlucky
and besides i only used the drive 3 days not a week and the next day it didn't work i am soooooo pithed

*ahem

I said, "over the last week"...... as in you got the drive Friday you sausage =)

And while I totally agree you never intentionally brake anything, you are cursed with some bad luck when it comes to somethings my friend =/

Me thinks its Karma.... you need to start pleasing Karma... and you might need to start reading a book about how to do that.... and no I am not talking about the karma sutra either... that is a totally different book, although I think this might help you woo the Karma lol....

BTW, I tried looking at Maplins for some 74LS14 and 7406's and they don't have them online... this means that they very unlikely to have them in-store... I will give them a buzz in the morning m8 and see if they do.... should they do, we can ninja out to pick 'em up in the afternoon =)