17 Nov
1997
17 Nov
'97
4:31 a.m.
<> > latest thing to come down the 'pike - it's all ASICs, custom
silicon,
<> > and surface mount stuff on wafer-thin boards. In short - not built
<> > to last. Nor is it designed to.
Surface mount offers compact and also better signal integrity for ultrafast
logic. There are many good reasons for surface mount that are in the realm
of quality improvement. Yes, it's take more skill to fix and some of the
parts are not easy to come by.
FYI in the industry there a few descriptions of part of the problem.
Good, fast, cheap, pick two.
Cost of repair exceeds value of unit. Fix/trash decision.
Many machine were made the way they were because technology of the time
balanced against cost were deciding factors.
Allison
17 Nov
17 Nov
6:16 a.m.
On Mon, 17 Nov 1997, Allison J Parent wrote:
<> > latest thing to come down the 'pike - it's all ASICs, custom
silicon,
<> > and surface mount stuff on wafer-thin boards. In short - not built
<> > to last. Nor is it designed to.
Surface mount offers compact and also better signal integrity for ultrafast
logic. There are many good reasons for surface mount that are in the realm
of quality improvement. Yes, it's take more skill to fix and some of the
IMHO, surface mount repairs are not that hard given the right tools - a
temperature-controlled soldering iron with a fine tip, fine silver-loaded
solder and a steady hand will suffice for most repairs. You don't _need_ a
hot-air rework station - such a unit will make the repairs faster, sure,
but not necessarily any better.
Don't try to remove the old component in one piece. Cut off the pins
(_carefully_), remove the 'body' and desolder the pins one at a time. Mind
you, I tend not to remove pin-through-hole devices in one piece unless I
know the device is rare and/or I am removing it to dump the contents. When
I repair something, suspect TTL devices get removed one pin at a time -
OK, so I may be replacing a few pounds worth of chips that were OK, but at
least the PCB will survive.
parts are not easy to come by.
FYI in the industry there a few descriptions of part of the problem.
Good, fast, cheap, pick two.
Cost of repair exceeds value of unit. Fix/trash decision.
What is a problem is when it was decided at the time of manufacture that
it was cheaper to replace than repair, so service manuals were never
available. Now, 10 years on, there may be no chance of finding a
replacement, so you have to repair. And repairing something without docs
is the second-worst job that I know (the worst is repairing something
with an incorrect/incomplete manual!)
Case in point : Zip drives. I won't use one because no service manual or
bit-level description of the disk is available. At some time in the future
all the drives will have died. And then there's no chance of ever reading
a zip disk again.
Allison
-tony
1:42 a.m.
Hi!
Successfully done on that fine pitch gull leads
with a common tiny
fine spring shaped to small L hook and heat each pin, pull on that
wire to flick some solder out and seperate that leads. Done that on
386sx chips and many IDE chipsets because they blow up and one I/O
chip on a recent P5 asus. (!) For J leaded types, I just melt too
much solder and lead that blob for fixing bad solder joints or
soldering in. To remove this I do not know unless you have hot air.
True that why I'm worried and maddening.
On Mon, 17 Nov 1997, Allison J Parent wrote:
Snip
Surface mount
offers compact and also better signal integrity for ultrafast
logic. There are many good reasons for surface mount that are in the realm
of quality improvement. Yes, it's take more skill to fix and some of the
IMHO, surface mount repairs are not that hard given the right tools - a
temperature-controlled soldering iron with a fine tip, fine silver-loaded
solder and a steady hand will suffice for most repairs. You don't _need_ a
hot-air rework station - such a unit will make the repairs faster, sure,
but not necessarily any better. Don't try to remove the old component in one
piece. Cut off the pins
(_carefully_), remove the 'body' and desolder the pins one at a time. Mind
you, I tend not to remove pin-through-hole devices in one piece unless I
know the device is rare and/or I am removing it to dump the contents. When
I repair something, suspect TTL devices get removed one pin at a time -
OK, so I may be replacing a few pounds worth of chips that were OK, but at
least the PCB will survive.
If it's rare part, save it unless you're SURE
it's totally blown by
funny behavior or cracked or smelly and bubbled. For common TTL IC's
I just snip 'em to save time and wear n tear on PCB. I do that same
to DRAM's.
> parts are not easy to come by.
Do it from
scrap boards for good oddball parts?!
FYI in the industry there a few descriptions of part of the problem.
Good, fast, cheap, pick two.
Cost of repair exceeds value of unit. Fix/trash decision.
What is a problem is when it was decided at the time of manufacture that
it was cheaper to replace than repair, so service manuals were never
available. Now, 10 years on, there may be no chance of finding a
replacement, so you have to repair. And repairing something without docs
is the second-worst job that I know (the worst is repairing something
with an incorrect/incomplete manual!) Case in point : Zip drives. I won't use one
because no service manual or
bit-level description of the disk is available. At some time in the future
all the drives will have died. And then there's no chance of ever reading
a zip disk again.
Then we use number to PRESS on Iomega to make it popular item and
provide specs or crack 'em the secrets. :) That technology is very
desiresble because those disks is so inexpensive and very durable
even the drives breaks. I can't stand thinking about LS-120!
Even we can tell them to improve on one problem because I already
ID'ed a problem that are killing those drives jarring those heads
when 4 pins hits home at ejection, Using floppy type ejection design
is better because it does not move the heads and use the fiction to
soften up the eject speed. Don't worry about the head, it retracts
completely out of the disk automatically.
This is what I like about the Zip IDE drives it's a right design like
the floppy drive machism. But I wished Iomega sell one in SCSI
version as well which means we have to press for it!
Troll
Allison
-tony 
7:07 a.m.
Due to massive amounts of caffeine & sleep deprivation, jpero(a)cgo.wave.ca
said:
[snip]
> Case in point : Zip drives. I won't use one
because no service manual or
> bit-level description of the disk is available. At some time in the future
> all the drives will have died. And then there's no chance of ever reading
> a zip disk again.
Then we use number to PRESS on Iomega to make it
popular item and
provide specs or crack 'em the secrets. :) ...
[snip]
This is what I like about the Zip IDE drives it's a
right design like
the floppy drive machism. But I wished Iomega sell one in SCSI
version as well which means we have to press for it!
The external SCSI Zip drive was the first one on the market!!! shortly
after, the parallel interface external followed... but it's only a kludged
SCSI I/F anyway... there's a "parallel to SCSI converter" in the drive, and
the software interface only sends SCSI commands thru the parallel port.
IIRC, the internal SCSI and internal IDE came at roughly the same time
(i.e. not too long ago).
I've had a SCSI Zip for 18 months now... but I digress.
Anyone know how to build a simple ACSI to SCSI converter so I can hook one
up to the DMA port on my Atari 1040ST????? ;-)
HTH,
"Merch"
--
Roger Merchberger | Why does Hershey's put nutritional
Programmer, NorthernWay | information on their candy bar wrappers
zmerch(a)northernway.net | when there's no nutritional value within?
3 a.m.
New subject: Trying here...for hd parts, they're old.
Hi,
Looking for either just board or whole drives with bad HDA but board
is considered good. Here's the list:
Seagate:
ST1201A
Conner:
CP30104, CP30174E
Question:
I have a board that does not match to any hds for conner:
It's stamped 06700-010-P3, Two ROM's INTF rom label: 6YT-039A and
DISK rom label: 6AB-039. This board only belongs to either late
2 models series that uses front jumper besides the LED connector
instead of seperate on-board jumper block. This board fits same way
like the CP30 and CP300 series 1" with motor hump held in place by 3
screws.
Maxtor:
7213A, LXT 213A
Western Digital
WDAC2200
If anyone have a used IDE hd to sell between 120 to 400mb real cheap
also please respond! All of those drives are strictly my use and
several are for bench work and plain use. I hate to use 40mb to
80mb which I have one of each. Will pay shipping. If some want to
disposed of that would be nice. Please email me to haggle but I
prefer cheap.
Thanks!
Troll
PS tried that on newsgroups last year with very poor results.
10:39 p.m.
On 17 Nov 97 at 16:07, Roger Merchberger wrote:
I've had a SCSI Zip for 18 months now... but I
digress.
Anyone know how to build a simple ACSI to SCSI converter so I can hook one
up to the DMA port on my Atari 1040ST????? ;-)
HTH,
"Merch"
--
Roger Merchberger | Why does Hershey's put nutritional
Programmer, NorthernWay | information on their candy bar wrappers
zmerch(a)northernway.net | when there's no nutritional value within?
I've been using a Syquest EZ 135 external SCSI as a sort of utility
DD on my doze mchns., my Mac+ and my ST for some time now
each with it's own 135 mb disk. Works great ( a few problems with
the Mac+ due to interleave speed) I use a Link2 for the Atari
interface, which also allows me to chain SCSI devices such as CD's
and scanners. Several of the Atari retailers carry them.
ciao larry
lwalkerN0spaM(a)interlog.com
9902
days inactive
9903
days old
5 comments
5 participants
participants (5)
-
allisonp＠world.std.com -
ard＠odin.phy.bris.ac.uk -
jpero＠cgo.wave.ca -
lwalker＠mail.interlog.com -
zmerch＠northernway.net