8 Nov
2018
8 Nov
'18
10:19 a.m.
I've got a NeXTstation Turbo and a MegaPixel display; the computer boots
fine, but seems to complain of a failing hard drive.
The monitor works okay; slight burn in, but otherwise looks okay in terms
of the phosphor. However, something seems to be wonky with the horizontal
scan...the left edge is very wobbly.
Pictures here: https://imgur.com/a/azWHVuB
Before I open this up, does anyone have any suggestions on where to start?
I didn't see a NeXT section on Bitsavers.
I am aware of the dangers of CRTs and will be sure to discharge the anode;
I've worked on a few MDA monitors before.
Thanks!
Kyle
P.S. From the hard disk error message, would you agree it's failing? Would
this indicate total failure is imminent?
8 Nov
8 Nov
10:53 a.m.
On 2018-11-08 1:19 p.m., Kyle Owen via cctalk wrote:
I've got a NeXTstation Turbo and a MegaPixel
display; the computer boots
fine, but seems to complain of a failing hard drive.
...
P.S. From the hard disk error message, would you agree it's failing? Would
this indicate total failure is imminent?
I don't know how "imminent", but "inevitable" to be sure. Consider
a
SCSI2SD replacement? Perhaps a good moment to image the existing system.
--Toby
11:08 a.m.
The monitor works okay; slight burn in, but otherwise
looks okay in terms
of the phosphor. However, something seems to be wonky with the horizontal
scan...the left edge is very wobbly.
Replace all electrolytic caps with new Panasonic of Nichicon 105 degree
caps from a source like Digikey, Mouser, Newark or AVNet.
So... I've heard a lot of NeXT monitors get dim over time. There is a tool
for rejuvinating CRTs. I wondere if it would work rejuvinating NeXT
monitor to bring back brightness.
I am aware of the dangers of CRTs and will be sure to
discharge the anode;
I've worked on a few MDA monitors before.
Definitely. Some monitor chassis self discharge via a resistor, so if you
short anode to ground and don't see anything that is why.
4:35 p.m.
On 11/8/18 10:08 AM, Ethan via cctalk wrote:
My recollection is that the NeXT monitors left their heater (filament)
on all the time, when the computer was otherwise off. This causes the
cathode emission to decay over time.? Some of the rejuvenation devices
work by simply raising the heater voltage. The others work by
temporarily raising the heater voltage while using a high voltage
between cathode and CRT to try to reform the cathodes. I don't have any
experience in using these with the NeXT monitors, but the first method
is likely to shorten the filament life even further.? If the CRT is
"gassy", not much can be done.
I would definitely image the drive before it deteriorates any further.?
Be careful about using the 'dd' command with a 'bs' other than the
sector size of the disk.? Since the drive already has bad sectors, using
the "conv=noerror,sync" option has some unexpected side-effects when
bs>sector size.? See http://www.noah.org/wiki/Dd_-_Destroyer_of_Disks
under "Copy a drive to an image file"
Jerry
The monitor
works okay; slight burn in, but otherwise looks okay in
terms
of the phosphor. However, something seems to be wonky with the
horizontal
scan...the left edge is very wobbly.
Replace all electrolytic caps with new Panasonic of Nichicon 105
degree caps from a source like Digikey, Mouser, Newark or AVNet.
So... I've heard a lot of NeXT monitors get dim over time. There is a
tool for rejuvinating CRTs. I wondere if it would work rejuvinating
NeXT monitor to bring back brightness.
9 Nov
9 Nov
10 a.m.
I don't know a lot about these but I heard you should just replace all of
the caps, even things that look like they might be caps, with the largest
caps you can find. Just stuff them in there. You don't need solder, just
use a glue gun. There is a pretty cool suction cup in there you can use to
hold a hanging planter, etc.
On Thu, Nov 8, 2018 at 10:20 AM Kyle Owen via cctalk <cctalk at classiccmp.org>
wrote:
I've got a NeXTstation Turbo and a MegaPixel
display; the computer boots
fine, but seems to complain of a failing hard drive.
The monitor works okay; slight burn in, but otherwise looks okay in terms
of the phosphor. However, something seems to be wonky with the horizontal
scan...the left edge is very wobbly.
Pictures here: https://imgur.com/a/azWHVuB
Before I open this up, does anyone have any suggestions on where to start?
I didn't see a NeXT section on Bitsavers.
I am aware of the dangers of CRTs and will be sure to discharge the anode;
I've worked on a few MDA monitors before.
Thanks!
Kyle
P.S. From the hard disk error message, would you agree it's failing? Would
this indicate total failure is imminent?
3:14 p.m.
On 2018-11-09 10:00 a.m., Bill Degnan via cctalk wrote:
I don't know a lot about these but I heard you
should just replace all of
the caps, even things that look like they might be caps, with the largest
caps you can find. Just stuff them in there. You don't need solder, just
use a glue gun. There is a pretty cool suction cup in there you can use to
hold a hanging planter, etc.
I LOL'd, but consider this:
https://www.ebay.com/itm/Turbo-Grafx-16-console-repair-mods-full-ceramic-ca…
(hat tip to @Wohali)
On Thu, Nov 8, 2018 at 10:20 AM Kyle Owen via cctalk <cctalk at classiccmp.org>
wrote:
> I've got a NeXTstation Turbo and a MegaPixel display; the computer boots
> fine, but seems to complain of a failing hard drive.
> ...
2083
days inactive
2084
days old
5 comments
5 participants
participants (5)
-
billdegnan＠gmail.com -
ethan＠757.org -
jsw＠ieee.org -
kylevowen＠gmail.com -
toby＠telegraphics.com.au