8 Sep
2006
8 Sep
'06
7:41 p.m.
My latest acquisition came in today, a Mac IIci, that I wanted to use as an OS 6.08
machine with a Daystar Turbo 040 (68040/33) accelerator. Anyway after cleaning up the
system and installing the OS I put the card in and loaded the drivers and all was fine
(very fast booting). After about 15 minutes I had to reboot for driver update and the
system would just bomb during boot (about where the control panel for the Daystar card
would want to load). I took the card out and notice there was a capacitor missing on the
back with a nasty looking black burn mark. So I started looking around inside for the burn
metal part and notice I did not smell or see smoke or little capacitor parts (its a
surface mount with no numbers on it). Doing a little digging in my picture archive I
verified that the card which I have never used before (which is why I wanted a IIci since
it works in that model) was sent to me in this condition.
So what I want to know is how the thing functioned at all without the cap (burnt carbon
acted as a capacitor in some way)? and what caused it to stop working.
If anybody have an original Daystar Turbo 040 33Mhz card with the cache on a separate
board could you let me know (if possible) what value C54 s supposed to be? The cap looks
to be tied into one or two legs of the oscillator chip that controls the CPU (Ecliptek
EC1100 16.667Mhz 93-10).
I kind of want this working again since it will be a long time before I find another one
at a great price.
Thanks
TZ
8 Sep
8 Sep
10:24 p.m.
Teo Zenios wrote:
My latest acquisition came in today, a Mac IIci, that
I wanted to use as an OS 6.08 machine with a Daystar Turbo 040 (68040/33) accelerator.
Anyway after cleaning up the system and installing the OS I put the card in and loaded the
drivers and all was fine (very fast booting). After about 15 minutes I had to reboot for
driver update and the system would just bomb during boot (about where the control panel
for the Daystar card would want to load). I took the card out and notice there was a
capacitor missing on the back with a nasty looking black burn mark. So I started looking
around inside for the burn metal part and notice I did not smell or see smoke or little
capacitor parts (its a surface mount with no numbers on it). Doing a little digging in my
picture archive I verified that the card which I have never used before (which is why I
wanted a IIci since it works in that model) was sent to me in this condition.
So what I want to know is how the thing functioned at all without the cap (burnt carbon
acted as a capacitor in some way)? and what caused it to stop working.
If anybody have an original Daystar Turbo 040 33Mhz card with the cache on a separate
board could you let me know (if possible) what value C54 s supposed to be? The cap looks
to be tied into one or two legs of the oscillator chip that controls the CPU (Ecliptek
EC1100 16.667Mhz 93-10).
I kind of want this working again since it will be a long time before I find another one
at a great price.
Not sure of what you have (nor what *I* have!) :<
But, I found a couple of Daystar cards in my Mac pile.
Some are 030. I found an 040 that claims to be a "Turbo 040"
(written in the solder side foil layer on the corner of the
card furthest from the 040). The 040 seems to be a 33MHz part
so I will *assume* this is at least SIMILAR to what you're looking
for...
However, last used C seems to be C49 -- located on the solder
side between the CPU and the DIN connector. <frown> Perhaps
a different revision?
10:31 p.m.
----- Original Message -----
From: "Don" <THX1138 at dakotacom.net>
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
Sent: Saturday, September 09, 2006 1:24 AM
Subject: Re: Broken Mac Accelerator
Teo Zenios wrote:
> My latest acquisition came in today, a Mac IIci, that I wanted to use as
an OS
6.08 machine with a Daystar Turbo 040 (68040/33) accelerator. Anyway
after cleaning up the system and installing the OS I put the card in and
loaded the drivers and all was fine (very fast booting). After about 15
minutes I had to reboot for driver update and the system would just bomb
during boot (about where the control panel for the Daystar card would want
to load). I took the card out and notice there was a capacitor missing on
the back with a nasty looking black burn mark. So I started looking around
inside for the burn metal part and notice I did not smell or see smoke or
little capacitor parts (its a surface mount with no numbers on it). Doing a
little digging in my picture archive I verified that the card which I have
never used before (which is why I wanted a IIci since it works in that
model) was sent to me in this condition.
>
> So what I want to know is how the thing functioned at all without the
cap
(burnt carbon acted as a capacitor in some way)? and what caused it to
stop working.
>
> If anybody have an original Daystar Turbo 040 33Mhz card with the cache
on a
separate board could you let me know (if possible) what value C54 s
supposed to be? The cap looks to be tied into one or two legs of the
oscillator chip that controls the CPU (Ecliptek EC1100 16.667Mhz 93-10).
>
> I kind of want this working again since it will be a long time before I
find
another one at a great price.
Not sure of what you have (nor what *I* have!) :<
But, I found a couple of Daystar cards in my Mac pile.
Some are 030. I found an 040 that claims to be a "Turbo 040"
(written in the solder side foil layer on the corner of the
card furthest from the 040). The 040 seems to be a 33MHz part
so I will *assume* this is at least SIMILAR to what you're looking
for...
However, last used C seems to be C49 -- located on the solder
side between the CPU and the DIN connector. <frown> Perhaps
a different revision?
There was an early and a later board. The early part had the cache (128K I
believe) on a separate board that connected to the top backside), the later
parts had less chips but had no daughterboard since the cache was moved to
the main board.
The front of mine looks like this:
http://pomehouse.com/SE30/Cards/image/turbo040.jpg
Later version is this one:
http://www.applefritter.com/images/daystar_040_turbo_iici_front-2062_640x48…
There are 33Mhz and 40Mhz versions (68040), probably differing only in
oscillators used.
10:53 p.m.
Teo Zenios wrote:
Yes, this is what I have. Sorry! :(
However, last
used C seems to be C49 -- located on the solder
side between the CPU and the DIN connector. <frown> Perhaps
a different revision?
There was an early and a later board. The early part had the cache (128K I
believe) on a separate board that connected to the top backside), the later
parts had less chips but had no daughterboard since the cache was moved to
the main board.
The front of mine looks like this:
http://pomehouse.com/SE30/Cards/image/turbo040.jpg
Later version is this one:
http://www.applefritter.com/images/daystar_040_turbo_iici_front-2062_640x48… There are 33Mhz and 40Mhz versions (68040), probably
differing only in
oscillators used.
... and the speed grade of the CPU, no doubt!
Good luck!
9 Sep
9 Sep
2:55 a.m.
Teo Zenios wrote:
So what I want to know is how the thing functioned at
all without the cap (burnt carbon acted as a capacitor in some way)? and what caused it to
stop working.
Wel the carbon would act as a resistor. What you might find is that the
cap is just decoupling a supply line somewhere, in which case it can
probably lose one without too much worry.
Gordon.
1:29 p.m.
So what I want to know is how the thing functioned at all without the =
cap (burnt carbon acted as a capacitor in some way)? and what caused it =
That cap[acitor was probably a tantalum electrolytic (this being the type
normally known for exploding in this manner) and was probably a supply
decoupuling capacitor. That is, it was connected across the supply lines
to come component (say between +5V and ground), close to that component
to probide a local store of energy. Otherwise, the sudden current surge
when the device switehd could cause excessive voltage drop across the
supply traces to that component, and thus cause further problems.
That said, ther'es often a fair ammout of over-enginnering when it comes
to such capacitors. As I put it 'Decoupling capacitors are cheap, my time
in finding obscure glitches isn't'. So it's common to put at least one
per chip, at least on experimental/low-volume-production boards.
And therefore if one failes, it's likely the board will keep running.
I've had tantalum capacitors faile while a machine is in use, and the
machine just carries on.
to stop working.
Now that I don't know, but it may have nothing to do with that capacitor.
-tony
9:48 p.m.
On 9/10/06, Tony Duell <ard at p850ug1.demon.co.uk> wrote:
Perhaps there was some PCB damage under the exploded cap? We had
a tantalum cap (16uF?) blow on a COMBOARD that was installed in a
crowded BA-11... it looked like someone shot the board with a .22. The
boards on either side were damaged as well, but not perforated.
Since the OP described blackening, perhaps it might be worth a few
minutes to gently remove the residue (95% Isopropyl (1,2-propanol?)) and
a soft toothbrush should get most of the crud off - then check the traces
and see if there's any visible damage.
Even if that's not where the problem is, a gentle cleaning should hurt
anything.
-ethan
So what I want to know is how the thing functioned at all without the =
cap (burnt carbon acted as a capacitor in some way)? and what caused it =
That cap[acitor was probably a tantalum electrolytic (this being the type
normally known for exploding in this manner) and was probably a supply
decoupuling capacitor. to stop
working.
Now that I don't know, but it may have nothing to do with that capacitor.
11:07 p.m.
----- Original Message -----
From: "Ethan Dicks" <ethan.dicks at gmail.com>
To: "General Discussion: On-Topic and Off-Topic Posts"
<cctalk at classiccmp.org>
Sent: Sunday, September 10, 2006 12:48 AM
Subject: Re: Broken Mac Accelerator
capacitor.
On 9/10/06, Tony Duell <ard at
p850ug1.demon.co.uk> wrote:
> >
> > So what I want to know is how the thing functioned at all without the
=
> > cap (burnt carbon acted as a capacitor in
some way)? and what caused
it =
>
> That cap[acitor was probably a tantalum electrolytic (this being the
type
normally known
for exploding in this manner) and was probably a supply
decoupuling capacitor.
> > to stop working.
>
> Now that I don't know, but it may have nothing to do with that
Perhaps there was some PCB damage under the exploded cap? We had
a tantalum cap (16uF?) blow on a COMBOARD that was installed in a
crowded BA-11... it looked like someone shot the board with a .22. The
boards on either side were damaged as well, but not perforated.
Since the OP described blackening, perhaps it might be worth a few
minutes to gently remove the residue (95% Isopropyl (1,2-propanol?)) and
a soft toothbrush should get most of the crud off - then check the traces
and see if there's any visible damage.
Even if that's not where the problem is, a gentle cleaning should hurt
anything.
-ethan
I cleaned the burnt material off and all I see is the fiberglass weave
texture (the pads the cap were on are long gone). The cap was in the general
area of the processor (back side of the card) and it looks like atleast one
leg of the oscillator that controlled the circuit went to it. While there
are a bunch of tracks around the area I don't think any were directly
underneath the area that is damaged or it never would have worked at all.
The before shot is here:
http://home.neo.rr.com/unknownk/images/blown_cap.bmp
6678
days inactive
6679
days old
7 comments
5 participants
participants (5)
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ard＠p850ug1.demon.co.uk -
ethan.dicks＠gmail.com -
gordon＠gjcp.net -
teoz＠neo.rr.com -
THX1138＠dakotacom.net