Very Computer

Hi!

Ok, this is weird: I installed a new hard drive, and now my Amiga
4000/040 runs perfectly for about 15 minutes, then it freezes up. When
I reboot, it gives me an $0000000B Guru and goes into an indefinite
reboot. However, if I keep the case of, it runs fine. Sounds like a
heat problem, right? But how do I fix it? The power supply fan seems
to be working, and the new drive isn't running hot. This problem never
happened in the 4 odd years I've had this computer...

Any help would be *greatly* appreciated....

   Marc Atkin            //
U of Massachusetts      //                " Goosnargh. "
   at Amherst       \\ //

works with the case off!? (help!)

Quote:>Hi!
>Ok, this is weird: I installed a new hard drive, and now my Amiga
>4000/040 runs perfectly for about 15 minutes, then it freezes up. When
>I reboot, it gives me an $0000000B Guru and goes into an indefinite
>reboot. However, if I keep the case of, it runs fine. Sounds like a
>heat problem, right? But how do I fix it? The power supply fan seems
>to be working, and the new drive isn't running hot. This problem never
>happened in the 4 odd years I've had this computer...

 See if you can find a cardboard box and cut out a piece to fit the top on
your system(and the sides too), now cut out another hole around where the CPU
slot is and direct the air from a fan into it.  Now start up your system and
see if it keeps working.

 The object is to get the air circulating within the system.

 If it keeps working then you may need to get a fan card from a clone
dealer(these plug into the ISA slot(for power only) and help keep the air
circulating inside your system), the stock power supply fan may not be up to
the task of keeping the system cool any longer.

 While you're at it, check and see if there is any lint or other junk blocking
the PS fan.

 The fan may be wearing out as well(yes, it does happen).

Quote:>Any help would be *greatly* appreciated....
>   Marc Atkin            //

I have a mind Like A Steel Trap - Rusty And Illegal In 37 States

|  Ok, this is weird: I installed a new hard drive, and now my Amiga
|  4000/040 runs perfectly for about 15 minutes, then it freezes up. When
|  I reboot, it gives me an $0000000B Guru and goes into an indefinite
|  reboot. However, if I keep the case of, it runs fine. Sounds like a
|  heat problem, right? But how do I fix it? The power supply fan seems
|  to be working, and the new drive isn't running hot. This problem never
|  happened in the 4 odd years I've had this computer...
|
|  Any help would be *greatly* appreciated....

Check the air circulation inside the computer, look at the cables in
particular. The 68040 generates a lot of heat. I have had two IDE disks
(3600 and 4500 rpm) in my A4000/040 and now a 7200 rpm SCSI disk without
heat problems myself. I also have one Z-II and two Z-III cards.
If you still have problems, you can try a '040 CPU fan.

-John

--
John Olav Skog?s

: works with the case off!? (help!)
: >Hi!
:
: >Ok, this is weird: I installed a new hard drive, and now my Amiga
: >4000/040 runs perfectly for about 15 minutes, then it freezes up. When
: >I reboot, it gives me an $0000000B Guru and goes into an indefinite
: >reboot. However, if I keep the case of, it runs fine. Sounds like a
: >heat problem, right? But how do I fix it? The power supply fan seems
: >to be working, and the new drive isn't running hot. This problem never
: >happened in the 4 odd years I've had this computer...

Well, sounds to me like your A2000's power supply isn't 100% pumping out
the voltage spike required on startup.  (Chances are the 5vdc is less than
5vdc on power up, which means, the new HD is stealing too much to spin up,
which is causing the CPU to get what's called a "mixed" signal voltage,
which causes all the i/o lines on the CPU to flip/flop depending on the
voltage change, which would cause such a crash.  This is typically a
problem with the capacitors inside the power supply.  One way to help
avoid this, is to turn up the 5vdc voltage to typically about 5.25vdc.
Use a voltmeter plugged into one of the HD power connectors inside the
machine, off the supply, and turn on the machine.  It should spike at
about 5vdc, anything less and you'll run into troubles.  If indeed it is a
heat problem, chancse are the capacitor that regulates the voltage is
failing due to that heat.  Since those supplies should run fine fanless
and in 90F temperatures for a few years non-stop.

Alex...

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ron

In order to keep my 2000 cool, I got a higher-volume muffin fan from
a used computer show that runs right of 110V AC, and basically duct-taped
it over the existing power supply fan (ensuring that both fans pull air
in the same direction).  I also removed the slot covers from the
IBM slots to allow extra air into the machine.  I can stick small bits of
paper to the air intake slots on the front now, and I am going to make
some cardboard dust covers for the floppies since there is a huge volume
of air moving through the machine now (which is good because I have every
slot EXCEPT the IBM slots filled, so airflow is my friend).

My 3000 has been given the same treatment, without much success.  I
even cut a hole in the side of the machine where the expansion slots
are and mounted a filtered, inward blowing fan there in an attempt to
moderate the heat on that side of the machine (if you touch the bottom
of the 3000 roughly underneath where the CHIP ram is, it is VERY hot
even with the extra blowers).  I'm open to suggestions on how to get that
extra heat under control...

--
...cruising down the Information Superhighway at 14,400 BPS...
          ....without a license!          Wolfram Gottfried

  (when replying, take out the "!")       Team AMIGA

|  Ok, this is weird: I installed a new hard drive, and now my Amiga
|  4000/040 runs perfectly for about 15 minutes, then it freezes up. When
|  I reboot, it gives me an $0000000B Guru and goes into an indefinite
|  reboot. However, if I keep the case of, it runs fine. Sounds like a
|  heat problem, right? But how do I fix it? The power supply fan seems
|  to be working, and the new drive isn't running hot. This problem never
|  happened in the 4 odd years I've had this computer...
|
|  Any help would be *greatly* appreciated....

I had a similar problem with my A4000 until I moved my SCSI drive to an
external case.  The problem usually isn't individual components running
hot, but air flow.  A CPU fan may help, but make sure the space over the
CPU is free of obstructions.

--
remove the spoiler to send me email
Tom Hayko                       Team AMIGA

First of all, thanks to all who responded! Unfortunately, it seems
that there is something more seriously wrong with my Amiga 4000, and
the heat was only causing it to become apparent. For the last couple of
days, it won't boot up at all any more, case on or off! :( The drive
spins, the fan's running. but I just get a black screen. Once in a
while I'll get a Guru error, but sometimes I get nothing. If I
disconnect the hard drive I get the same result. Any suggestions? Any
recommendations for places to get Amigas repaired?... :|

   Marc Atkin            //
U of Massachusetts      //                " Goosnargh. "
   at Amherst       \\ //

 TH>|  Ok, this is weird: I installed a new hard drive, and now my Amiga
 TH>|  4000/040 runs perfectly for about 15 minutes, then it freezes up. When
 TH>|  I reboot, it gives me an $0000000B Guru and goes into an indefinite
 TH>|  reboot. However, if I keep the case of, it runs fine. Sounds like a
 TH>|  heat problem, right? But how do I fix it? The power supply fan seems to
 TH>|  be working, and the new drive isn't running hot. This problem never
 TH>|  happened in the 4 odd years I've had this computer...

 TH> I had a similar problem with my A4000 until I moved my SCSI drive to an
 TH> external case.  The problem usually isn't individual components running
 TH> hot, but air flow.  A CPU fan may help, but make sure the space over the
 TH> CPU is free of obstructions.

Another solution would be to check if the fan is really blowing the air out
of the case and not into it. Some A4000 had this assembling-error, which
can be resolved by changing the plus and the minus...

Bye, Markus

<tsb>
<sb> Markus Weissbecker AKA Maui
<sb> F-69007 Lyon

<sb> Tatoo: 06 57 15 25 73
<tsb>

WIN95 -> We Invented Nothing 95

Quote:>Another solution would be to check if the fan is really blowing the air out
>of the case and not into it. Some A4000 had this assembling-error, which
>can be resolved by changing the plus and the minus...

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                             mrivers *(at)* gte.net

These addresses are not mine, but from companies who persist at spamming.
   They are here for targeting by other spammers who scan newsgroups.

Quote:> Another solution would be to check if the fan is really blowing the air out
> of the case and not into it. Some A4000 had this assembling-error, which
> can be resolved by changing the plus and the minus...

Regards,
David Myers,
NWAUG Secretary

--
regards,
greg
------------------------------------------------------------------------------
Greg L. Kimnach
NASA Lewis Research Center
Power Technology Division
216-433-6251
I opted for Betamax, the world for VHS. I for Amiga, the world for IBM
clones.
"Do or do not.  There is no try!"  --Yoda.
------------------------------------------------------------------------------

Hi,

Quote:>>Another solution would be to check if the fan is really blowing the air out
>>of the case and not into it. Some A4000 had this assembling-error, which
>>can be resolved by changing the plus and the minus...
>You should turn the fan around if it's backwards, running the fan backwards
>(power is reversed) is not as efficeint as the fan blades are designed to
>spin a certain direction.

1. Old fans from PSU are AC 110-220V, to reverse them you need either to
replace fan-blades or rewire motor. So reverse is almoust imposible.
2. New DC fans are bruscher wich special circuit for DC->AC circuit.

Simply you can turn fan upside down and you'll get reversed cooling. BUT
remember sucking is not good. You need to direct air flow with some guides
made of plastic or paper. Better blow air to most heating place. In my A1200 I
placed CPU cooler fan to blow air between 2" HD and mother board. (Overheating
of graphics chips = garbage on screen) NOw HD and GFX chips are cold.

Bye, Levas
--
<tsb>Amiga? Amiga... Amiga!

A Shower is the halfway point between Bed and World.

Quote:>Hi,
>>>Another solution would be to check if the fan is really blowing the air out
>>>of the case and not into it. Some A4000 had this assembling-error, which
>>>can be resolved by changing the plus and the minus...
>>You should turn the fan around if it's backwards, running the fan backwards
>>(power is reversed) is not as efficeint as the fan blades are designed to
>>spin a certain direction.
>Don't speak bullshit!
>1. Old fans from PSU are AC 110-220V, to reverse them you need either to
>replace fan-blades or rewire motor. So reverse is almoust imposible.
>2. New DC fans are bruscher wich special circuit for DC->AC circuit.

I didn't suggest that one should reverse polarity on the fan,
I said that "it is inefficient to run the blades backwards".
Whether or not you can actually run the fan backwards was not my
point.  So please don't take that tone of text with me.

Quote:>Simply you can turn fan upside down and you'll get reversed cooling. BUT
>remember sucking is not good. You need to direct air flow with some guides

--
                             mrivers *(at)* gte.net

These addresses are not mine, but from companies who persist at spamming.
   They are here for targeting by other spammers who scan newsgroups.