#Strange Hardware Problem
31 messages in this thread
Don,
On another topic, perhaps you can help me with a different problem.
In the past two weeks I've experience an interment problem. On boot the
Amiga screen turns a yellowish color (with greenish tint) and the power LED
blinks on and off. The machine will hang in this state for awhile, then
attempt to reboot, but continuously falls into the original state. The
probem seems to eventually disappear by completing shutting off the power
for a few minutes and then starting up again. This is intermitent in that
it's only happened three times. The first two times I ended up spending
hours taking everything out of the machine and trying to boot. This
worked. But when I would reinstall any board it would fail to boot.
Almost as though there was no power on the expansion bus or some kind of
low voltage short. Any ideas?
Steve,
Yellow color…I forget the meanings of the colors, I'll try to
find it, I've got them somewhere around here…but my memory says that
yellow indicates a problem with the system ROM. But it could be one of the
other things like chip RAM or the CPU.
So I'd suggest you attempt to reseat all the socketted chips on the
motherboard and see if that helps. Putting boards in/out of the Amiga can,
in certain cases, cause a bit of a twist to the motherboard causing chip to
socket contact to become flakey.
Don
I believe there is a text file in AmigaUser that gives the colors that
indicate start-up errors. I know that I wrote one for Transactor, and I
think I put all of my Transactor stuff up here.
BOOTCO.LHA/Bin Bytes: 2862, Count: 60, 20-Aug-92
Title : TRANSACTOR article describing boot colors, etc.
Keywords: BOOT COLORS ERRORS TRANSACTOR CLAY
This is an article I wrote for TRANSACTOR magazine in 1987. It
describes the startup routines in the Amiga and the tests made upon
bootup. It gives the screen colors that indicate the progress as it
boots – both normal boots and those that show errors. The flashing of
the caps light on the keyboard are also explained. Author:Betty Clay
This is in Library 12 of AmigaUser.
—Betty
Betty,
Interesting…I did a search on keyword BOOT last night…it didn't
come up…but it's certainly there now. And I've now got a copy in
someplace I'll remember <grin>.
thanks!
Don
I knew that I put my name in the keywords of each of the articles I wrote,
so I searched with the keyword CLAY. Perhaps I should change those
keywords and put BOOT in there, since that was the logical key for you.
—Betty
Betty,
BOOT is in the keywords…that's what's weird. I just checked
again, from the LIB promp, it's found with a bro /key:boot /lib:all, but if
I go to the Amiga File Finder, it's not found either by keywords or
filename!
I wonder why the file finder can't find it? It's certainly been
there long enough.
Don
No idea, Don. I don't use the file finder much, since I can usually
remember which forum something would be in.
—Betty
Betty,
I don't use it much either, and I *think* I also did the keyword
search both here and in tech…but now don't remember. Oh well.
Don
Don,
Thanks for the ideas. This is a strange problem which now seems to
be reoccuring with greater frequency, yet eventually I have been able to
get the system to boot, so it's difficult to determine what might cause the
problem. At least if I can narrow things down to something manageable I
might be able to fix it.
Steve,
Ok…well, Betty pointed me to her file that described the bootup
sequence and included the meaning of the colors. It's in LIB 12 as
BOOTCO.LHA and I'd suggest you go get it (it's a very quick download, only
2K long) and read it, it'll explain it much better than I can here in the
message base.
Basically…if the screen is truely yellow, it's saying that the
68000 found an error before the error trapping mechanism (GURU) was in
place. In other words…bad boot code, or flakey RAM where the boot code
is loaded.
Don
Don,
Well, does the boot code load into chip ram? That's the only ram
on the motherboard. I haven't had any previous problems with the 2.04 ROM
and usually ROMs don't just die or go semi, do they? The system seemed to
work the first time this showed up only after I removed all the expansion
boards, which included the two which have fast ram on them. I did install
the 2 meg chip upgrade from DKB. Maybe the one jumper lead which uses that
little syringe like clip-on might be loose. I have noted that if I sht the
machine off for a long time, like 24 hours, the problem recurs, but if it's
shut down for only a few hours it will work fine. In the former case it
seems that if I keep doing a warm boot over and over, it eventually boots
up.
Steve,
I forget all the details, so some of this is probably wrong…but
in essense, the ROM is "moved" to low memory during bootup, and then later
"moved" back to high memory. When it's moved back, among other
things…address 4 is setup to point to a list of routines. This is in
CHIP memory and if those offsets are wrong…as it references them during
startup…things could easily go into weird mode.
I'll look and see if I've still got my reference to the above
around here somewhere and try to get you the exact details if you wish.
Don
Don,
Then, if what you say is correct, I can probaby assume that my
problem is arising while the boot code is in chip ram. That might point a
finger at the MegaChip. A single lead is clipped onto Denise or Gary, I
forget which, but if the contact is not good, perhaps that is my problem,
or it may be with the MegaChip itself. Perhaps, I need to do a little work
in the machine and be sure that clip lead is securely connected or
alternatively see if I can carefully solder the lead to eliminate any
chance of poor contact.
STeve,
That sounds reasonable…I'd check first with Dean though, see what
he says.
Don
Don,
Well, I did get into the box this morning and checked the board
seatings, cleaned contacts, and checked the Megachip clip lead to be sure
it was secure. I couldn't identify anything that looked out of the
ordinary. I'm beginning to wonder if something is suffering a slight heat
(or cold) related problem and that once the machine is turned on cold it
takes a moment for it to warm up, but too late for the boot sequence. Then
after a few moments (or whatever time it takes for consecutive warm boots)
it finally wakes up. If that's the case it's a bear of a nut to crack,
especially if it's not a chip but a circuit component like a resistor or
cap. I'd hate to think that the motherboard is going flakey on me.
Steve,
Obviously, it'd be good if you could get it to do this all the
time, then it'd be easy…remove one thing at a time and see if it goes
away. But yes, since it's intermittent, and you're sure everything is
seated correctly…it'll be tough to track down.
Don
Don,
At Dean Brown's suggestion I ran mbrt on the system just to see if
any memory faults showed up, but after running several iterations of the
four available tests nothing showed up. Of course this only took about 20
minutes or so to do, so if the problem is so rare as to show up only
sporadically once the machine has gotten past the cold boot, 20 minutes is
probably not nearly long enough. Given that the problem only seems to
manifest itself at the time it's turned on for the first time that day, and
that in a short time it will warm boot normally and run apparently normally
from that point on without the problem ever materializing again (at least
in any obvious way) makes this a truly bizarre problem to identify. I
think the only way it would likely be detected is when it seems alwasy to
occur — at the cold boot time. And because that won't always produce the
problem unless the machine has been shut down for awhile, even that becomes
a trial. But at least at that moment someone with the test equipment
suited for the job might ultimately be able to identify the source. I do,
however, really appreciate the fact that several of those here on CIS were
kind enough to offer suggestions and helpful hints.
Steven,
Get a good memory test program and test all of your CHIP ram. (MRBT2
over in AmigaVendor is a good test program) If you find a problem, call
our tech support line and request an RA number to return the MegAChip.
We'll check it out for you. I rather doubt the clip is loose as that
usually causes the machine to never boot correctly. Also you can describe
your system configuration and I'll try to track down what the problem
might be.
Dean
DKB Software
Dean,
Thank you for that suggestion. I will check the memory and see if
anything shows up. Although what is truly strange is that once the system
does boot it works fine and withough failure. Only seems to be this
strange occurance on the cold boot after the machine has been off for quite
a while. I did check the clip lead and it was secure. But I will run a
memory check.
Steven,
If you can't identify the problem, and wish to determine if the
MegAChip is at fault call and make arrangements to send the MegAChip back
and we'll test it out for you.
Have you ever been able to configure your machine in a way that the
problem doesn't show up? It would help alot if we could narrow down the
possible areas of problems.
Dean
DKB Software
Dean,
When this problem first occured the only way I was able to get the
machine to boot at all was to remove ALL of the expansion cards and boot
with just the bare machine and chip ram. That worked OK, but then when I
installed any one board the boot failure occured. I shut the machine down
and came back to it the next day and was finally able to reinstall all the
cards and it worked fine. Then the next day when I turned it on it
wouldn't boot. I shut it off and turned it back on, then warm booted
several times until finally it came up. Since then it seems that if the
machine is off for at least 24 hours it won't boot up until it's been on
for a few moments and I go through a series of warm boots or let it fail
and reboot on its own until it comes up. However, today, after having been
on for several hours, it started failing in midstream. I would warm boot
OK, but then after several minutes or more it might fail. After shutting
it off for an hour or so, it came back to life. I then shut it down,
removed several cards and cleaned contacts, checked the GVP accelerator
card's xtal, reinstalled everything and it's working OK right now. Given
that it once only would boot up with chip ram installed, I doubt the
problem is Megachip. I also ran mbrt several times and found no faults. I
have quite a few cards installed. A GVP 3001, AmaxII Plus, Nexus
controller/ memory, A2386 BB, VGA memory card, PC SCSI controller, and PC
I/O card. I do note that when it fails to boot, the hard drive is never
accessed. The power LED starts blinking (as it does on all failures I've
had), the screen will blink and on occassion I will get a GURU software
failure alert.
Steven,
Have you ever checked the power supply voltages with a fully loaded
machine. It's possible that your power supply may be going south. Other
than that, I can't see anything that would cause your problems with the
configuration you have.
Dean
DKB Software
Dean,
I considered that possibility, but haven't put a VOM on the lines
to see how the voltages are. Suddenly it's back to working normally again,
at least the past day. I don't know how much power the mother board
consumes, but I figured that all the cards in the system for which I have
power draw info wouldn't consume more than 100 watts, and the supply is
supposed to handle 200, I think.
Yea….good ideas over here…..I was having problems like that awhile ago
with my A3000. The cause of it was corupt WB software. Try booting off of a
floppy and see if you get the problem. If so reinstall your system
software. If that doesn't do it it sounds like you have a flakey expansion
card.
Dave
Elite MicroComputers 908-541-4214 – via Whap!
Dave,
OK, I'll give that a try. However, if memory serves me correctly I
don't think the machine would even boot off floppy because the failure
occured before the boot sequence ever began, but I'll try that the next
time it happens just to be sure. I don't know if it's a flakey expansion
board or system board since the first time it happened I took out all the
boards and then tried putting different ones in at a time. It seemed to
make no difference what card went in, though. Don Curtis suggested it
could be something flakey on the motherboard itself, perhaps need to reseat
socketed chips, etc.
If it is a chip it is most likley the super buster.
Dave
Elite MicroComputers 908-541-4214 – via Whap!
Dave,
I have a 2000, I don't think I have that chip, do I?
No you don't…..I thought you where talking about an A3000.
Dave
Elite MicroComputers 908-541-4214 – via Whap!
Steve,
Do you have an A3000? Were you running PKaZip? I have had the same
problem but only when running PKazip. It crashes and then I get the dang
green screen that keeps coming back with each reboot attempt. Truning off
the machine for a few seconds fixed the problem for me.
Mark,
No, I have a 2000 and this problem just cropped up when first
booting. I need to turn the machine off for awhile, or try warm booting a
few times or a combination of both, then eventually it comes alive.
Green screen indicates a memory problem….yellow is a bus (expansion card)
problem.
Dave
Elite MicroComputers 908-541-4214 – via Whap!