Amiga 3000 screen prob.
20 messages in this thread
Can anyone help me?
I am responsible for looking after 40 or so A3000's used by my employer for a
graphics application. I currently have two 3000's which have the same problem,
as follows:
The top edge of the screen display (on a vga monitor connected to the 15 pin
high density d connector) flickers randomly with a blue tinge. If I open a
window, for example system2.0, and then resize the window by dragging on the
size handle, random pixels are illuminated on the workbench screen within this
window. They can be cleared by executing a 'redraw all' command, but will
reappear when the window is resized.
I have a known good A3000 and I have substituted all the pluggable i.c's
related to the screen one by one to no avail.
I am starting to get very frustrated by these machines and the users are
wanting them back !
As I am more used to (ho hum..) pc compatibles, I am now stuck.
Has anyone out there seen (and beaten) this problem before?
Is there an engineer who could restore a fellow engineers' sanity ?
Hope so…
And lastly..
Does anyone know what the maximum size (Mbytes) scsi hard drive can be fitted
to an A3000 ?
Robin.
I seem to remember some time ago reading some messages on the Internet
about the 3000's random pixel problems. If I remember correctly, the
solution was to upgrade or replace one of the PAL's. But it's been quite
some time since those messages were posted so they are probably long gone
by now. Hopefully, someone on here might have captured the messages or
knows of the solution.
// John – (TechnoJunkie at heart)
\X/ Mercury@ins.infonet.net
Hi John, thanks very much for the reply.
There is definitely something in what you say because i've found that cooling
one of the p.a.l chips ( I forget which one..) with aerosol freezer stops the
problem for a few minutes until it heats up again. I've tried a new chip
however, and this doesn't cure the problem. I'm wondering if the chip i'm using
is not the updated version, assuming one exists.
I might well try leaving a message on the CBM forum just in case one of their
guys knows any more about the problem, that is if there is still anyone there
given their recent problems.
Once again, cheers.
Robin.
Hmmm….it does sound like a heat problem with some of the chips in the
3000. Is there enough room to install a extra fan above the PAL? Or you
might be able to mount one of those small CPU fans that will let the PAL
keep its cool.
// John – (TechnoJunkie at heart)
\X/ Mercury@ins.infonet.net
Hi again John,
Yep I have seriously considered cheating to solve this problem. I've spent some
more time trying to resolve the fault without any success.
I posted a message on the commodore service forum but nobody has come back to
me – is there still anybody there I wonder, given Commodore's recent dilemna.
I'll try lashing a small fan in and perhaps a clip or bond on d.i.l heatsink
clip.
Watch this space……
CU
Robin.
Robin: I don't think anyone is going to reply to your message in the
Commodore service forum. Even when CBM was going pretty good, it was rare
that anyone showed up from CBM to answer questions, and then he would get
on here once every 2 weeks or so. Now that CBM is a non-entity in the
states, your chances are pretty darn slim <g>. Maybe the heatsink will do
some good, sure couldn't hurt any. If that doesn't work, maybe a small
refrigeration unit inside would. If nothing else, you could put your
bottles of brew on top to keep them icy <g>.
// John – (TechnoJunkie at heart)
\X/ Mercury@ins.infonet.net
Hi John,
I was coming to the same conclusions myself, it sure does seem pretty silent on
the CBM service forum. I suppose I should have expected this:
a) Because of CBM's recent problems.
b) When i've contacted CBM U.K to get technical advice they've been less use
than a chocolate teapot <gr>
It's no surprise is it really that they've got into their present situation
given that they seem to have marketed their hardware on a 'shareware' basis
(user supported <gr>).
I've now a problem getting hard drives for these machines because no-one sells
Quantum LPS105S drives anymore now that MS Windows guzzles hard disk space like
it's going out of fashion. It seems that I have to buy 340Mb drives now. That's
assuming that they will be o.k- the A3000 has a S.C.S.I interface on board as
you no doubt know but i'm not sure if there is any restriction on size- any
ideas ?
Cheers
Robin.
Robin,
My 3000 SCSI has been _wonderful_ everything except a scanner that I've
plugged in has worked (well an Apple SCSI CD-ROM didn't either). Last
weekend I installed a 1.6gig HD … no problems., just plug, format, play.
Well I don't think there are many restrictions on hard drive size for the
3000, so go ahead and buy that 2 Gigabyte drive <g>. Actually, we should
be happy that Windows and most of it's applications are HD Hog's. Us Amiga
owners are getting large hard drives for very reasonable prices. So the
more hogish their applications are, the better for us <g>.
// John – (TechnoJunkie at heart)
\X/ Mercury@ins.infonet.net
Hi John,
I've had a sudden rush of replies about my A3000 problems, a guy in Germany
came back to me with some info. which points to the PAL chips being suspect in
some older A3000 motherboards, as you suggested, so I have ordered some of
these from my supplier here in the U.K- problem is that they don't have any in
stock and will have to order them from Germany…..
Oh well c'est la vie <g>
Another guy from Holland <I think> agrees that there is no size limit on the
scsi interface used in the A3000 so i'm going to have to go for the 170Mb
drives now I think. Seems silly really as these units are only used for one
task and they just sit there 24 hours a day being sent data down their serial
ports to tell them which maps to display – the users don't even have a keyboard
connected. The software on the hard drives only needs 75Mb approx and once
loaded thats it, no changes <until the next time it goes wrong again><gr>
I'll probably be drawing my pension by the time I get the bits and finally get
these beasties sorted…….
It's been good talking to you, thanks for your help,and i'll let you know how I
get on.
Regards
Robin
Well it just shows you how much has changed in the last few years. When I
purchased my first hard drive just after the A500's came out, it cost me
around $625 and was only 20MB. Now you can buy a 1 Gig drive for about
that much, and as you know, it's hard to find anything less than 170MB.
Myself, I'm waiting for those holographic memory cubes to come out 8^)
// John – (TechnoJunkie at heart)
\X/ Mercury@ins.infonet.net
Hi John,
Yep, there's no doubt about it, now is the time to get a hard drive. Just wish
that the same could be said about simm modules. When I built my pc up from bits
I paid L15/simm but since the fire in wherever it was last year you can't get a
1Meg simm for less than L28 ! Seems to me like that fire was just a great
excuse for somebody to get rich real quick. Maybe i'm just jealous 'cos it
wasn't me <gr>. I have 4Mb in this pc and it badly needs another four to run
Borland Paradox for Windoze. I had to get some memory zip chips for one of the
A3000's some time ago and they were a silly price too.
I've contacted my supplier to get those PAL chips, and guess what, they're out
of stock and will have to be ordered from Germany. A guy called Wolf Faust
(100116,1070) came back to me and said that he'd had some on order in Germany
for months without success, so i'm not going to hold my breath!
ttfn
Robin.
Robin,
1. I assume you have done this, but are you sure the flicker fixer is
adjusted right? You'll find a small hole at the back of the A3000. Using a
plastic screwdriver (at least on my two A3000 a plastic screwdriver was
shiped with the computers) you adjust the flicker fixer until the flicker
stops.
2. In case it's not the flicker fixer, you might check out the PAL chips
on your motherboard. To tell you the whole story:
One of my A3000 suddenly had problems. "Noise", similar to the one you
describe, appeared on the screen. After several weeks, the floppy drive
doesn't seem to write reliable when using the CPU heavily. Also, the noise
was increased with the amount of CPI workload.
The A3000 was pretty old and after exchanging the PAL's at location U203
(Sticker No. 390527-02 and U202 (Sticker No 390526-02) everything was
fine. Funny about it: I got the two PALs from the newer A3000 I bought.
After exchanging the PALs both Amigas now run fine (yes, I checked
again… it really was the PALs causing the problems). So it seems that
some PAL's do have problems with older A3000 boards.
I heard of two similar cases lately! (PS: try switching chips at U203,
U202, U701, U714 with your second A3000. Might turn out that something has
changed 😉
— Wolf Faust, Am Dorfgarten 10, 60435 Frankfurt, Germany —
Hello Wolf,
Thanks for the reply, I had suspected U202 as the problem cleared for a short
while if I sprayed the I.C with aerosol freezer. I've got the P.A.L's on order
now but it seems that they are presently unavailable from CBM United Kingdom
and will have to be shipped in from Germany.
I suppose that this is due to the problems that CBM U.S are having.
Fingers crossed…….supplier can't give me any idea as to how long this will
take.
Regards,
Robin
Yes, I ordered the PAL several months ago. But I simply can't get hold of
them… that's why I keep the second A3000 as "spare part".
AND
There is a limit to the HD size on the A3000 SCSI bus like any other FFS
device. As far as I can remember the size limit was 2,147,483,647 (that's
an LONG used by the FFS) per partitions. So when buying a 5Gig HD and
formating with one partition, you will most lake face some problems. The
problem might not show up immeaditly…
— Wolf Faust, Am Dorfgarten 10, 60435 Frankfurt, Germany —
But didn't the limit get fixed by the time 3.1 was released? (stupid
signed arithmetic…)
Dale L. Larson Intangible Assets Manufacturing (info@iam.com)
"That's the best part about being crazy. You see things no one else can see."
No, the FFS limit is there… as far as I know they fixed some bugs and it may
now work up to 4.xGig… but no promises…
s
Hello Wolf,
I thought that there might be problems in getting these spares, as I have had
problems getting the CIA chips (the ones that drive the serial ports amongst
other things..) even whilst CBM was operating normally (should I say
<relatively> normally ?)
I suppose that i'll be drawing my pension by the time they arrive <g>
The hard drive size limit won't be a problem, it's just that I have two units
with faulty 105Mb drives and I can't get anything smaller than 270Mb. Same
price as the old drives so I can't complain but a waste really as these
machines are only used for one purpose (mapping and location etc.) which only
requires some 90Mb. I was just a little nervous about buying bigger drives
until I was sure that they would be o.k….. the boss wouldn't see the funny
side of two drives that we couldn't use <g>
Thanks for your help Wolf, i've only been on CIS for about two weeks and
already it has been of great help thanks to people like yourself.
Regards,
Robin.
Robin,
About your SCSI in a 3000 question. There is room for any size SCSI
drive inside the cabinet of a A3000. Either two 3.5's or one 5 1/4 drive
can be fit with no extra hardware. Except for a extra SCSI drive
connector for a second drive.
In other words, if you can find a 10 Gig 5 1/4 SCSI compliant drive you
can use it… SCSI doesn't have a capacity limit.
//
Gary Vander Mei on Auto-Pilot \X/
Hello Gary,
Thanks very much for the information, I'll feel happier about spending my
bosses' money knowing that the drives will work <g>
Cheers,
Robin