I've got a Powermac G4 (Mirrored Drive Doors) and the memory
specifications are as follows:

256MB or 512MB of PC2100 or PC2700 DDR SDRAM

Four DIMM slots support up to 2GB of SDRAM

I currently have 768 MB installed and ordered three 512 MB modules from
an eBay auction (seller has 100% FB).

I removed the 256MB module and installed the 3 additional 512 modules
and the computer won't start. Tried several times to no avail and I'm
not a novice at installing memory.

So, I removed them and am back to my 768MB

The auction copy states:

512MB DDR*PC2700 333 Mhz

SPECS:
Size: 512MB
Speed: 333Mhz
Pin Count: 184PIN
Type: DDR Memory
ECC: No

The modules which arrived read: VM512MB DDR PC333

If anyone can clue me in as to what could be the problem, or if I've
managed to order the wrong memory, please help!

Thanks so much,
Michelle

M wrote:
>
> I removed the 256MB module and installed the 3 additional 512 modules
> and the computer won't start. Tried several times to no avail and I'm
> not a novice at installing memory.
>

Try installing just one of the new modules. If the computer won't boot
try a different one. The reason for this is that the two most likely
scenarios are: (a) the memory is not compatibile with you machine or (b)
perhaps just one of the three new modules is bad.

Good luck,

Paul

Remember when you install memory RAM that you can't just put them in there
in sequential order. You have to start out and work your way in. Go online
or look at your computer manual to find out what order your RAM should be
installed, but basically it's like this. Say you have 6 slots. You would
probably put your RAM in 1, then 6, then 2, then 5, then 3, then 4. If you
put your RAM in 1, 2, 3, 4, 5, 6 your computer can't address the RAM as
available.

The other way is put the RAM in one at a time till they are all in the
computer and the computer recognizes all of it.


Kind Regards,
Nathaniel
--
flikWORLD Design
reply to: nat at flikworld(dot)com



in article surf2me-770F99.17153012122003@news06.west.earthlink.net, M at
surf2me@NOSPAMearthlink.net wrote on 12/12/03 5:15 PM:

> I've got a Powermac G4 (Mirrored Drive Doors) and the memory
> specifications are as follows:
>
> 256MB or 512MB of PC2100 or PC2700 DDR SDRAM
>
> Four DIMM slots support up to 2GB of SDRAM
>
> I currently have 768 MB installed and ordered three 512 MB modules from
> an eBay auction (seller has 100% FB).
>
> I removed the 256MB module and installed the 3 additional 512 modules
> and the computer won't start. Tried several times to no avail and I'm
> not a novice at installing memory.
>
> So, I removed them and am back to my 768MB
>
> The auction copy states:
>
> 512MB DDR*PC2700 333 Mhz
>
> SPECS:
> Size: 512MB
> Speed: 333Mhz
> Pin Count: 184PIN
> Type: DDR Memory
> ECC: No
>
> The modules which arrived read: VM512MB DDR PC333
>
> If anyone can clue me in as to what could be the problem, or if I've
> managed to order the wrong memory, please help!
>
> Thanks so much,
> Michelle

Mix 'n match them with your existing RAM modules until you find what
combination doesn't work. That module is the bad one. Or, if none of them
work:

a) that memory is incompatible with your computer, or
b) they're all defective.

Good luck,
--
DaveC
me@privacy.net
This is an invalid return address
Please reply in the news group

Nathaniel Flick <nat@flikworld.com> wrote:

> Remember when you install memory RAM that you can't just put them in there
> in sequential order. You have to start out and work your way in. Go online
> or look at your computer manual to find out what order your RAM should be
> installed, but basically it's like this. Say you have 6 slots. You would
> probably put your RAM in 1, then 6, then 2, then 5, then 3, then 4. If you
> put your RAM in 1, 2, 3, 4, 5, 6 your computer can't address the RAM as
> available.

Where did you come up with this? I don't know of _any_ Mac that's ever
exhibited this behavior. Over the years, there have been models that
required banks of 4 matching SIMMs be installed at once, and there have
been others that required matching pairs of SIMMs or DIMMs, but there
have never been any as you've described.

The MDD G4 the OP owns has 4 DIMM slots, which can be filled with any
combination of 128, 256 or 512, in any order.

--
Mike Rosenberg

<http://www.macconsult.com> Macintosh consulting services for NE Florida
<http://bogart-tribute.net> Tribute to Humphrey Bogart

Mike Rosenberg <mike@POSTTOGROUP.invalid> wrote:

> Where did you come up with this? I don't know of _any_ Mac that's ever
> exhibited this behavior. Over the years, there have been models that
> required banks of 4 matching SIMMs be installed at once, and there have
> been others that required matching pairs of SIMMs or DIMMs, but there
> have never been any as you've described.

It occurs to me you may be thinking of the models in which installing
matched pairs in the appropriate slots would allow for memory
interleaving, which could give you a modest speed boost. That, however,
was strictly optional.

--
Mike Rosenberg

<http://www.macconsult.com> Macintosh consulting services for NE Florida
<http://bogart-tribute.net> Tribute to Humphrey Bogart

On Mon, 15 Dec 2003 16:20:31 GMT,
Nathaniel Flick (nat@flikworld.com) wrote:
> Remember when you install memory RAM that you can't just put them in there
> in sequential order. You have to start out and work your way in. Go online
> or look at your computer manual to find out what order your RAM should be
> installed, but basically it's like this. Say you have 6 slots. You would
> probably put your RAM in 1, then 6, then 2, then 5, then 3, then 4. If you
> put your RAM in 1, 2, 3, 4, 5, 6 your computer can't address the RAM as
> available.

No offense intended, but you don't know what you're talking about. There
have been Macs in which SIMMs had to be installed in pairs (and it weren't
no slot 1 & slot 6 pairs), but these were long ago. The G4 that the OP
doesn't have any such restriction.
--
Bev A. Kupf
"The lyfe so short, the craft so long to lerne" -- Chaucer

In article <1g61xnn.1ucspfa1xqak08N%mike@POSTTOGROUP.invalid> ,
mike@POSTTOGROUP.invalid (Mike Rosenberg) wrote:

> Mike Rosenberg <mike@POSTTOGROUP.invalid> wrote:
>
> > Where did you come up with this? I don't know of _any_ Mac that's ever
> > exhibited this behavior. Over the years, there have been models that
> > required banks of 4 matching SIMMs be installed at once, and there have
> > been others that required matching pairs of SIMMs or DIMMs, but there
> > have never been any as you've described.
>
> It occurs to me you may be thinking of the models in which installing
> matched pairs in the appropriate slots would allow for memory
> interleaving, which could give you a modest speed boost. That, however,
> was strictly optional.

I'll have to check when I'm at work, but I think the G5s require pairing
of memory. There's a diagram in the booklet involving 8 slots and
showing how to add two memory cards, but I don't remember the details.

--
AF
"Non Sequitur U has a really, really lousy debate team."
--artyw raises the bar on rec.sport.baseball

I think all Mac computers require this pairing of memory, all the way back
to my old 7200/90MHz Power Mac. You have to alternate from the outside in,
in many cases but not always. For example, for slots 1-6 you might insert
your ram 1,6,2,5,3,4. But pay attention to your particular computer's RAM
Diagram for more exact documentation.


Kind Regards,
Nathaniel
--
flikWORLD Design
reply to: nat at flikworld(dot)com


in article afaber-E64610.08580816122003@reader2.panix.com, Alice Faber at
afaber@panix.com wrote on 12/16/03 5:58 AM:

> In article <1g61xnn.1ucspfa1xqak08N%mike@POSTTOGROUP.invalid> ,
> mike@POSTTOGROUP.invalid (Mike Rosenberg) wrote:
>
>> Mike Rosenberg <mike@POSTTOGROUP.invalid> wrote:
>>
>>> Where did you come up with this? I don't know of _any_ Mac that's ever
>>> exhibited this behavior. Over the years, there have been models that
>>> required banks of 4 matching SIMMs be installed at once, and there have
>>> been others that required matching pairs of SIMMs or DIMMs, but there
>>> have never been any as you've described.
>>
>> It occurs to me you may be thinking of the models in which installing
>> matched pairs in the appropriate slots would allow for memory
>> interleaving, which could give you a modest speed boost. That, however,
>> was strictly optional.
>
> I'll have to check when I'm at work, but I think the G5s require pairing
> of memory. There's a diagram in the booklet involving 8 slots and
> showing how to add two memory cards, but I don't remember the details.
>
> --
> AF
> "Non Sequitur U has a really, really lousy debate team."
> --artyw raises the bar on rec.sport.baseball

Nathaniel Flick <nat@flikworld.com> wrote:

> I think all Mac computers require this pairing of memory, all the way back
> to my old 7200/90MHz Power Mac. You have to alternate from the outside in,
> in many cases but not always. For example, for slots 1-6 you might insert
> your ram 1,6,2,5,3,4. But pay attention to your particular computer's RAM
> Diagram for more exact documentation.

Um, did you read my previous posts in this thread? You certainly had
the opportunity to, since you quoted them, but did you actually _read_
them? What you're saying was not true on the 15th when you first posted
and it's still not true today. There have been Macs that required RAM
be installed in matched pairs, going all the way back at least to the
SE, and also including the Power Mac x100 series. Some Macs, such as
(but not limited to) the SE/30, IIcx and IIci, required matched sets of
four SIMMs. However, even the 7200 you mentioned, all of the other PCI
Power Macs in that series, and all of the G3s and G4s take RAM one DIMM
at a time, and it doesn't matter which slot is filled when. The G5s
require matched pairs, but the order in which the slots are filled
doesn't matter.

As I mentioned, some Macs that don't require matched pairs will gain the
small speed benefit from memory interleaving if you do install in pairs,
but that does NOT include the 7200.

--
Mike Rosenberg

<http://www.macconsult.com> Macintosh consulting services for NE Florida
<http://bogart-tribute.net> Tribute to Humphrey Bogart