128 Mb module not working in Blizzard PPC. Where is the problem ???

[Effy]

So far I have sold at least 20 identical 128 Mb memory modules. The first ones are still working in my own Blizzard PPC 240/060 but to avoid damaging while testing all the other modules, I have now used an old 80486 to test the modules. If the memory holder breaks off then it´s no drama, but if the same thing happens to my Blizzard PPC then it would kill me.
So, every module I sold is tested in the 80486. A single module is inserted and computer is turned on, memory is being checked in Bios and Windows is being loaded. So far none of my modules has failed. But I did get two bad reports from two buyers :

-Buyer 1) both modules work 100% if inserted seperately but when used together then only one will be "seen" ...  :-o

-Buyer 2) one module is not working, computer runs slow, as the buyer said "I've tested both simms in isolation and this one simm causes either the machine not to boot or to run slowly when it does boot.." so I told him to send the module back and I did refund him as this seems the only fair thing to do. But when I tested the returned module it turned out that it worked without a single problem, concluding that it´s not really faulty  :-o

Can anybody please help me out on this riddle  :-? Is there something wrong with some cards The memory I use is 128 MB RAM SIMM 72-PIN - FPM RAM - 66 MHz - 5V - 60ns - Parity ...

[Karlos]

Hmm.

Has buyer 1 tried each SIMM independently in each socket, or just tried them both in the same socket?

[Effy]

Buyer 1 has tried them independatly, one module on the card and when it works he removed the one and tried the other one on the card. That way each module worked just fine, but not when used together ... have nu clue why this happens ...

[Karlos]

Hmmm, that still doesn't answer the question of wether each SIMM has been tested in both sockets independently. Unless I misunderstand you, that is.

[lordspider]

@Effy:

Does the buyer tried each SIMM in both sockets or only in one and the same socket?

It is important to figure it out, AFAIK some BPPCs can only accept 192 MB RAM.

[Effy]

Think I am the one who misunderstood you. I don´t know if he tested each socket, I only know he tested each module ...

[odin]

Perhaps an in-depth test with memtest86 will find faults in the suspect SIMM?

[x56h34]

The only problem which I experienced with these HP 128MB simms is that some 240Mhz cards while working in PPC mode may crash after a few minutes. Other than that, 68k mode always worked fine and I could see full 256MB ram.

[Karlos]

I've been using a pair of those 128MB SIMMs for a while now and I haven't had any problems with them.

I got them from Haymiggan a while ago. I think they are the same kind, anyway.

[Tahoe]

Are the cards in which they are used set at 60ns RAM? I have a few HP EDO Simm's laying around in various sizes. Although all state they are 60ns (which also works in a PC) my Blizzard worked stable only after setting it to 70ns on some simms.

[Effy]

Tahoe : that´s the first reasonable explanation I have heard that actually makes sense :-D

Sorry, had two major big glasses of red wine and french ries with sardines  :lol:  

[delshay]

the problem may be lack of power..


i have 256MB ram each simm has a tolal of 16 chips..32 counting 256MB..


this is a heavy drain on the 5v line..which can lead to lock-ups when useing 68k & ppc chip at the same time..

also clean the contact.

also when inserting simms try inserting a little to to left or right as the contacts may be dirty..

simm socket may also need cleaning..

[Effy]

And that´s another great explanation !! I always use a tower for testing as I don´t have a desktop anymore so I didn´t think of power supply problems ..