CF-18(DHAZXG2) onboard RAM failing, way to disable?

Hello,

On Toughbook CF-18(DHAZXG2) memtest is giving many errors.. and the notebook itself is crashing/freezing when working, which is normal considering the fact with the ram. I did the test without any ram in the expansion slot.

Do somebody have ideas if is possible to disable the onboard RAM via shortcuting some pins or in any other way? I haven't read the manual yet.. the notebook is owned by a friend of mine, but I assume the onboard ram is not removable (not in a slot).

Any advice is appreciated. Thanks.

 

There is a slot for removable ram on the CF-18. Its under the speaker on the bottom. Your model number is an odd one, but if the machine has more than 256mb of ram showing in the bios it has a stick in the slot.
CAP

 

As I said, I have removed the mem module which is under the speaker, and did the memtest without it. I'm getting numerous amount of errors. I have 256mb ram somewhere inside the box. I'm asking if i can somehow disable it.. And use only the extended one.

As for the model number it is as per the label on the bottom of the notebook.

 

Guess I misread your post. Someone talked about disabling the on board ram on a CF-29 to increase his total capacity but I don't believe anyone ever got up the nerve to try it. I can't think of any other solution to bad on board ram other than looking for a new (used) mobo. Maybe someone else has had a similar problem and it turned out to be something other than the ram. Good luck.
CAP

 

Yes, i suppose mobo change, though hoping for some luck to go without it.

Anyway, thanks for your replies.

 

Had u checked the temperatures and voltages?
Had he/u opened the shell?

It's rare, that the ram itself will fail.

 

I bought a CF-18 with the same issue... It is now a parts machine. It had bad onboard RAM.... No way (to my knowledge) to easily remove the onboard RAM...

 

If the motherboard is bad, it might be worthwhile to experiment and see if you can disable the on-board RAM. What will it cost you bot time? You might be able to have a good bit more RAM then you have now if successful and save the cost of a Motherboard.

 

Another possiblity is to remove the ram chips altogether and see what happens. By far the easiest way is to use a hot air smd workstation. You can find these on eBay for less than $100. You can find videos on YouTube on how to do this.

 

Thanks to all for the tips.

Temperatures should be fine, machine can run continously for hours (e.g. on boot screen). And also the errors appear immediately when the machines is started, after being off for one day.. Dunno how to check voltages.

Well, if I understand correct you are suggesting to use a device (hot air smd) to extract the onboard ram from the mobo? Will the machine boot then with the memory in the expansion slot without any other modifications? Do you have such experience?

I'm not really sure what you mean/suggest. If you can explain it in simple words. Thanks anyway.

 

I would think that if you remove the onboard RAM chips, the system would then act like the majority of computers out there without the onboard RAM. You must have something in the DIMM slot. I don't have any junk boards to try it out but I think it would work.

If this does work out maybe we can then try this out on some of the MK4s and MK5s out there to see if we then upgrade the RAM to 2GB regardless touchscreen or not.

 

Did u got any BEEB-ERRORS?
Had u started an self-diagnostic?
Had u or someone else opened the chassis? Are the thermal-pads on the top of the chips (i.e.CPU and so on) in a good shape and condition?
If u are not firm with an multimeter and oscilloscope, it would be impossible to check the voltages for u. Call a friend

 

No beep errors.

I'm not sure how to start self-diag. I read somewhere Fn+F7 or Ctrl+F7 on the boot screen (centrino emblem.. etc).. but nothing happens. If this diag is supposed to be on some system hidden partition on the hard disk, disk has been reformated and is empty..., so no chance.

I doubt that it has anything to do with temperatures.. in bios it shows that it is normal. As i said, when i boot memtest usb disk and the test will start it produces many errors. So I'll try the trick with hot air smd at one friend's place. Just I'm not sure if it is going to start without the onboard ram. Also may be we can remove only the failing chips.. not the whole on board memory ? I dunno if somebody did something like this.

Is somebody able to provide me a technical spec. (.pdf) of the motherboard? To locate the on board RAM in an easier way. I went to panasonic.com but there were some registrations and i was lazy to go through all the process...

 

When it comes to toughbooks the first thing you do is join / register and its free. You can get all the drivers and manuals your want and if you still have a problem we are here to help but never say your lazy ........it might give us the wrong idea about u and your questions might go unanswered ....... .......... ........... ....... ... ....

PS:This is a great thread and we would love to figure this proplem out , this has been asked many times before and still no one has came up with a solution as far as I know.

 

I got your point.. it is more related to some phobia from "registration processes".. i'm just fed up with these everywhere, otherwise i'm also curious to find solution to this problem.

Anyway, I won't be present for a week or two, but as soon as I have some results.. (if any) i'll post back here.

Thanks community here for the support provided.

P.S. by the way the forum member "onirakkiss" send me some pdfs after my request, but they are listed to be for CF-19 toughbook model. I'm not sure if CF-18 and CF-19 are similar machines.. or same.

 

No, they are not the same. It was my fault, coz I was sending the cf-19 pdf to an other person and so I had sended it also to u. Big sorry.
But can give u the right schematic later today....if u want.

 

To share interesting info.. and to demonstrate power of Linux, one can use the "memmap" Linux kernel boot parameter in order to "disable" some failing memory addresses, which can be at first found with memtest for example.

Now I'm running ubuntu 10.4 on the cf-18, very cool.

 

That's great , all is well I guess.

 

Yes, it is running smoothly. Before that the notebook was unusable. One has to use also the boot parameter "i915.modeset=1" for ubuntu 10.4 otherwise the Intel 855GM is not recognized correctly.

Now I'm a bit reluctant to try the operation with extracting memory banks with hot air smd,, since I have a working machine. As far as I understood from this thread nobody here has shared experience doing that ? I'm not so familiar with the internal organization of the chipset, but what about the "shared memory" that the video card does use? Would it start to "use" from the expansion slot..

I registered on panasonic.com but was not able to find good schematics of the mobo. Only some user manuals.

 

We extracted the memory chips with hot air smd and the result is not much promising for now. I'll describe the steps:

1. We removed one of the chips of the onboard memory (we don't know if is the first or the last.. ) and machine was not able to boot any more with the onboard memory only, result was black screen, no bios/post messages. In this situation we put 512MB memory in the expansion slot and machine started bios/post etc.. but it was thinking it has 768MB (i.e. 256MB onboard + 512MB expansion slot), even though there was one missing (32mb) memory chip from the onboard. Of course result was crashing machine..

2. We removed more of the chips actually at first we were seeing only 4 mem chips just below the expansion slot.. we removed them all and result was as in step 1, machine booting only if there is mem in the expansion slot and still thinking the 256mb onboard are present.

3. We found out that there are another 4 mem chips on the back side of the mother board, so all chips are 8x32MB. We exctracted them too, but now results is that machine would show blank screen (no bios/post) doesn't matter if with expansion ram or not.

So we are kind of stuck at this point.. may be there is some possibility to shortcut pins or other hack, so that the onboard memory will be bypassed on another level.. I dunno.

Any ideas?

 

Did you also remove the ram EEPROM with the spd written on it?

 

I would say, this is impossible, coz the BIOS tells the ICH4-M how to address the onboard memory, isn't it right?

 

Hmm, I'm not sure about such an old chipset, but shouldn't the timings, voltage and other info be stored on the SPD EEPROM?

There should be one EEPROM also on your other ram ( what you put in the expansion slot).

 

Well, probably this could explain the reason, we only removed the 8x32mb chips. Is it easy to recognize this eeprom chip with spd? The machine is not infront of me currently and I'm trying to check a Service manual for this type of notebook but i'm not finding anything.

 

I had send it to u one week ago...

 

Yes.. thanks a lot, I'm checking exactly the one that you sent me.. though it looks is for mk1, mine is mk4 (if i got correctly the convetion), may be it is not important for this case.

Anyway I cannot find the eeprom spd for the onboard on this schematics.

I registered also on panasonic.com as anohter forum member suggested, but there are no service manuals, just operating and reference.

 

http://www.intel.com/assets/pdf/datasheet/252615.pdf ; point 6.3.2

 

I would think that it might be hard, since there would be some other similar chips on the motherboard.

It should have 8-pins (maybe). So I would find all the chips with 8 pins and google whatever is written on them to see if one is the right spd EEPROM.

 

I fear that your problem is still going to be the same even after you do remove that chip; as the memory mapping to associated DIMM slots is in the BIOS binary, and the built-in RAM will ALWAYS be addressed as DIMM 0...

mnem
Good luck widdat...

 

The chipset in the CF-29 and perhaps the CF-18, will allow 2GB to 2.25GB of RAM. To do this on a computer with more then 256MB on the mainboard would require that you disable the on-board RAM, just like you want to do. The problem is that nobody knows how.

(What is the CF-18 chipset on this model, anyone know off the top of their head?)

 

My guess is that the limitation is in the bios. You would need a modified bios or modify the file yourself and re flash your own. I am not a programmer so this is the limit of my information or disinformation as the case may be.