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View Full Version : Libretto 70CT unstable, fails Memtest86:



manimal347
April 4th, 2011, 10:44 PM
I'm having some issues with my Libretto 70ct, and I figure I should get some advice before I venture too far. Basically, the first issue is with the LCD. Often, I'll see faint ghosted lines of a window, continuing past the window. For example, if I minimize a window, I may see a faint ghost of the Win 9x tooltips and grey vertical lines used for resizing. Also, I usually see faint rolling lines on a blank and solid background such as the standard green Win 95 desktop. They look rather much like what one might see if they used a cheap VCR as a TV tuner or were watching TV while a game console were hooked up via RF but not tuned in.

Second issue: system instability. While pretty solid under 95 and Debian Sarge, the computer is very flakey under Win 3.x and MS-DOS. I've observed the following and more: Magnaram causing many crashes under 95, all browsers but Netscape 3.04 crashing wildy under 3.x, QEMM 97 causing myriad crashes under MS-Dos 6.22, protected mode programs hanging the system when closed under EMM386 - and particularly disturbingly, system hangs at the dos shell or under EDIT with autoexec + config.sys bypassed. QEMM tended to alert me of what I believe are CPU errors. It would throw up hex registers when it trapped a program (freq. Links 2 browser). I know Windows 3.x was never a stable OS, but if most people found 3.11 for Workgroups *this* unstable, I think we'd have had poor office productivity and a rash of employees going postal on IT staff. Seriously.

Now, the real cause for alarm. I ran memtest86+. Twice. My CPU halted. Twice. Memtest86 4.0 reported an interrupt fault and stated that CPU 0 halted both times, complete with the same hex. Different hex than Qemm threw up, though. Memtest86 did not report memory errors, and made it through 75% and 92% respectively, both aborting in the first pass.

I've seen nudie shots of the Libretto's motherboard, and it's a land of SMD components. Thus, I'm hoping it's a power issue - either the brick, or the internal regulator. Given what I'm experiencing, is dirty ripple-laden power the most likely cause? Even probable?

NathanAllan
April 6th, 2011, 12:06 AM
Is the memory replaceable? Try replugging anything that can be unplugged. I have yet to take apart my Libretto. Not sure how they look on the inside.

Raven
April 6th, 2011, 09:38 AM
The "CPU errors" can be caused by RAM issues, as could the screen issues, depending on the system's architecture and what particular set of software is running (drivers, etc.). It's hard to say without isolating the memory problem first.

If memory serves the memory is replaceable, but it might be a situation where one stick is swappable but one is soldered-in - if so, then the problem is (unfortunately) likely with the soldered one (whichever is "bank 0"), otherwise the crashes and issues would be relegated to particularly memory hungry programs only, not anything using EMS/XMS/Win32 RAM above 1MB.

manimal347
April 6th, 2011, 05:11 PM
I've indeed come to the same conclusion. Win 95 throws the occasional page fault. Suppose the system freaks out when it looks for something in physical RAM, then can't read it bit-perfect. Would certainly explain Qemm 97's dramatic explosions - such a ricey memory manager wouldn't play well on marginal hardware. Too bad, as the stock memory comes soldered to the motherboard. If I recall correctly, two dainty little ICs. No way to underclock the RAM, else I'd try that. Just might work on a tower system with a feature-laden BIOS, but not the Libretto's featureless setup program. I figure I'll just buy a parts 50CT or 70CT with the 16MB RAM expansion module. If the parts/gutted ex-corporate machine is in good shape and just needs an AC adapter, HDD and or battery, I'll switch over to it. Otherwise, I guess I can swap motherboards. Too bad Librettos never seem to show up with smashed LCDs and/or broken hinges...

manimal347
April 6th, 2011, 05:15 PM
On another note, I'm downgrading to OSR1. Could be mistaken, but I seem to remember from back in the day that it had a smaller footprint than OSR2.5. Nobody on Usenet explicitly states this, but there's plenty of references to 95 running okay in 8MB of RAM - all from prior to OSR2+'s introduction.

Tetrium2
April 12th, 2011, 06:46 AM
If I were you, I'd start by replacing the memory. Theres no point in trying to make broken hardware work, in the end you'll be wasting a lot of time.

NathanAllan
April 14th, 2011, 05:51 PM
Is the memory replaceable?

EverythingIBM
April 15th, 2011, 08:35 PM
Is the memory replaceable?

I was looking at some sites and they all say the 50 and 70 models can be upgraded with an extra 16 MB of memory.

And here's nathan allan on his libretto:
http://i.ytimg.com/vi/i6Jo89Ih9LI/0.jpg

angel_grig
April 15th, 2011, 10:00 PM
I've indeed come to the same conclusion. Win 95 throws the occasional page fault. Suppose the system freaks out when it looks for something in physical RAM, then can't read it bit-perfect. Would certainly explain Qemm 97's dramatic explosions - such a ricey memory manager wouldn't play well on marginal hardware. Too bad, as the stock memory comes soldered to the motherboard. If I recall correctly, two dainty little ICs. No way to underclock the RAM, else I'd try that. Just might work on a tower system with a feature-laden BIOS, but not the Libretto's featureless setup program. I figure I'll just buy a parts 50CT or 70CT with the 16MB RAM expansion module. If the parts/gutted ex-corporate machine is in good shape and just needs an AC adapter, HDD and or battery, I'll switch over to it. Otherwise, I guess I can swap motherboards. Too bad Librettos never seem to show up with smashed LCDs and/or broken hinges...
As far as I know Libretto came with 16 MB on board memory.I upgraded mine with an original memory module from ebay 5-6 years ago.In my L70 I'm using a dual boot win98-DOS 6.22/win 3.1 setup without any problems (and it is overclocked to 166Mhz).If you want check out here the original L70 service manual http://www.silverace.com/libretto/libmm.zip

NathanAllan
April 16th, 2011, 11:59 PM
I was looking at some sites and they all say the 50 and 70 models can be upgraded with an extra 16 MB of memory.

And here's nathan allan on his libretto:
http://i.ytimg.com/vi/i6Jo89Ih9LI/0.jpg

That pic was supposed to stay under wraps, DOH!!! Like my fancy watch? Wokka wokka!

manimal347
April 19th, 2011, 12:18 PM
Honestly, consider this thread closed. I have a game plan, which I've already laid out. I'm just going to wait until a broken
down 70CT with 32MB of ram shows up on Ebay or such. Then, I'll just bring my power brick, hard disk, screen, .etc over to the "new" unit. All I really need, as it stands, is a 70CT motherboard and the 16MB upgrade module.

twolazy
May 23rd, 2011, 03:56 AM
Well reading this thread, maybe its not the memory chip, but aged caps? If it was my machine, before i try soldering in any new ram to repair it, (which isnt as hard as you think with lots of flux), I check all caps/mosfets leading up to the ram. Knowing of the capacitor swindles of the late 90s/early 2k, My money is on a dried up cap...

On a side note, if you do wish to replace the ram chips, I might have some that are a perfect match, just pay for shipping. You have to open up this pcmcia looking memory upgrade, for my old P1 toshiba. Inside are 8 ram chips if I recall correctly, totaling 32mb. 4mb each. Is your machine 8mb stock?

Raven
June 11th, 2011, 01:25 PM
On a side note, if you do wish to replace the ram chips, I might have some that are a perfect match, just pay for shipping. You have to open up this pcmcia looking memory upgrade, for my old P1 toshiba. Inside are 8 ram chips if I recall correctly, totaling 32mb. 4mb each. Is your machine 8mb stock?

1. Do you still have this Toshiba? I like Toshiba laptops from the 90s.. shouldn't be buying any more machines, but I'm curious anyway..
2. Does this module say what models it works with? I have a T6600C that could use a RAM upgrade and takes up to two of those modules - I've got two 8MB modules in it ATM, plus the onboard.

twolazy
June 12th, 2011, 06:25 PM
LOL I know the feeling! I own quite a few ancient laptops... Sadly no, I no longer have the machine. It had an accidental mishap with my son, and 2 flights of stairs ... :S
Machine died, somehow the lcd manged to stay intact though!

As for what the card work with, here is what I could find...

Simple Technology
STT4700/32
32 MB Toshiba memory card for Toshiba T4700/4800/4850/4900

Believe it was from a T4900. My cross-reference shows a T6600C takes 72pin EDO Sodimm modules. I believe I have some of those. 32mb/64mb each. Should share same memory as thinkpads, and my T2160CS.

NathanAllan
June 14th, 2011, 05:45 PM
Toshibas are tough machines, and every one of them has worked that I have owned, even through all the abuse I accidentally put to them. Not surprised the LCD survived, it has a pretty tough outer case on it.

twolazy
June 15th, 2011, 09:31 PM
I just had a strange idea that might just get you back a functional unit!

Since its been assumed (at least hope this is true) that the on-board ram is going bad, wouldn't it be possible to just remove the Vcc pin from the on-board ram. Like take a soldering iron, and lift the pins so they do not make contact. Then if you popped in a simm, it should detect just that ram, and not the on-board. Wouldn't be that hard to do, and get you back a working unit provided you have a simm for the machine...