Wierd Toshiba 1905-S301 Laptop Behavior

On Sun, 10 May 2009 18:39:45 -0400, prc1 put finger to keyboard and composed:

Is it possible that your CPU is being throttled because of heat or some other reason? You can use a utility such as RMClock to display the CPU speed.

See this Usenet post:

- Franc Zabkar

I have a Toshiba 1905-S301 laptop that had its power supply blown up in a lightning strike. I've gotten a new replacement adapter, and the unit seems to be in great working shape.

Except...

I noticed an oddity when downloading some patches off a wired ethernet connection the other evening. When the laptop has just been turned on, everything's great--surfing and downloading speeds are super. Then, after a while, internet access s-l-o-w-s down. New websites are slow to load, downloads that were flying begin to creep...

...until I unplug the AC adapter. Then the speeds pick back up, sites load quickly, downloads are fast.

I've stripped the unit down to the system board and looked carefully with a magnifying glass. I can see no obvious problems (burnt traces, cracked components, et cetera). Everything else on the unit's A-OK.

Has anyone else experienced a problem like this?

probably spyware or a system process that turns on automatically. There could be any number of reasons. But if it works fine when not connected to the internet it probably not hardware related.

Thanks for the replies thus far.

The poswer supply is an exact replacemtn, sec-wise: 19V @ 4.75 A (90 watt).

The hard drive was replaced with a newer, bigger hard drive and has a fresh install of WinXP SP3, with patches. I'm also running Pop-Up Cop to help with spyware, but I hadn't visited any other sites than Microsoft's Adobe's and Apple's (still installing players, et cetera).

I found a SpeedStep monitor/control program, but it will only show the full-out speed (1.993 GHz) of the CPU. I'm guessing the machine has a desktop processor in it--when I removed the heatsink to clean it and re-grease the CPU with Artic Silver, it looked like a desktop CPU.

The mystery deepens...if I only had a schematic. :(

How much System RAM? Have you looked to see what programs are using the most memory? Some web pages have so may scripts running that they hog all the resources, and slow a computer to a crawl.

Before you start worrying about the electronics, check your power management settings with the Toshiba utility program. It sounds like you might have configured AC power mode with low power settings (eg; low CPU usage). Also, does the AC plug LED light up when you plug in the adapter, & turn off when you remove it?

That's what it sounds like to me too. Toshibas have a special power utility that hooks into the Windows power management system that you can use to check/change CPU throttling, etc, in the various power modes. Oh, & it's also worth checking the BIOS power management settings too.

Sounds like a motherboard issue. I owned one Toshiba laptop back in

On Sun, 10 May 2009 18:39:45 -0400, prc1 put finger to keyboard and composed:

Why not run some benchmarks on the CPU, memory, graphics card and hard drive before and during the slowdown?

If it is only your Internet speed that drops, then check your modem's diagnostics for an error count.

- Franc Zabkar

prc1 wrote: [Please don't top-post!]

Did you make sure that you checked the *Toshiba* power management utility, rather than the Control-Panel one? Try twiddling the settings & re-saving them, just to be sure that they haven't been scrambled.

IME, Toshiba NICs aren't the fastest in the world, but they're not crap.

Bob--

Yep, tried that. No change.

Weird. I've got to say that it doesn't look even slightly like a hardware fault. I think it's going to turn out to be a software problem of some kind. You could eliminate/confirm software by booting the laptop from a Linux "Live Boot" CDROM, & seeing if the problem goes away.

Bob--

I just tried loading an Ubuntu 8.1 live CD, then attempting the download. D/L speed was about 14K/second over wired Ethernet (slow!) and started bogging down at about the 30MB mark on a 140-odd MB download. It finally locked up and stopped downloading about twenty minutes (and a few MB) later. The machine itself, however, would still respond to mouse clicks, opening other windows, et cetera.

Sorry it's taken me so long to get back to you. I've been too busy to read the group until now.

Really weird. Your Internet connection is ADSL, right? Is there any chance of you trying another computer on your modem? I ask because I've seen symptoms like that on ADSL/Cable modems, but never with hardware problems on a PC. The test will tell you whether your modem (or ISP!) is the problem, or whether you've got an unusual fault in your laptop.

Hi, Bob.

Nope, I'm on a cable modem. My other computers on the network work just fine with it, so it's not that interface. Wireless works A-OK too--just the wired network connection misbehaves when the laptop's on AC power.

prc1 wrote on Sat, 30 May 2009 22:31:49 -0400:

Sounds like a ground loop problem. Does the cable modem or the laptop have the three prong power plug? If so, get one of those 3 prong to 2 prong adapters so you can temporary disconnect the ground prong to see if the problem disappears.

Have you tried updating the NIC drivers?