Toshiba M45-S265 power problems

[ComputerClinic]

When I first got the computer, it wouldn't power on at all. No lights or anything. The client said the DC jack was loose so no surprise there. I take the machine apart to find the DC jack is on a harness so of course isn't as tight as one soldered to the board. I test the voltage and all is well there. While I have the machine apart I clean out the HSF and reapply thermal paste. Before I reassemble the machine I plug the RAM and AC adapter in and now there's a light, and the machine turns on just fine. Hmm...I add each component back one by on and the machine keeps powering on just fine and eventually the whole thing is back together and its working great. So I start tuning up the computer, thinking maybe there was just a loose cable or something. After 2 or so hours the machine just shuts off. There are no lights on the front and it won't power on at all. Couple of hours later, one of the lights turns on and the machine powers up just fine. What should I do next? I'm thinking it must be something with the motherboard?

 

[NYJimbo]

Start over.

Record your entire diagnostic process.

A laptop that shuts down after running an hour or more is going to be a pain to troubleshoot. If it isn't thermals or something obvious, like something you just ran or something you find in the event logs, this will be alot of fun.

Enjoy......

 

[ComputerClinic]

That's the problem, I haven't really done any diagnostics because I don't know where to start. I thought it was a DC jack problem but that's not the case. I'm positive its a hardware issue but I would like to pinpoint exactly what's wrong rather than just replacing the motherboard. It doesn't just shut down, it shuts down and won't turn back on for hours. I mean the motherboard completely stops working. Then out of nowhere it will turn on again and then shut down again hours later.

 

[dmurphy315]

start with testing the memory modules, swap out one at a time, change dimms, re-seat etc......... test in another laptop or when this one does power on.
OR try different working memory if you have available and see what happens. memory or one of them could be crappin' out not going get any lights if you pull all memory out, so test start with the memory........... thats where I'd probaly go next anyway

had one last month that would shut down during the mem test or just as i started the mem test,, with both modules in one at a time to.... at one point the screen began to artifact, i thought vid card or cpu heat, but no excessive heat,, still cleaned the heatsink and fresh artic silver etc... it only artifact when i attempted to run the mem tests

pulled memory from another laptop and the tests ran clean, no artifacts on the screen no shut down during the mem tests,, laptop was good................... both mem sticks were bad.

check the cord to while your at it,, maybe thats going in and out and not fully charging the battery? or the battery old and won't charge, power cord goes out and laptop shuts down.

whenever a dc jack scenario comes to me,,, i try to test make it a point to test the power cord real good,, try different memory, pull the hard drive, pull the cmos battery (or desolder cmos battery), pull the battery before taking the laptop FULLY apart and going after the dc jack.

had one months ago, cord tested good, jack felt loose (not a harness jack), wiggle the cord and jack around it powered on. dis-assembled laptop, held cord in a certain position, had power inside,, desoldered jack and replaced, tested same problem................ ended up being the cord from the get go! the very end of the cord, that "boot" just before the cord "jack" plug, somewhere right there was shorting out in the cord. when i kept the end cord plug steady and moved the cord itself closest to the end plug on the cord, i lost power on the meter.


www.LaptopRepairAugusta.com

 

[ComputerClinic]

Sorry for the lack of input on my end. Its the weekend and I won't be dong anything with this machine until later tomorrow. But I'll try and clear up my original post a lil:

I'm pretty confident it is either the AC adapter or the motherboard. There is a light on the front of the mobo that lights up when the adapter is plugged in, but when the problem is occuring, there is no light. This light would come on regardless of if the RAM was good (but to be positive, I did test with working RAM and CPU).

Here are the symptoms again:
-laptop will work fine for hours
-laptop will shut down and not power back on for hours (no lights either)
-laptop will randomly start working again

These are not the problem:
-DC Jack
-Memory
-Processor
-Thermal Problems

Here is what I plan on doing tomorrow:
-strip down computer to just motherboard, CPU, and RAM, and CD drive
-put in working CPU and RAM
-Boot to my WinPE CD and run stress tests until the laptop decides to shut off
-When it does shut off, I will test the voltage near the DC jack to see if the AC adapter is still putting out power
-Then I will know if its the mobo or AC adapter

I would just test the ac adapter externally, but I cant seem to get any readings off of it even when it is working. I've run into this sometimes and I just cant figure out where to touch the multimeter to.

Now, if it is a motherboard issue, I see this as a great opportunity to learn (even if I do end up replacing the mobo). I would like some help finding out what component needs to be replaced. If anyone can give me some tips or maybe a link that would be great.

 

[Larry Sabo]

I have a Toshiba Satellite M55 I think (it's in a case and I'm too lazy to dig it out) that does the same thing. I gather that this is a common Toshiba problem. I've stress-tested this thing to death and it wouldn't fail. Time before last, it would go stone-cold-dead if I move the hinge or tilted the laptop. I thought, "Good, something to troubleshoot." Fired it up yesterday and it ran perfectly for hours, flexing hinges and shaking be-damned. A customer gave it to me because he had taken it to a number of techs and none of them could fix it. I loaned it to a customer and he said it would work for a while then go blank. I suspect it's a bad cable or bad solder joint (not just GPU--the whole thing goes lights-out dead) and have considered reflowing the MB, but I'd really like to find the smoking gun (exact fault), as I call it.

Sorry that doesn't help, but I thought it would help a little know you're not alone with this problem.

 

[ComputerClinic]

Well its been running all day and hasn't shut down yet. I'll continue to let it run overnight and see what happens. It's a pretty old machine so I'll be recommending a new computer and data transfer if I can't reproduce the problem and be there to test the voltage when its happening.

 

[ComputerClinic]

Well, I bumped the AC adapter and it died. Jiggling the cords doesn't make a difference, but shaking the box will kill it. Well, it's worth fixing after all.