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Generic AC adapters, and the problems they cause
Posted: Mon Nov 03, 2014 8:41 am
by that1nerd
Recently, I've been working on a TP 770x that I just purchased. The backlight in this particular laptop is nice and bright, and doesn't show signs of failing. So imagine my confusion when the backlight would go out at random.
It took me a while to piece it together, but I discovered that it would only happen when I plugged in a cheap Chinese generic AC adapter, that I happen to have, into the laptop. When I used the OEM AC adapter for my T43p, the backlight works just fine.
I would like to see if anyone has experienced the same problems with these generic AC adapters, so I have an excuse to throw this thing out.
Re: Generic AC adapters, and the problems they cause
Posted: Mon Nov 03, 2014 12:25 pm
by mpcook
that1nerd wrote:
I would like to see if anyone has experienced the same problems with these generic AC adapters, so I have an excuse to throw this thing out.
Yes, throw it away. OEM only.
Re: Generic AC adapters, and the problems they cause
Posted: Mon Nov 03, 2014 1:05 pm
by that1nerd
mpcook wrote:Yes, throw it away. OEM only.
Oh, trust me, it's being deep-six'd.
It's just that I'm a very inquisitive person, so while most would just throw it away and be done with it, I'll take a predicament like this and turn it into a learning experience.
So my question is what would cause the inverter to stop running like that. Do these generic AC adapters put out excessive noise or something?
Re: Generic AC adapters, and the problems they cause
Posted: Mon Nov 03, 2014 8:56 pm
by tfflivemb2
That makes TOTAL sense ! I was really worried about the backlight thing, because I never had issues with it. Fluctuations in power can cause issues like that. I've had a few non-oem chargers cause power related issues, albeit not with the backlight.
Re: Generic AC adapters, and the problems they cause
Posted: Tue Nov 04, 2014 9:02 am
by that1nerd
tfflivemb2 wrote:That makes TOTAL sense ! I was really worried about the backlight thing, because I never had issues with it. Fluctuations in power can cause issues like that. I've had a few non-oem chargers cause power related issues, albeit not with the backlight.
Even when the backlight came up on battery power, as soon as I plugged the AC adapter in, the backlight would immediately go out. Only a reboot with the AC adapter disconnected would allow it to start back up. That's how I ended up piecing together what was causing this problem. I'm just glad it wasn't a backlight or inverter issue.
My theory is that the generic AC adapter would hit a certain harmonic frequency that matches the inverter, and would disrupt it in the process. I don't have a way to prove this unless I can get my oscilloscope back (and pull up some spec sheets on the inverter).
After this "revelation", I've been using my T43p's AC adapter exclusively to run it until I can get my hands on an original AC adapter.
Re: Generic AC adapters, and the problems they cause
Posted: Tue Nov 04, 2014 9:44 am
by tfflivemb2
Power can certainly cause the oddest problems. I was looking at my 750P that I just sold, thinking it was bricked, because it wouldn't boot....removed the battery, and bammmm it booted!
Re: Generic AC adapters, and the problems they cause
Posted: Tue Nov 04, 2014 10:04 am
by that1nerd
tfflivemb2 wrote:Power can certainly cause the oddest problems. I was looking at my 750P that I just sold, thinking it was bricked, because it wouldn't boot....removed the battery, and bammmm it booted!
It's amazing how a dirty power signal, or a flaky battery, is all it takes to bring a PC to it's knees.