This video isn’t going to win any awards. It’s only 13 seconds long, and is hyper-grainy. But if you peer closely, you can see my Nokia E72 displaying a bizarre kind of visual hiccups.
A brief bit of history: the E72 unfortunately became waterlogged. (Ahem. Old habits die hard.) I took out the battery immediately, and left everything to dry out in an airing cupboard. After putting the battery back in and restarting the E72, things initially looked fine. The device booted OK, and I could start navigating around the applications.
But about one minute after booting up, the display starts doing the kind of weird vertical jitter you can see in the video.
This display malfunction reminds me of my childhood days, when TVs would sometimes experience problems with their “vertical hold”. In that bygone era, there was usually a “vertical hold” button you could twiddle on the back of the set, to fix that problem. (Note to younger readers: this was before the advent of TV remote controllers.) However, although the E72 has lots of keys and buttons, none of them is labelled “vertical hold”.
It also reminds me of one more thing. This kind of vertical jitter is, sometimes, part of the normal display on my E72. But it usually only happens once at a time, rather than getting stuck in a loop.
Does anyone have any idea what causes this vertical jitter?
I’m hoping for a more precise answer than “water damage”. I think there must be at least some software aspect to it:
- The jittering doesn’t start immediately when the device boots, but only after a delay. It looks like it’s triggered by some of background software process, which eventually kicks in
- The speed of the jitter changes, depending on what else you do with the device. For example, if you start a new app, the jittering temporarily stops, but then restarts
- Whenever the jitter is occurring, the multi-coloured Nokia rotating “busy indicator” icon (I think that’s what it’s called) is just about visible on the title bar, suggesting that the device is trying to do something.
I wondered if there was anything in my own phone’s setup (e.g. the apps I had installed) that might, somehow, be causing this behaviour. So I went back to the factory settings. However, this didn’t cure the hiccups.
Almost certainly, I’m going to have to give up on using this particular device, but before I reach that outcome, I’m hoping to find a way to stop this behaviour!
In the meantime, I’ve been struggling to use an N900 as my primary smartphone. It’s an interesting experimental devices, but it’s miles away from being ready for main-time usage.
Added later: Thanks to @taike_hk for suggesting the use of a microscope, distilled water, alcohol, and a hairdrier. (But I don’t particularly relish the thought of disassembling my E72…)
dw2 
My instinct on seeing that is to suspect the power supply – it looks like the heartbeat of a charge pumping element, so perhaps there is a component in that circuitry not fully dried out.
When you start applications, that changes the power demand and perhaps allows that circuitry to temporarily perform better. Does the behaviour change with external power connected?
In any case, I’d suggest giving the device more drying.
Comment by Pute — 5 December 2010 @ 12:51 pm
Interesting…
When the standard charger is plugged in, the behaviour is exactly the same.
But there’s one difference when a USB cable is connected. The E72 puts up the usual dialog for that situation, asking the user to “Select US mode”, giving a choice of “PC Suite / Mass storage / Image transfer / Media transfer / Connect PC to web”. But for as long as that dialog is showing, the flicking completely stops. It’s only when the user in due course makes a selection from that dialog, that the flickering restarts again. This suggests that some software thread is held up, while that dialog is showing, and this this is the thread which is causing the screen flicker.
(Incidentally, the E72 starts drawing power from the USB cable, in this situation, immediately the cable is connected, rather than waiting for the dialog selection to be made.)
Comment by David Wood — 5 December 2010 @ 5:02 pm