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-   -   [HELP] Short-circuit fault detected when running flashlight (https://talk.maemo.org/showthread.php?t=90476)

Alecsandru 2013-06-16 13:29

[HELP] Short-circuit fault detected when running flashlight
 
1 Attachment(s)
Short-circuit fault detected!
Turning off Flashlight.

I have this pop-up when I use flashlight , the time interval is randomly(from few swconds to minutes or not at all) , when I take photos I have full flash blast(no error) , I don't think it's a hardware problem , no water and no impacts on the phone , this thing started today , any hints on this ?

nokiabot 2013-06-16 16:51

Re: Short-circuit fault detected!
 
Take a tooth brush dip the tip in ethyl alchol clean the board like you brush your teeth but gently with mild preassure and use a needle to clean every contact points you find:)
i think somewhere moisture accmulated and oxydised the parts .
Btw it wont do any harm cleaning it:)

Alecsandru 2013-06-16 17:30

Re: Short-circuit fault detected!
 
I need a hint of what is sensing the short-circuit , the flash pcb is pretty simple ,but what is sensing that short-circuit

nokiabot 2013-06-16 17:48

Re: Short-circuit fault detected!
 
Quote:

Originally Posted by Alecsandru (Post 1352520)
I need a hint of what is sensing the short-circuit , the flash pcb is pretty simple ,but what is sensing that short-circuit

no idea :) but surely somebody here knows it:)
btw its not wise to keep using it like that i think . So i recomended cleaning:)

anthonie 2013-06-16 18:03

Re: Short-circuit fault detected!
 
Quote:

Originally Posted by Alecsandru (Post 1352520)
I need a hint of what is sensing the short-circuit , the flash pcb is pretty simple ,but what is sensing that short-circuit

I have no idea what could be causing this, other than what the warning tells you. I did, however, notice the spelling mistake in "circut" that you yourself I assume auto corrected in the topic title. The only google hits point to the patch for flashlight. Have you seen it?

Have you tried a reinstall to see if the warning popped up again?

Alecsandru 2013-06-16 18:18

Re: [HELP] Short-circuit fault detected when running flashlight
 
I was typing from the phone when I started this thread , the question is: it's really detecting a short-circuit? and if it detects the short-circuit , where is it? how do it get detected ?, reading what , from where? with the help of what? I'm reading the datasheet but no luck yet ,but the software part , from where does the pop-up appear ? how it's triggered ? many questions , to many I fear

Copernicus 2013-06-16 19:30

Re: [HELP] Short-circuit fault detected when running flashlight
 
Quote:

Originally Posted by Alecsandru (Post 1352529)
the question is: it's really detecting a short-circuit? and if it detects the short-circuit , where is it? how do it get detected ?

Ah, I've been playing around with the flash LEDs recently, so I know a little bit about it. I'm not sure how many flashlight apps are out there right now, but I suspect all of them are using the "Video for Linux 2" (V4L2) interface. That interface allows you to query the hardware for a variety of error conditions, including timeouts, overvoltage, overtemperature, and short circuit.

From the ADP1653 data sheet, there is this info about the short circuit fault:

Quote:

Short-Circuit Fault
The HPLED pin features short-circuit protection that disables the ADP1653 if it detects a short circuit to ground at the cathode of the LED(s). The ADP1653 monitors the HPLED voltage once the part is enabled in torch mode. If after 820 ms the HPLED pin remains grounded, a short circuit is detected. INT goes low, and Bit D3 (FLT_SCP) of the FAULT register is read back as high. Avoid false triggering of the Short Circuit Fault by not changing the torch current level while the short-circuit detection circuit is making a measurement of HPLED pin voltage. Do not change torch setting directly between two non-zero torch levels 750 ms to 900 ms after the torch has been enabled. To change torch mode current level between two non-zero torch levels 750 ms to 900 ms after enabling torch mode, use the following sequence:

Torch Current Setting #1
Torch Current Setting = 0
Torch Current Setting #2

Torch mode and flash modes can be enabled or disabled at any time.
It appears that this fault condition is specific towards the use of the LEDs in Torch mode, rather than Flash mode.

So far as I know, V4L2 only allows a single Torch current setting, so you shouldn't be able to cause a false trigger the way that they describe. However, I guess that would depend on how the app is connecting to the LEDs.

Quick question: when this error first crops up, do the LEDs come on for a brief period (half a second or so), or does the error message come up immediately?

EDIT: Ah, actually you've already answered that question in the first post. :) If it was a fault in how the software was accessing the LEDs, I would assume the error message would come up immediately. The fact that the LEDs stay on for a while may indicate that there is, in fact, a short circuit going on somewhere...

pichlo 2013-06-16 21:00

Re: [HELP] Short-circuit fault detected when running flashlight
 
Quote:

Originally Posted by Copernicus (Post 1352543)
The fact that the LEDs stay on for a while may indicate that there is, in fact, a short circuit going on somewhere...

Or a false positive caused by a sudden change in the LED current, such as might happen if the battery is on its last leg. Which might explain the erratic nature of the problem. One question: does it ever happen when on a charger? The solution may be as simple as getting a new battery...

Alecsandru 2013-06-16 21:44

Re: [HELP] Short-circuit fault detected when running flashlight
 
same thing on charger , but a strange problem , the torch lights up only one led while camera fires up both when taking pictures
i'll replace the led , but the problem is that it fires up well when I take photos

Copernicus 2013-06-16 22:10

Re: [HELP] Short-circuit fault detected when running flashlight
 
Quote:

Originally Posted by Alecsandru (Post 1352556)
same thing on charger , but a strange problem , the torch lights up only one led while camera fires up both when taking pictures
i'll replace the led , but the problem is that it fires up well when I take photos

Personally, I doubt that the LED is bad, especially if it lights up when in flash mode. More likely, there is something causing a short circuit -- i.e., something like a fragment of metal stuck somewhere, allowing electricity to flow where it shouldn't.

But I will bow out here; I know a bit about coding, but I have no clue about physically messing around with hardware. :)


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