STM CircleOS forum / Primer 2 Blank Screen

tkerby · 2009-04-16 09:46:21

Hi
The primer 2 I just received has a blank screen when it pwers on - totally white, backlight on.

I've tried restoring circle to factory settings but get no change.

I'm probably missing something but any help would be appreciated

Saulis · 2009-04-16 14:12:15

i think that lcd connection has broke. first you need to dissasembly and chek lcd connector vissualy(actualy its not a connector, because its soldered to the base pcb.

on one of primers2 after some experimentation screen started to show *snow*. electrically found that on lcd connector one capacitor had loose connection(its in charge-pump circuit)

Last edited by Saulis (2009-04-16 14:14:24)

tkerby · 2009-04-16 14:18:22

Looked visually ok to me. I'm undecided as to whether I should send it back to Farnell or try to reflow the connector. Previous experience of soldering to lcd connectors has been that they dont take the heat well

tkerby · 2009-04-16 15:23:41

Looks like c12 was missing on the flex and had got into the back of the lcd itself where the flex enters. It's going back to Farnell for a replacement as it looks like the pads are torn. Seems to be that the cap was too close to the radius of the bend in the flex

Francis · 2009-04-16 16:26:18

The factory found the issue with some LCD (I believe 2 caps may touch each other because of the low radius). In this case, it generally works when the box is opened, and fails when the screen is pressed by the box.
What is strange is that it worked during the factory tests, ... Anyway, you can also ship it back to Raisonance, and we'll repair it.

Saulis · 2009-04-16 18:24:55

these two caps i believe works in charge pump or dc-dc converter circuit, because then I opened it, found some dirt on them.

# 1 2009-04-16 09:46:21 Primer 2 Blank Screen

Primer 2 Blank Screen

# 2 2009-04-16 14:12:15 Primer 2 Blank Screen

Re: Primer 2 Blank Screen

# 3 2009-04-16 14:18:22 Primer 2 Blank Screen

Re: Primer 2 Blank Screen

# 4 2009-04-16 15:23:41 Primer 2 Blank Screen

Re: Primer 2 Blank Screen

# 5 2009-04-16 16:26:18 Primer 2 Blank Screen

Re: Primer 2 Blank Screen

# 6 2009-04-16 18:24:55 Primer 2 Blank Screen

Re: Primer 2 Blank Screen

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