Okay, by now we all have seen the posts regarding this fix for the display dimmer, the one involving soldering a capacitor onto the display board.

This fix is supposed to prevent the display from showing random levels of brightness as you are adjusting it from the "dimmer" menu.

There is another different problem, one that isn't the same bug. This problem manifests itself as follows: Occasionally (very rarely), the player boots up with the display dim. The bootup animation and custom boot logo will show as being dim. However, when the player binary itself loads up, it resets the display brightness and the display pops back to the correct brightness level by the time the player is done booting.

Here is my question:

Will the capacitor fix ALSO solve this rare "initially-dim" problem? Or does it only solve the random-brightness-levels-when-setting problem?

I've got the "initially dim" problem and I'm wondering if I could fix it by soldering the capacitor into place.

Sounds like a different issue. The boot up dimmer level is probably just random, and could be "fixed" with a one-liner in the kernel. The capacitor fix is for fluctuating dimmer levels..

But I don't really know. Anyone out there know more?

the capacitor is definatly for smoothing out the power. It supplies a more constant voltage to the display. Im pretty sure it wont fix your problem

This is a different problem, which has been known of (and discussed) since the year dot. In fact I would have expected it to be in the FAQ!

All Mk.2 and Mk2A players are potentially prone to this issue, and according to Hugo absolutely nothing can be done about it. The problem only persists during bootup - brightness should be normal after the player has started.

Rob

What about Mark's idea of fixing it with a one-liner in the Kernel? Just send a "brightness full" command just before playing the first frame of the startup animation? Would that work to cover up the problem?

Erm, no, the capacitor fix (across the AD8400 pins) *will* fix the dim-at-bootup problem.

The capacitor fix smooths out any glitches in the AD8400 (digital pot controlling the divider on the VFD main PSU feedback) chip select line. A glitch will affect both adjustments of the dimmer and the initial setting - basically, any time the PIC tries to set a dimmer level. It does this both at startup and when a dimmer command is received from the main board.

Hugo

Ahh.. that explains a few things.. I suppose we oughta make this capacitor a standard addition when installing the buttonLED's.

Cheers

the capacitor fix (across the AD8400 pins) *will* fix the dim-at-bootup problem.

Yay!

/me jumps up and down and claps his hands.

Now to find an appropriate capacitor...