On powerup start screen freezes from time to time

[penlec]

Hi,

I would like to hopefully resolve a situation on power-up that the Startup screen (the blue one) freezes up so the system does not complete its Bootup.

We have connections to all three back USB ports, it appears that after switching off and with any of the three USB disconnected it might Boot correctly, other times it takes several attempts. From time to time it will Boot first time without disconnection of any of the USBs.

The USB connections are: Touch Screen, KBD & Wing

Any ideas what I could look at further? Once running we don't appear to have any further issues although the Touch Screen can stop responding and the only way to get the touch response back is by rebooting the desk, could the problem be related?

Many thanks, Brett (Regal Theatre Minehead)

 

[KWR88]

Two possible issue i can think.

One is a system resource issue at boot up. Basically the processor module is potentially allocating system resource (memory) to something at boot up so it can't initialise itself correctly. This could potentially be resolved by a bios update on the processor module that "caps" the amount of memory it is allowed.

The second is the USB devices, for some reason, pulling the 5v rail down at boot. The 5v rail is critical as it is used to generate internal 2.2v and 3.3v. if it low the other rails will be low and some of the logic will again not initialise.

PM on the address below and we can discuss possible way to solve this. 

 

[kgallen]

Are there internal memory DIMMs that maybe need re-seating?

[KWR88]

Yes there is a single DIMM on the processor module. It is worth checking it just in-case.

From what i have seen symptoms for a DIMM issue would normally be X in the middle of the screen at boot. 

[iank99]

It's likely to be one of the USB devices - not all USB devices are created equal and the current draw on USB devices can vary wildly (and widely).

If your configuration has been working then it might suggest that one of the devices is beginning to fail - if it's a new situation then it's likely that the Keyboard (it's often the keyboard) may draw too much current.

"The USB specification allows for up to 500mA of current to be delivered from the USB port. Portable devices are increasingly using the USB power provided by a host computer to power the device system bus and to charge batteries."  - Source

This was a common problem back when LeapFrog/Solution was first launched and folks were plugging in the first keyboard they could find, their USB coffee warming and their iPad