DLPC350: Light Crafter 4500 EVM doesn't connect via USB, RED LED on back

Apologies, some of the message got cut off, the full message is below:

Hi,

I have the LightCrafter 4500 evaluation board, and have been using it successfully for a while. However recently I have had trouble uploading new firmware to the device (having the same problem as, for example e2e.ti.com/.../1652395 .
The problem was intermittent to begin with, getting progressively more common, and now I cannot connect to the board at all via USB.
Then it is plugged in the green LED that usually displays on the top of the board no longer lights up, and on the reverse of the board, an LED by the ribbon cable shows a steady RED.

Could you please let me know how to resolve these issues as they are being very detrimental to our development.

Many thanks,

Hello Oliver,

Can you confirm what power supply you are using? You should be using a 12-V power supply with at least 7A. The bottom LED remains red when the power-up signals are not ready (specifically it checks the TPS65251RHAR buck regulator, 3.3V, 2.5V, and 1.8V lines). The green top LED is the heartbeat LED. If it's not booting up I don't think the controller ever boots.

Thanks,
Kyle

I am using a 12V power supply which can supply 1.5A, however I am using only the development board from the lighcrafter 4500 with nothing except the DMD connected (no LED, fan etc.). I will find a power supply that can supply more current; I have been using this supply for about a month before these problems started, could it really be the cause?

Also, on closer inspection the RED LED on the back of the board actually seems to have a red and green LED on solidly, sorry I didn't notice this before!

Thanks,
Oliver.

Hi Oliver,

It does seem odd that would be the case since it worked before but I would definitely try a more powerful supply since that is what those lights indicate (maybe you got lucky before).

And no worries about not noticing the green LED! The way it works is the green is always on but in essence you only see the red until that's turned off. It's easier to just control the red LED and when it's on it looks red and when it's off it's green. We just call it red (even though there is still a gree nhue) and green. It doesn't mean anything special though!

Thanks,
Kyle

Hi Kyle,

I got hold of a 12V supply that can supply 7A but the board still doesn't boot up properly (displaying the red LED on the back side).  Anything else you can suggest?

Thanks,

Oliver.

Hello Oliver,

Sorry to hear that. Did anything happen to the board in the past (over voltage, damaged part, etc.)? If the LED never goes green, it sounds like some of the power rails aren't being initialized properly. Perhaps one of the regulators was somehow damaged? Are you able to prove the voltages and see if any aren't what's expected.

Alternatively, if you are intermittently able to connect, try reflashing the default firmware to see if that's an issue. I will see if anyone else on my end has any debugging ideas. Otherwise you may need a new board unfortunately.

Thanks,
Kyle

Lastly, it may be possible the firmware is corrupt. You can try using the JTAG flash option to reflash it. See information at www.ti.com/.../dlpu017a.pdf

Thanks,
Kyle

Hi Kyle

Nothing physically happened to the board.  One day it was working, and the next it would not power on.  It could have been there as a voltage spike but it should be behind a surge protector.  I measure the voltages and let you know what I find.  Where would I find specs of what pads to measure?  Unfortunately I don't yet have the right cable for re-flashing the firmware over JTAG but I will get one and see if this helps.

Thanks,

Oliver.

Hello Oliver,

You can find the schematic and board layout at www.ti.com/.../dlp4500-c350ref. That should help you find what pads are easiest for you to probe. Let me know if anything isn't coming up to the correct voltage. Also let me know if the re-flashing works when you get a cable for JTAG.

Thanks,
Kyle

Hello Oliver,

I'm curious if you found any additional information?

Thanks,
Kyle

Hi Kyle,

Not yet I'm afriad, I haven't had a chance to continue with this.  Can you give me the part number of the JTAG cable that I should get in order to reprogram this?

Thanks,

Oliver.

Hi Kyle,

I haven't been able to check the voltages on the pads yet, but I have some other custom boards which use the DLPC350 and DLP4500. These are working fine (since we resolved the issue with USB_EN which you also helped with). However after some time of being able to upload firmware to these boards, the PC I am using started to show "Unable to read Flash Manufacturer ID" again. I switched to a different laptop and this worked for some time but has also started showing the same problem. Is there a solution for this yet?

Thanks,
Oliver.

Oliver,
In the LigtCrafter 4500 GUI there is hard coded 5.0 seconds wait state after entering the flash programming mode, this time is given for the DLPC350 controller to reconfigure from normal operating mode to flash programming mode.
Could you check if the PC is able to detect the USB enumerated after you initiate the download, basically when to initiate the flash download, you will see the USB device gets re-enumerated, if the PC is successfully detected then mostly likely the cause is 5.0 seconds wait time is not enough at the host side, you can try this option, let me know if it works
Just close the GUI and re-open, don't worry about GUI elements not updating, like f/w version # etc. go to flash download and start the process again. See you are able to initiate the download 2nd time.
Regards,
Sanjeev