DLP lightcrafter 6500 unable to switch to video mode

Yuting Dou

Hi,

My DLP lightcrafter 6500 has a problem similar to this one:

http://e2e.ti.com/support/dlp__mems_micro-electro-mechanical_systems/advanced_light_control/f/94/t/527689#pi239031350filter=all&pi239031350scroll=false

But I don't see a follow up on solving the probem from the author. The DMD was doing well and the next second when I sent it some patterns it showed nothing on the screen. The LEDs shows that the boards are fine. I suspect it is the cable's issue. I downloaded all the reference design mentioned in the previous post, but could anyone tell me which document should I look at and how should I probe the SCP_DO, SCP_DI, and SCP_ENZ? How could you tell if the golden cable is broken?

Any answer would be appreciated.

Best,

Yuting

over 9 years ago

0 Paul Goedeke over 9 years ago

TI__Mastermind 30600 points

Hi Yuting,

The best way to tell if the flex cable is broken is to carefully inspect it for any damage. Please confirm as well that you have not bent the cable any tighter than a 25.4mm radius. If you have, the cable is very likely damaged.

Have you modified your board at all? Can you send a picture of your set-up?

Are there any errors shown on the left hand side of the GUI?

Thanks,
Paul

0 Yuting Dou over 9 years ago in reply to Paul Goedeke

Prodigy 65 points

Hi Paul,

Thank you for the reply. I didn't bent the cable very tightly before. The board was mounted on a 45 deg platform, so I think the cable might have suffered from some sheer stress. I didn't modify my board.

On the GUI everything looks normal except for in "system controls", it stays on the "standby mode". I just updated the v2.0.0 firmware, and it didn't change anything.

Thanks,
Yuting

0 Yuting Dou over 9 years ago

Prodigy 65 points

May I ask in which document can I find these SCP_DO, SCP_DI, and SCP_ENZ lines? And also can I just use a multi-meter to probe them while the power is on? Do these signal and power line share the same GND?

0 Paul Goedeke over 9 years ago in reply to Yuting Dou

TI__Mastermind 30600 points

Those lines should be in the schematics of the reference design: www.ti.com/.../swlicexportcontrol.tsp

You'll need an oscilloscope to probe those lines - a DMM isn't fast enough. They do share the same ground.

Paul

0 Paul Goedeke over 9 years ago in reply to Paul Goedeke

TI__Mastermind 30600 points

There will either be test points or resistors that you'll be able to probe with the oscilloscope to make sure the signals are being properly sent. More than likely your failure is the flex cable. If you'd like to order a new one, see question 6 here: e2e.ti.com/.../3433.dlp-lightcraftertm-65009000

0 Yuting Dou over 9 years ago in reply to Paul Goedeke

Prodigy 65 points

Hi Paul,

Thank you for your reply. I probed some electrodes on the two ends of the cable according to the TI_Flex_Cable_Schematic.pdf. Unfortunately some of them are not connected. I think there might be some broken wires inside the cable, even though we couldn't tell form outside. The cable can still power up the DMD board (the mirrors are heating up, etc.) but it no longer transfers signal. Like you said I might need to buy a new cable.

Thanks,
Yuting

0 Paul Goedeke over 9 years ago in reply to Yuting Dou

TI__Mastermind 30600 points

Yuting,

Something else you could try is to take the flex cable off the EVM and probe the ends with your DMM for continuity. The process of removing and then carefully re-seating the flex could help as well.

Thanks,
Paul

0 Yuting Dou over 9 years ago in reply to Paul Goedeke

Prodigy 65 points

Paul,

Thank you. That's what I did. I selected some electrodes on the ends like J1 A01 to J2 B01 and they are connected. But electrodes like J1 B06 to J2 A06 are disconnected. I used a digital multimeter to do the tests.

Thanks,
Yuting

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DLP lightcrafter 6500 unable to switch to video mode