DS90UB925Q-Q1: Display NG occured， indicating link cable error

tao niu

Prodigy 120 points

Part Number: DS90UB925Q-Q1

Dear supporter,

our product has been using DS90UB925 and DS90UB926 for a long time and is always working well.

recently one NG sample is sent back for analyse.

the NG issue is No display, have backlight.

we checked the 926 pass/lock status, signals, registers, and the error indicate link status error.

we checked cable seems ok.

please help advise how to check further.

over 3 years ago

0 tao niu over 3 years ago

Prodigy 120 points

24# NG nanalyse.xlsx fpdlink 925.pdf fpdlink 926.pdf

0 Michael.Walker over 3 years ago in reply to tao niu

TI__Mastermind 19720 points

Have they done ABA swaps with the 925 board and the 926 board to see where which board the issue follows?

0 tao niu over 3 years ago in reply to Michael.Walker

Prodigy 120 points

Dear Michael,

we have found the cable isabnormal by changing lcd board, main board,cable one by one. the D- of cable is 15ohm by multimeter. and we have sent the cable for analyse.

the link status err indicate help.

just one concern, the link error code is all about short-circuit, not very same with our result.

and one question, when this error occurs, how dose 925 work? keep the status and no output, or try to detect again after some time, or try reset?

+1 Vijaya Ceekala over 3 years ago in reply to tao niu

TI__Intellectual 2930 points

Tao

926 will indicate Link and lock errors. Since it is a short (incorrect impedance), the data will not be received properly and will be detected as errors. Only the Llink error is detected and LOCK is dropped, the part will drop the LOCK and tries to re lock, If there is an issue, it will drop lock again and will keep trying to re lock

Thanks

Vijay

0 tao niu over 3 years ago in reply to Vijaya Ceekala

Prodigy 120 points

Dear macheal,

thank you for your explanation.

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DS90UB925Q-Q1: Display NG occured， indicating link cable error