troubles with backlight on skd204-634

volker

New member
everything on my display seems fine but backlight wont work :(
voltage is ok with 5V measured with my multimeter on J2 pin +5V LED and ground. but nothing.....

so connex looked like this

| | | | | | | J2
| | | | 5 5 G
| | | | V V N
| | | | D

any help would be great

THX

Volker
Looking for additional LCD resources? Check out our LCD blog for the latest developments in LCD technology.
 

CF Tech

Administrator
Probably we need to have you contact orders@crystalfontz.com to arrange an RMA. However here are some things you can check:



Please let me know the measurements on your display for these locations when the backlight is set to 100%. I measured a typical display and got these values:

+5v(LED) to GROUND: 5v
TPP to GROUND: 5v
TPG to GROUND: 5v
TPS to GROUND: 135mV
TPK to GROUND: 627mV
TPA to GROUND: 4.84v

Thanks.
 
USB LCD Displays - Graphic and Character LCDs with a Keypad

volker

New member
hmm, my values differs from yours

+5v(LED) to GROUND: 5.01v
TPP to GROUND: 5.01v
TPG to GROUND: 0v
TPS to GROUND: 0mV
TPK to GROUND: 0mV
TPA to GROUND: 5.01v

one other thing to mention, on your pic there are some parts on Q1, R10 and R12, which are empty on my print

Thanks

Volker
 

CF Tech

Administrator
That sounds like it would have to be a reflective display (SKD204634-SS) rather than a backlit one (SKD204634-SGLG).

Is there a backlight soldered into A & K?
 

volker

New member
no, there are no parts soldered into these contacts - i think i should contact your shipping department, as i it came out that these are the wrong parts shipped :(

Thanks for your help

Volker
 
Top