White Screen Issues

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minatorn
Posts: 4
Joined: Mon Mar 05, 2018 6:36 pm

White Screen Issues

Post by minatorn »

I bought a DSO138 and soldered all the parts to the board and now I am getting a white screen. I have listed below the voltage at each test point. Can anyone help me find the problem?
Input 9.38 AV- =-5.002 AV+ = 4.953
+3.3v = 3.262 +5v = 4.984 D1 = 0.148
R38(L)= 6.385 R38(R)= 8.370 R39 =-1.406
OSC = 1.927 TP22 = 3.263 R40 = 0.816
D2 = 9.380 V+ = 8.600 V- =-8.290
V1 = 0.053 V2 = 1.616 V3 =-2.857

I tried holding the soldering tip on each pin at J1 as well but that didn't help.
minatorn
Posts: 4
Joined: Mon Mar 05, 2018 6:36 pm

Re: White Screen Issues

Post by minatorn »

I forgot to upload pics of the board. Thanks in advance
Attachments
The board in question
The board in question
WhatsApp Image 2018-03-06 at 2.15.58 PM (1).jpeg
jye1
Posts: 1227
Joined: Wed Feb 20, 2013 4:58 pm

Re: White Screen Issues

Post by jye1 »

Did you see the LED blinked at power up? If you did that means MCU was running. The issue is likely caused by poor connections between MCU and LCD. It is suggested to check the soldering of pin-headers that connect the two boards. Re-solder each pin if necessary.
minatorn
Posts: 4
Joined: Mon Mar 05, 2018 6:36 pm

Re: White Screen Issues

Post by minatorn »

Yes the LED blinked twice at start up and when I tried test mode the LED blinks slowly. I will try re-soldering and update later.
minatorn
Posts: 4
Joined: Mon Mar 05, 2018 6:36 pm

Re: White Screen Issues

Post by minatorn »

I heated and reflowed the solder on each point at J1 and J3 on LCD board as well as J1 and J8 on Main board then did continuity tests on each pin of the both 40 pin headers and still can't find the problem.
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