|
|
Post by tibimakai on Aug 7, 2024 10:06:18 GMT -5
Maybe one of the HDMI ICs is bad?!
I had this issue in the past, and Todd helped me out in the past on how to diagnose this issue. None of the HDMI ICs are hot?
|
|
|
|
Post by serafis on Aug 7, 2024 23:45:08 GMT -5
That's what I'm thinking. The ICs get warm, but not hot. Since none of the HDMI inputs are working, I'm doubtful that it's Q8201 or Q8202 as I think they would both have to be bad for none of the inputs to work. Maybe Q8302, but the Net & USB inputs, and HDMI outputs work. I'll continue investigating but further help most appreciated.
|
|
|
|
Post by dobrykamil on Aug 9, 2024 4:45:50 GMT -5
Check all circuits firmware first.  |
|
|
|
Post by serafis on Aug 9, 2024 5:06:03 GMT -5
Unfortunately, as I mentioned, the front display is dead so I can't check firmware versions or diagnostics.
|
|
|
|
Post by ducklite on Aug 9, 2024 9:15:23 GMT -5
Hello serafis
does the unit poweron?, if yes then check the collector of Q7508 for -32V that is the filament voltage for the display
then check Q960 emitter for +3.3V this is the voltage that powers Q7501 pin57 the chip that controls the display (ML9208A-13GAZ)
if all of this is present then check pin3 of connector P701B this should be VP_con coming from the MCU to turn on the display (should be a logic high signal)
|
|
|
|
Post by serafis on Aug 10, 2024 0:15:31 GMT -5
Hi ducklite, yes, it does power on, and all functions work except front display and HDMI inputs. Q7508 collector reads -32.2V, Q960 emitter reads +3.32V. Pin 3 of P701B reads 2.9V.
|
|
|
|
Post by ducklite on Aug 12, 2024 19:00:48 GMT -5
did you check to see if 3.3V appears on pin 57 or 56 of the display IC ML9208 if it is there then
you might have a communication problem between the main processor and this chip
check p701B for FLDclock and FLDSDO and FLDSC with an oscilloscope to see the waveforms if they are correct.
if they are correct then the display should work.
|
|
|
|
Post by serafis on Aug 14, 2024 23:52:26 GMT -5
Thanks, yes, 3.3V is getting to the chip. I'll check the signals in a few days - bit busy at the moment with family stuff.
|
|
wolek
New Member
Posts: 8
|
Post by wolek on Aug 15, 2024 3:49:34 GMT -5
Measure resistance on 18 and 19 pins on hdmi inputs (to ground).
Graphics from net and usb inputs are fine on screen?
|
|
