hi there,
when i put the mainboard and the control board together with 4 screws, the controls did start to act funny.
-turning an encoder would sometimes not adjust any values, sometimes 3 or 4 at once, with values jumping all over the place.
-pressing buttons results in either no reaction or a white-screen or a screen with coloured lines (segments). the screen usually reboots and displays normally again.
- "Coloured lines (segments)" is a reinit command send from the pfm3 to the TFT when press MENU + INST- is pressed. So it's supposed to be clean again after 2 seconds.
- White screen is when the TFT receive corrupted data. You can then press MENU+INST- to reset it.
The pfm3 definitely receive bad key press information.
so i took the controlboard off again because i though one of the ribbon cable connections had become loose. holding the controlboard at a certain angle made it working normally again which made me think it was indeed a loose connection.
so i redid the solder on those connections, no change. ok i thought one of the cables has gone bad. replaced the ribbon cable, same behaviour. i measured with a multimeter from controlboard to mainboard and all points are connected.
Multimeter does not send high frequency signal.
The keys data is quite high frequency so it's possible there is some noise somewhere that prevent clean data transmission.
one thing i did notice when the boards arrived in the mail was that the mainboard was slightly bent, it had a slight curvature. putting the controlboard and the mainboard together may have forced that curvature to become flatter i guess and could maybe have broken some connections on the mainboard?
You only need the 5 pins connector + the right pin (top view) of the 8 pins header for the led. Look at the solder point on the PCB make sure they're clean.
Try to focus on that and maybe us a shorter ribbon cable.
are any of these symptoms familiar to you? can i somehow test if the mainboard is intact? any other ideas?
Yes, mainboards are slighly bent but that does not prevent them to working fine at all.
Broken connection (even one) would prevent any data to be transfered from the controlboard to the main board.
It's 100% a connection problem between the mainboard and the CB.
