Hello,
This is my first repair of new digital TV, I've only repaired mobile phones, notebooks etc. so far and some old TVs.
Symptoms: no picture; power on normally, joystick key and remote control works ok, tv is programmed with cable tv, changes channels, play sound normally, etc. TV has been working normally, but just picture disapearred one day.
TV has 4 boards:
- power supply
- mainboard
- some kind of OSD+Video mixer board (called URSA9 in service manual)
- T-con board.
Video signal goes like that: mainboard -> 51 pin LVDS cable -> URSA9 board with -> 2 LVDS cable (51 and 41 pin) -> T-con board. Mainboard ans URSA9 board have diagnostic "VX1 lock LED" which indicates that next board in chain has good signal connection and integrity receiving. Eg. URSA9 after receiving data calibrates and checks it, and if all is good, sends back to motherboard "LOCK" signal, and led on motherboard just lights on. Same situation with T-con -> URSA9, all lock LED lights on. So I assume video signal is properly going to T-con board.
Of course, power supply has been checked, for voltages not loaded and under load, all OK. Fuses on T-con OK. No difference with panel ribbons connected and unconnected. At further investigation, I've found that one of that two big Altera FPGAs, the left one on photo, isn't working. To be clearly isn't configuring. Left is cold, right gets as suspected warm in some time. Each FPGA has his own configuration memory chip, EPCQ256N. Normally FPGA downloads bitstream from it on power up, and configure itself withing 500ms . It can be watched, as DCLK and DATA pins of EPCQ for right FPGA are transmitting for this short time. Thought that maybe this EPCQ chip for left FPGA is broken or data corrupted, but after changing them in places, chip seems to be ok. it programs right fpga properly.
Clock generator driving FPGA has two outputs with good 25MHz signal, going to each FPGA.
I've got a clue if one of DCDC converter supplying power to left FPGA has slightly to big voltage, should be 1.15V, but outputs 1.23V. From what I've found in FPGA datasheet, it has build in POR circuit, that will not let to start configure itself until it has this supply voltage within its rating (1.15 +/- 30mV). Suspicious DCDC converter driver is marked 0A=1K X1P or OA=1K X1P. Can you help to decode it's name or/and find datasheet for it?
This is my first repair of new digital TV, I've only repaired mobile phones, notebooks etc. so far and some old TVs.
Symptoms: no picture; power on normally, joystick key and remote control works ok, tv is programmed with cable tv, changes channels, play sound normally, etc. TV has been working normally, but just picture disapearred one day.
TV has 4 boards:
- power supply
- mainboard
- some kind of OSD+Video mixer board (called URSA9 in service manual)
- T-con board.
Video signal goes like that: mainboard -> 51 pin LVDS cable -> URSA9 board with -> 2 LVDS cable (51 and 41 pin) -> T-con board. Mainboard ans URSA9 board have diagnostic "VX1 lock LED" which indicates that next board in chain has good signal connection and integrity receiving. Eg. URSA9 after receiving data calibrates and checks it, and if all is good, sends back to motherboard "LOCK" signal, and led on motherboard just lights on. Same situation with T-con -> URSA9, all lock LED lights on. So I assume video signal is properly going to T-con board.
Of course, power supply has been checked, for voltages not loaded and under load, all OK. Fuses on T-con OK. No difference with panel ribbons connected and unconnected. At further investigation, I've found that one of that two big Altera FPGAs, the left one on photo, isn't working. To be clearly isn't configuring. Left is cold, right gets as suspected warm in some time. Each FPGA has his own configuration memory chip, EPCQ256N. Normally FPGA downloads bitstream from it on power up, and configure itself withing 500ms . It can be watched, as DCLK and DATA pins of EPCQ for right FPGA are transmitting for this short time. Thought that maybe this EPCQ chip for left FPGA is broken or data corrupted, but after changing them in places, chip seems to be ok. it programs right fpga properly.
Clock generator driving FPGA has two outputs with good 25MHz signal, going to each FPGA.
I've got a clue if one of DCDC converter supplying power to left FPGA has slightly to big voltage, should be 1.15V, but outputs 1.23V. From what I've found in FPGA datasheet, it has build in POR circuit, that will not let to start configure itself until it has this supply voltage within its rating (1.15 +/- 30mV). Suspicious DCDC converter driver is marked 0A=1K X1P or OA=1K X1P. Can you help to decode it's name or/and find datasheet for it?
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