Hisense LCD4204EU LCD TV
Dead with a Bang Noise
> Replace chopper drive STRX6769, RE038 (10R) and RE032 (150R) in primary PSU.
Dead with a Bang Noise
> Replace chopper drive STRX6769, RE038 (10R) and RE032 (150R) in primary PSU.
Hisense
TLM3237D LCD TV
TV Power On then Shut Down
> Check the PSU board standby 5V STB normal and stable. But their POWER_ON signal is unstable, change in between 0~4.8V. Normally this POWER_ON signal is about 4.6V for this TV. So the problem was in main board or CPU section. Check their main board Voltage Regulator IC output voltages all normal and stable. Empty the U11 (24C32) EEPROM but not help. Testing the SCL & SDA line voltages it shows in between 0V~3.3V. Test the crystal Y2 (14.318MHz) it have 1.5V and another side is 1.7V. Use the ISP Programmer to program the correct version firmware into the main board flash memory U10 (PS25VF040). Power on the TV and the TV is working. After that, using remote control to control the TV function and their setting but it is hard to operate and slow motion to change function. Power off TV and then power it on again, the TV back to their original fault.
Replaced a new flash memory U10 (Cannot use the empty flash memory and it can’t start-up the TV, must using the ISP Programmer to copy their firmware into it) and solder it back to main board. Finally the problem solved.
TV Power On then Shut Down
> Check the PSU board standby 5V STB normal and stable. But their POWER_ON signal is unstable, change in between 0~4.8V. Normally this POWER_ON signal is about 4.6V for this TV. So the problem was in main board or CPU section. Check their main board Voltage Regulator IC output voltages all normal and stable. Empty the U11 (24C32) EEPROM but not help. Testing the SCL & SDA line voltages it shows in between 0V~3.3V. Test the crystal Y2 (14.318MHz) it have 1.5V and another side is 1.7V. Use the ISP Programmer to program the correct version firmware into the main board flash memory U10 (PS25VF040). Power on the TV and the TV is working. After that, using remote control to control the TV function and their setting but it is hard to operate and slow motion to change function. Power off TV and then power it on again, the TV back to their original fault.
Replaced a new flash memory U10 (Cannot use the empty flash memory and it can’t start-up the TV, must using the ISP Programmer to copy their firmware into it) and solder it back to main board. Finally the problem solved.
ChiMei V320B1-L06 LCD Panel with T-con board V320B1-C03
Screen fully with Vertical Color Lines
> This T-con board Vcc voltage is present. Check VDA voltage is 11.2V only. That’s mean their DC-DC circuit not working. Since their DC-DC IC AT1380A is control by the Timing Control chipset (CM2681A), when checking their switch on signal from CM2681A, it is no any signal from it. After that checking the CM2681A voltage supply IC N7 (2.5V voltage regulator IC) and found that has 0.9V volt output only instead of 2.5V. After replace this N7 IC , the screen is back to normal now.
Screen fully with Vertical Color Lines
> This T-con board Vcc voltage is present. Check VDA voltage is 11.2V only. That’s mean their DC-DC circuit not working. Since their DC-DC IC AT1380A is control by the Timing Control chipset (CM2681A), when checking their switch on signal from CM2681A, it is no any signal from it. After that checking the CM2681A voltage supply IC N7 (2.5V voltage regulator IC) and found that has 0.9V volt output only instead of 2.5V. After replace this N7 IC , the screen is back to normal now.
Hisense TLM3226 LCD TV (T-CON: ChiMei V320B1-C03)
No Display
The TV sound normal and it can control by the remote control. Backlight is
present but the screen no display and look like grey screen (because the
backlight was working).
> This LCD panel using ChiMei V320B1-C03 T-CON board. So first check their
Vcc input and other voltage values. Vcc input 5V ok, voltage regulator output
2.5V & 3.3V normal. When measuring the VDA, VGH & VGL voltage found all
not output 0V only.
It was shows that their DC-DC section is not working. After analysis the ir
DC-DC section, it is using the UP1 IC (AT1380A) as a DC-DC IC. The UP1 pin4,
on/off switch is control by the T-CON main chipset U3 (CM2681A-KQ) pin 63.
Usually when the TV on, T-CON board IC U3 (CM2681A-KQ) pin63 (PWRON) will
output a signal logic high (3.3V), through QP3 inverse the signal to logic low
and reach to UP1 pin4. After that, UP1, DC-DC section starting working and
generates VDA, VGH & VGL voltage outputs.
But for this T-con board, even the TV was power on, but their U3 (CM2681A-KQ)
pin 63 still is logic low 0V. Normally this U3 pin 63 will follow by TV power
on and off, their voltage range is between 0V~3.3V. Even disconnect the U3
pin63 with other corresponding components, this pin63 also not different still
0V. Suspect their U3 (CM2681A-KQ) damage, after replace U3 the TV was back to
normal now.
Hisense TLM40V68PK LCD TV
1) Pop up OSD Menu Randomly
2) Front panel buttons sometime no function
1) Pop up OSD Menu Randomly
2) Front panel buttons sometime no function
3) When TV in standby mode, can’t use the remote control to power on (start-up)
the TV.
4) Auto power on of power off the LCD TV.
> All these symptoms were causing by the ESD protection component call it as MLV (Multi-Layer Varistor). It is look like a small SMD diode and its function as an ESD protection & surge noise. How to testing it? Yes, this type of components normally they are using much in main board. So you can use the diode range to compare their values. If one of that MLV values different much or shorted, then you can direct remove it and power on the TV. If the problem solved, then you can find another MLV from a junk mainboard to replace it.
No wonder what brands or models of your LCD TV, if you’re facing the above LCDTV symptom and haven’t find out what was wrong, then you can try to check these MLV components inside their corresponding circuit lines. Some time on the signal input line, it is not one MLV defective, but maybe 2 or 3 units. For example, I had repaired an LCD TV with VGA port signal input no display problem. After checking their signal R, G, B, SDA & SCL lines got 3 MLVs shorted. Normally one MLV will using in one signal line, but this LCD TV VGA input signal got 3 MLV of them shorted and affect the VGA mode no display symptom.
Hisense TLM-3233D LCD TV
No Display but Blue Screen with Two Vertical White Bars
> When power on this lcd tv, the screen show no display but blue screen with two vertical white bars. The two vertical white bars will flash but no any content inside. The LCD TV can hear the sound and remote control to change channel properly. Try other video signals input like AV and PC also same results. Even try to call out the OSD menu also same problem too. Since the LCD TV cannot show the OSD menu and the TV got sound and change channel properly, so that the mainboard is normal. After observation this lcd tv, found that the problem could be in the T-CON board or LCD panel. Check LVDS and FPC cables, they are show as normal, then check the T-CON board voltages. All voltages in T-CON board are ok, so that i will suspect the T-CON board mainchip (N39) or their memory chip (N31) defective. I got the junk T-CON board with same part number, but their DC-DC chip was burnt. So the main chip and memory IC can be use. Because of the N39 (CM2681) have many pins and the memory IC N31 (24LC128) only have 8 pins, so that I choose to replace the N31 first. After replace the N31, I try to power on the TV, and it was show display perfectly.
Since this N31 is a memory IC, does that mean IC itself damage or just the firmware corrupt and caused this problem happen? To check it, I did use my programmer to copy the working memory IC firmware and write it into the new memory IC. Yes, the LCD TV working perfectly. The problem solved and it was causing by the firmware corrupted.
The T-CON board memory chip or their firmware corrupt also can cause the screen problem. So that we need to save their firmware and must prepare some junk boards of T-con board, main board and inverter board for future use.
4) Auto power on of power off the LCD TV.
> All these symptoms were causing by the ESD protection component call it as MLV (Multi-Layer Varistor). It is look like a small SMD diode and its function as an ESD protection & surge noise. How to testing it? Yes, this type of components normally they are using much in main board. So you can use the diode range to compare their values. If one of that MLV values different much or shorted, then you can direct remove it and power on the TV. If the problem solved, then you can find another MLV from a junk mainboard to replace it.
No wonder what brands or models of your LCD TV, if you’re facing the above LCDTV symptom and haven’t find out what was wrong, then you can try to check these MLV components inside their corresponding circuit lines. Some time on the signal input line, it is not one MLV defective, but maybe 2 or 3 units. For example, I had repaired an LCD TV with VGA port signal input no display problem. After checking their signal R, G, B, SDA & SCL lines got 3 MLVs shorted. Normally one MLV will using in one signal line, but this LCD TV VGA input signal got 3 MLV of them shorted and affect the VGA mode no display symptom.
Hisense TLM-3233D LCD TV
No Display but Blue Screen with Two Vertical White Bars
> When power on this lcd tv, the screen show no display but blue screen with two vertical white bars. The two vertical white bars will flash but no any content inside. The LCD TV can hear the sound and remote control to change channel properly. Try other video signals input like AV and PC also same results. Even try to call out the OSD menu also same problem too. Since the LCD TV cannot show the OSD menu and the TV got sound and change channel properly, so that the mainboard is normal. After observation this lcd tv, found that the problem could be in the T-CON board or LCD panel. Check LVDS and FPC cables, they are show as normal, then check the T-CON board voltages. All voltages in T-CON board are ok, so that i will suspect the T-CON board mainchip (N39) or their memory chip (N31) defective. I got the junk T-CON board with same part number, but their DC-DC chip was burnt. So the main chip and memory IC can be use. Because of the N39 (CM2681) have many pins and the memory IC N31 (24LC128) only have 8 pins, so that I choose to replace the N31 first. After replace the N31, I try to power on the TV, and it was show display perfectly.
Since this N31 is a memory IC, does that mean IC itself damage or just the firmware corrupt and caused this problem happen? To check it, I did use my programmer to copy the working memory IC firmware and write it into the new memory IC. Yes, the LCD TV working perfectly. The problem solved and it was causing by the firmware corrupted.
The T-CON board memory chip or their firmware corrupt also can cause the screen problem. So that we need to save their firmware and must prepare some junk boards of T-con board, main board and inverter board for future use.
Hisense TLM3201 LCD TV
No Display but sound and other function properly.
> This model of LCD has using two type of LCD panel. These LCD Panel are QD32HL01 and another one is QD32HL03.
For this LCD TV symptom, no display, the QD32HL01 LCD panel their T-CON board Q300 open circuit causing the TV no display. This Q300 function as an on/off switch for DC-DC section. Direct replace Q300 with FDN339AN and the problem solved.
For the LCD panel using QD32HL03, their T-CON board D304 (BAV99LT1) opened circuit and causing the TV no display. This D304 is using on the VGH circuit line. After replace D304 the TV problem solved.
Hisense TLM40V68P LCD TV (T-CON Board: V400H1-C01)
Display White Screen only.
The other function like sound and remote control are ok and working properly.
> This LCD TV panel take a bit long time to start-up the display. But the TV display white screen only. Since all other function normal, so the suspicion section is the T-con board.
Starts measuring this T-con board and found that their VGHP voltage is missing, 0V but other voltage testing points are normal. Normally this VGHP has about 19.5V. Power off the TV, using Multimeter ohm range to measure their VGHP point with GND and the values is 0 ohm! That’s mean the VGH P circuit line has component shorted. First check the circuit line filter caps, when remove that capacitor CP19, the VGHP circuit line ohm values are back to normal. After testing this CP19 and found it was shorted. After replace CP19 on the T-con board, the problem still remains the same! When checking the VGHP circuit line, it is still 0V. Forward to UP1 pin10, here can measure the 2.25V and 5VAC output. VAA testing point has about 13V, so to confirm that the DP5 is open circuit. After removed DP5 and using Multimeter to testing this component, double confirm that DP5 is opened circuit. After changed both components, the TV appear the display perfectly.
No Display but sound and other function properly.
> This model of LCD has using two type of LCD panel. These LCD Panel are QD32HL01 and another one is QD32HL03.
For this LCD TV symptom, no display, the QD32HL01 LCD panel their T-CON board Q300 open circuit causing the TV no display. This Q300 function as an on/off switch for DC-DC section. Direct replace Q300 with FDN339AN and the problem solved.
For the LCD panel using QD32HL03, their T-CON board D304 (BAV99LT1) opened circuit and causing the TV no display. This D304 is using on the VGH circuit line. After replace D304 the TV problem solved.
Hisense TLM40V68P LCD TV (T-CON Board: V400H1-C01)
Display White Screen only.
The other function like sound and remote control are ok and working properly.
> This LCD TV panel take a bit long time to start-up the display. But the TV display white screen only. Since all other function normal, so the suspicion section is the T-con board.
Starts measuring this T-con board and found that their VGHP voltage is missing, 0V but other voltage testing points are normal. Normally this VGHP has about 19.5V. Power off the TV, using Multimeter ohm range to measure their VGHP point with GND and the values is 0 ohm! That’s mean the VGH P circuit line has component shorted. First check the circuit line filter caps, when remove that capacitor CP19, the VGHP circuit line ohm values are back to normal. After testing this CP19 and found it was shorted. After replace CP19 on the T-con board, the problem still remains the same! When checking the VGHP circuit line, it is still 0V. Forward to UP1 pin10, here can measure the 2.25V and 5VAC output. VAA testing point has about 13V, so to confirm that the DP5 is open circuit. After removed DP5 and using Multimeter to testing this component, double confirm that DP5 is opened circuit. After changed both components, the TV appear the display perfectly.
Hisense
TLM4288 LCD TV
Screen fully of vertical color lines and then no display.
When power on the TV, it is ok but after half an hour, the screen was changed to vertical color lines. And it also appears some horizontal bar on the screen. Some time it can back to normal and change to vertical lines and then the TV no display. But their sound, backlight and the remote control, all function working properly.
> For this LCD TV symptom, so the suspicion parts will be the LVDS cable or their T-con board problem. This TV symptom was because of the mainboard LVDS signal are not match with timing control in the T-con board. First checking the LVDS cable both sides contact pins are clean and no any dirty on the pins. After that checking their cable continuity and it is ok. So the other part is the T-con board.
After testing T-con board all voltages normal and stable, so the problem should be in the LVDS connector and their signals processing section. Since this TV symptom was occur after half an hour, so it could be the components dry joints or heat sensitive. So after power on the TV, try to using a plastic rod to pressing the T-con. When the plastic rod pressing on the LVDS connector socket, the TV screen back to normal! So the culprit is the LVDS connector socket dry joints. After resolder the LVDS connector socket, the LCD TV is ok, even after burn test about 4 hours it’s still working properly.
Screen fully of vertical color lines and then no display.
When power on the TV, it is ok but after half an hour, the screen was changed to vertical color lines. And it also appears some horizontal bar on the screen. Some time it can back to normal and change to vertical lines and then the TV no display. But their sound, backlight and the remote control, all function working properly.
> For this LCD TV symptom, so the suspicion parts will be the LVDS cable or their T-con board problem. This TV symptom was because of the mainboard LVDS signal are not match with timing control in the T-con board. First checking the LVDS cable both sides contact pins are clean and no any dirty on the pins. After that checking their cable continuity and it is ok. So the other part is the T-con board.
After testing T-con board all voltages normal and stable, so the problem should be in the LVDS connector and their signals processing section. Since this TV symptom was occur after half an hour, so it could be the components dry joints or heat sensitive. So after power on the TV, try to using a plastic rod to pressing the T-con. When the plastic rod pressing on the LVDS connector socket, the TV screen back to normal! So the culprit is the LVDS connector socket dry joints. After resolder the LVDS connector socket, the LCD TV is ok, even after burn test about 4 hours it’s still working properly.
Hisense
LCD4204EU LCD TV
Dead after a Bang Noise.
> Replace chopper drive STRX6769, RE038 (10R) and RE032 (150R) in primary PSU.
Hisense TLM4788P LCD TV
Dead.
TV power on, testing the PSU secondary output voltage +12V, +5V_M & +24V all are = 0V no output. After that, testing the standby voltage +5V_S also same as 0V. That’s mean it was the standby voltage supply section malfunction.
Checking the NE521 (STR-A6351) pin 7 & 8 has 300V, but pin 3 is 0V. Normally this Power IC Vcc pin has about 15V.
> Check the corresponding components on Vcc line and found that RE523 was open and other parts are normal. Replaced a new RE523 resistor, the TV is OK.
Dead after a Bang Noise.
> Replace chopper drive STRX6769, RE038 (10R) and RE032 (150R) in primary PSU.
Hisense TLM4788P LCD TV
Dead.
TV power on, testing the PSU secondary output voltage +12V, +5V_M & +24V all are = 0V no output. After that, testing the standby voltage +5V_S also same as 0V. That’s mean it was the standby voltage supply section malfunction.
Checking the NE521 (STR-A6351) pin 7 & 8 has 300V, but pin 3 is 0V. Normally this Power IC Vcc pin has about 15V.
> Check the corresponding components on Vcc line and found that RE523 was open and other parts are normal. Replaced a new RE523 resistor, the TV is OK.
