SHARP LCD AV MONITOR LC28HM2 Power and Display unit Circuit Diagram
LC32DH65E LC37DH65E LC46DH65E LC52DH65E LC32DH66E LC37DH66E LC46DH66E LC52DH66E LC32DH77E LC42DH77E LC46DH77E LC52DH77E LC32DH77EB _ Troubleshooting
SYMPTOM: Dead or stuck in standby. All Sharp LCD TV sets have a Lamp Error
detection circuit which will return the LCD TV to stand-by if a fault is
detected, the fault is logged by the lamp error counter which will render the
LCD TV inoperative if it the error count reaches 5. To enable fault finding the
lamp error detection circuit is ignored when service mode is activated. Service
mode activation is detailed in the relevant service manual. After the fault has
been diagnosed and repaired the lamp error counter must be reset to “0” before
normal functionality is restored, again this is detailed in the relevant
service manual.
CAUSE: Possible causes of this symptom are:
CAUSE: Possible causes of this symptom are:
> Inverter circuit failure (switching transistors)
> Lamp failure (no or low
output)
> Poor or loose connectors, fuse holders (lamps or inverter board).
> Dry joints (power supply or inverter board).
> Trapped or chaffed cables to lamps.
> Power feed to lamp inverter circuit.
> Fault in error detection circuit
ACTION : Repair the unit as necessary and reset the lamp counter.
ACTION : Repair the unit as necessary and reset the lamp counter.
LC32DH65E LC37DH65E LC46DH65E LC52DH65E LC32DH66E
LC37DH66E LC46DH66E LC52DH66E LC32DH77E LC42DH77E LC46DH77E LC52DH77E LC32DH77EB
SYMPTOM: Takes in excess of 1 minute to switch On. No power and lamp error indication.
CAUSE: Errors on the 3.3v + D supply line.
ACTION: Locate C9668 on the under B-side of the Main PWB using figures 1 to 4 and replace.
REF NO DESCRIPTION PART NUMBER PRICE CODE
C9668 Capacitor 68 nF SMD VCKYCZ1AB683KY AB
CAUSE: Errors on the 3.3v + D supply line.
ACTION: Locate C9668 on the under B-side of the Main PWB using figures 1 to 4 and replace.
REF NO DESCRIPTION PART NUMBER PRICE CODE
C9668 Capacitor 68 nF SMD VCKYCZ1AB683KY AB
MODELS LC32D65E LC32DH66E LC37D65E
LC37DH66E LC46D65E LC46DH66E LC52D65E LC52DH66E
SYMPTOM: Green LED and No backlights.
CAUSE: Corrupted firmware.
ACTION: Install the latest firmware as detailed in the service manual using a USB stick, then enter the service mode and ensure the necessary adjustments for screen size etc are reset.
SYMPTOM: Green LED and No backlights.
CAUSE: Corrupted firmware.
ACTION: Install the latest firmware as detailed in the service manual using a USB stick, then enter the service mode and ensure the necessary adjustments for screen size etc are reset.
MODELS LCxxD44E LCxxD65E LCxxDH65E
LCxxDH77E
SYMPTOM: Unit enters trip mode. Green LED illuminates then the set goes to standby a few seconds later.
CAUSE: Lamp error counter reaching maximum limit. If the lamp counter is reset, the set will work until the limit is reached again.
ACTION: It has been found that any of the lamps within the LCD panel may not be fitted correctly and cause’s the lamp to function intermittently and an error is then produced. Carefully and in a clean environment remove the LCD panel from the cabinet fascia and then remove the LCD glass sheet and diffuser to expose the backlights. Look at the lamp connections within the back panel and ensure the lamp metal contacts are correctly located.
SYMPTOM: Unit enters trip mode. Green LED illuminates then the set goes to standby a few seconds later.
CAUSE: Lamp error counter reaching maximum limit. If the lamp counter is reset, the set will work until the limit is reached again.
ACTION: It has been found that any of the lamps within the LCD panel may not be fitted correctly and cause’s the lamp to function intermittently and an error is then produced. Carefully and in a clean environment remove the LCD panel from the cabinet fascia and then remove the LCD glass sheet and diffuser to expose the backlights. Look at the lamp connections within the back panel and ensure the lamp metal contacts are correctly located.
The Lamp contact in Figure 1 is only sitting on the edge of the end
clamp; Figure 2 shows a correctly fitted lamp.
SHARP LC28HM2 Power unit schematic
Display amp unit schematic
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