Re-Installation

Installation is the reverse of removal. The DM will slide down onto the four connectors at its base and there is a plastic vertical guide to ensure proper alignment of the board. Be careful not to bend the copper grounding springs that touch the connector end (rear) of the DM as it slides back into place. Carefully slide the DM shield back over the DM board and be careful not to snag the taller capacitors. Install the 6 screws that secure the DM in place. (Note that the two screws on the top of the DM shield are different from the other four). Plug the PWB-DEMOD card back in and ensure that its copper ground spring is touching the left edge of the DM shield.

Slowly slide the chassis back into the TV and be careful not to pinch any wires running to the front of the TV. The chassis should click as the release tabs lock into place. Secure the chassis with the long black screws. Reconnect all the wires you had removed and secure the excess slack back into the wire ties. Plug the USB and Firewire connectors back on the top of the DM and plug the cable from the front inputs back onto the top of the terminal board. Screw the grounding strap to the top of the doubler shield. Do not over tighten it as it is easy to break the threaded mounting plate on the shield. Install the DM rear cover and screws. Reconnect the coax antenna and digital audio cable back into the DM (if applicable).

Lastly, put the board slide back and remember that it could fall unless properly screwed in place. Double check all the connectors on the boards to be sure you haven't missed reconnecting anything. Install the rear cover of the TV and route the optional fan's power cable over the top of the rear cover to avoid pinching the cable.

Plug the TV back in and the front light should blink for about a minute as the DM boots. When the light has turned off, power up the TV and verify operation. If all goes well, your TV should boot in about one minute and there should be no more interference in the picture or OSD.

WS-65813 Advanced Troubleshooting

For those more technically inclined than most, you may enjoy the following. For the rest of you, IGNORE these checks.

1. CHECK FOR 12 VOLTS DC (AC-OFF DETECT) AT PIN 3 OF PC9A21 IF MISSING REPLACE PC9A21 PART # 268P058020 ON THE POWER PCB.


2. SHORT DETECT SHUTDOWN (PIN 13 OF IC700) CHECK FOR OPEN L902 PART # 351P155010 OFF Q904 C (15 V SUPPLY) ON THE MAIN PCB.


3. SHORT DETECT SHUTDOWN (PIN 13 OF IC700) CHECK FOR SHORTED D913 PART # 264P722010 AND OPEN Z901 PART # 283P039020 (Z905 AND Z900 M.


4. CHECK FOR BAD CAPACITORS IN DM MODULE.


5. CHECK FOR 10 VDC AT PIN 5 OF IC502 OF LOW, CHECK IC503 PART # 270P704010 ON THE MAIN PCB.


6. SUSPECT SHORTED WINDINGS OF T5A31 PART # 349P216010 ON THE MAIN PCB.


7. SHUTDOWN AT POWER WITH SELF DIAGNOSIS ERROR 2 2. CHECK FOR LEAKY C9A60 470 PF 1000 V PART # 154P400030, PARALLEL TO D9A57 ON THE POWER PCB 2. SHUTDOWN AT POWER WITH SELF DIAGNOSIS ERROR


8. CHECK FOR OPEN FUSES F9A04 AND F9A05 ON THE +24 AND -24 VOLT LINES. IF THE FUSES ARE OPEN THE CONVERGENCE OUTPUT CIRCUIT WOULD BE SUSPECT.


9. SHORTED HORIZONTAL OUTPUT TRANSISTOR.


10. COOLENT HAS LEAKED ON THE MAIN BOARD FROM THE CRT'S AND HAS DAMAGED THE MAIN BOARD BEYOND REPAIR.

Also, if the 24 volt B+ and or B- is missing from the convergence ICs, change both convergence ICs as well as the defective pico fuse in the power supply. This is most likely not a quicky type of repair. These are a few of my notes on this set from me and a few of my buds in the buisness. Good Luck and let us know how you made out with this set.

A Word of Caution

To all of you who may be attempting the capacitor fix on their Mitsubishi a word of caution. Modern circuit boards are easily damaged by static electricity. Tech's in the industry use grounding wrist straps when handling these boards. Simply walking across a room with the circuit board in your hand could damage it. Try to ground yourself to the metal chassis of the tv when touching circuits. Even though the TV is not plugged in it will equalize your electrical potential. Handle the circuit board carefully by the edges when taking it to your workbench. Try to ground yourself while soldering on the board. I bring this up after reading some posts that stated after changing out the caps they ended up with new or different problems. That's why you see new circuit boards shipped in the anti static special plastic bags.

This DM board communicates with the sets internal microprocessor. That's why if the set is working properly, and you first plug the set in, the light blinks and then stops blinking. When it stops blinking, that means the DM has booted up and is all in sync with the microprocessor and ready to go. If the set does not stop blinking, that is an indication that the DM has not booted up and communicated with the microprocessor. This is the basic explanation, as there is a lot more to it than this:

1. Could be poor solder connections, the power coming to the DM board from the main power supply could be bad.
2. The EEPROM could be bad
3. The power supply or sweep power supply could have bad connections or swollen capacitors.

The first thing to do is check all of the plugs, connectors, and connections to and around the DM board. Next would be to check for other large capacitors on other boards with swollen tops. The next thing would be to start checking power supply upon switch on. But, first do the diagnostic test as explained in the service manual. Maybe it will point you in the right direction.

If you have taken the time to follow these advance trouble shooting instructions and the Blinking Green Light continues to be a issue, a service tech may be required to complete the repair.

I hope that this Article has provided guidance and assisted in the repair of your Mitsubishi's "Blinking Green Light" issue.

Speed

Resources

Mitsubishi Service Manual: Mitsubishi Service Manual

If you require additional assistance or advice, feel free to send me a private message.

Contact information for Mitsubishi Customer Service:

MITSUBISHI DIGITAL ELECTRONICS AMERICA, INC. (MDEA)
9351 Jeronimo Rd.
Irvine, CA 92618
Mitsubishi Consumer Relations
800.332.2119
Fax: 949.609.4900

President & CEO (July 2008)
President & CEO
Ikuo Morisada
Mitsubishi Electronics
9351 Jeronimo Rd.
Irvine, CA 92618

E-mail: imorisada@mitsubishi-tv.com

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