Model CS- 40307 40 inch Mitsubishi TV will not turn on

Check its power regulator board. Check fuse. replace it as card basis, if found irrepairable.

if its not in the menu under audio output, see if theres a switch on the back around the audio output area that says external or internal

check first for the contact point of your control panel button maybe the tact switch is shoted specially when your always using remote control for function operation.second check power supply for leak capacitor or change in value,check also the photo coupler for leak test or change in actual.

try removing batteries from all remotes, a faulty remote may be turning your TV on/off. If it still does this, there is a power problem and you likely need a tech to look at it.

high volt or b volt going to high. reg circuit not working  normal to shut down need tech to repair.

I found this in another website... i hope this can help you. I'll try too...

Found this on the web, hope it helps.

Thank you for contacting Mitsubishi Digital Electronics America, Inc. We
are pleased to be able to assist our customers via our website. Here is the
information that you have requested:
TV Lock #8


Models:


Color Televisions
CS-20EX1, CS-20301, CS-26EX1, CS-26201, CS-26301, CS-2725R, CS-27EX1,
CS-27MX1, CS-27TX1, CS-27200, CS-27201, CS-27301, CK-27304, CK-27306,
CS-27401, CS-27403, CS-3135R, CK-3136R, CS-31AX1, CS-31FX1, CS-31MX1,
CK-31MX2, CS-31301, CK-31302, CS-3525R, CK-3526R, CK-3527R, CS-3535R,
CK-3536R, CS-35X7, CS-35AX1, CS-35FX1, CK-35FX2, CS-35MX1, CK-35MX2,
CK-35MX3, CS-35201, CS-35201A, CS-35203, CS-35205A, CS-35301, CS-35401,
CK-35402, CS-40FX1


Projection Televisions
VS-40VA2, VS-4517S, VS-45VA1, VS-45VA2, VS-4561, VS-4562, VS-5016R,
VS-5017S, VS-50VA1, VS-50VA2, VS-50VF1, VS-50VF2, VS-50VX2, VS-50VX3,
VS-5061, VS-5062, VS-6017R, VS-6026R, VS-60VA2, VS-60VF1, VS-60VF2,
VS-60VX2, VS-60VX3, VS-6061, VS-7017R


This system locks only the entire TV. The TV will display a screen that
will indicate "Parental Lock ... Now the lock is on" and request the
personal four digit code when the TV is powered on.


IMPORTANT> You must use the original remote control that came with the
TV to release the Parental Lock, you cannot use a remote
that came with a VCR, Audio System or from any other
manufacturer.


1. Depending on which remote came with your TV, press the button at
the top labeled TV,OR set the TV/VCR switch in the upper left
corner of the remote to the TV position. .


2. Press the button on the remote labeled POWER.
The TV will turn on and display an information
screen that indicates "Parental Lock ... Now the
lock is on" and ask for the four digit personal code.


3. Press the #9 and the QV buttons at the same time.
The TV will turn on.


4. Press the button labeled MENU.
The "TV Main Menu" will be displayed.


5. Press the ADJUST UP or DOWN button to move the arrow next to the
"Advanced Features" selection and then press ENTER.


The "Advanced Features" menu will appear and
indicate that the lock is ON.


6. Press the ADJUST button to move the arrow next to the "Parental
Lock" option, and then press ENTER.
The screen will change to indicate "Parental Lock
... Now the lock is on" and ask for the four digit
personal code.


7. Press the #9 and QV buttons at the same time.
The screen will return to the "Advanced Features"
menu and indicate that the lock is off.


8. Press the MENU button twice to return to normal viewing.


The original lock code has now been erased and the lock canceled.

Could be any number of things, none of them easy to diagnose. Unless your a TV repairman it's probably not worth fixing. It will cost tou more in repairs than a new TV.

A 22 code in Mitsubishi is a short circuit that is causing your set to go into protective shut down. Check the horizontal output and low voltage regulators for being shorted. Let me know if I can help you further, or if you need any additional info.