Hd50lpw175x7 Hey, It's not the power board. Replaced power board with new one still has the same symptoms. Do you think it could be the ballast? How can I check my old ballast to know for sure? Joyce

Hi W Bloom,


First of all, thank you for contacting Fixya.com regarding your TV problem.


My first advice is to do system reset by pressing the "Power" button key at the front panel and hold it for 10 secs.


Please check also if you can access the "Error Code Log" by pressing the "Menu" "3" "5" "6" "4" in sequence before the unit gone to shutdown.


You've mentioned that the bulb has been replaced just last Sept and now it won't come on. The lamp can't be test using the multimeter but you can make a visual inspection to determine its condition. Most of the faulty lamp has an obvious burnt mark. There's a possibility that the symptoms is caused by busted lamp but in your case, if it is a genuine lamp replacement, then high chance that the fault is not the bulb.


You need to check the ballast board but not the high voltage output of it feeding the lamp. No voltage coming out from the power supply board to the ballast board can produced the same symptoms. You have to check the this voltage at connector CJ1, you must get 325V to 340V. Check also the lamp enable at connector CJ3(pin 4) you must get a low voltage upon turning on the set to confirmed that the mainboard giving a signal.


If there's no voltage at CJ1, then the fault is on the power supply board.

If the readings are normal, and still the ballast won't ignite (you can hear a slight snap sound when the ballast board trying to ignite), then you have to replaced it.


Click the link below to order online.


http://bigtvsale.blogge.rs/2011/05/31/discount-replacement-mitsubishi-oem-pwb-ballast-938p178010/


http://www.shopjimmy.com/mitsubishi-938p178010-lamp-ballast.htm


Please let me know if you need further assistance.


Good luck and take care!


Kind Regards,


Mjsazon

hi good day
before you come up that the main board was the problem lets verify first to narrow down where the problem came from. now as you said you have been tried to put a backlight just to know if their is a problem with the backlight but still you have black screen so which mean the inverter ballast is possibly good as will as the backlight. ok here is on how will you trace the main cause you need to turn on the tv unit then check if their is a INV_ON voltage around 3.3V coming from processor going to inverter ballast, now if do not have voltage turn off the unit then disconnect the connector going to the ballast board and turn on the unit check again the INV_ON if still no voltage come out you have bad processor from the main board. now if the case is the INV_ON voltage is present their is a shorted component at the ballast board that is why the screen is going black after you turn on. if their is an error detected the main board will cut off. hope this will help you thanks for consulting through fixya god bless.

hey there it sounds like the problem is coming from your ballast board, the ballast board is the power source to the lamp. with time this part starts to wear out and get weak your old lamp is already burning out there for it does not need that much voltage to turn on but the new lamp has not been worn out or used there for it needs the ballast to be working at 100%

hope this solution helps

U hear alot of clickings,few mins tv is on?The board call the Ballast board is dead.This Ballast board help to ignite the projection lamp.

This tv have a colors wheel.U hear grinding noises? Picture flickers black&white.That the indication the colors wheel is dead,need a new colors.U have Lamp LED front Lit up or flashes?That mean the projection lamp life is over,require a new projection lamp.U hear alots of clicking sound?That mean the Ballast board is dead,this board help to ignite the projection lamp.

It depends on how much the new ballast will cots, new or used that is another question. Do you see any burnt parts, bad capacitors in the ballast board?

make sure all cables . connectors are seated at their right place.make sure lamp is secure and closing lamp switch .lamp door switches are closed .

The ballast board controls the lamp. The lamp socket wires connect directly to this board, so locating it isn't difficult. Replacement parts can be had here : www.shopjimmy.com TV Parts Universal TV Stands DLP Chips ShopJimmy

it should either be secured with screws or plastic clips that need to be pressed in to release the board

The power supply is what provides all the standbye voltages that get routed to the various other boards. The capacitors have to be unsolderd and the replacements solderd in.