SOURCE: Mitsubishi model No. WS-55807 - In need of schematic please
I have a WS-55807 that will not power up. When the power button is pressed I hear a click from the back of the set, the timer light comes on and 3 seconds later I hear a click from the back of the set, and the timer light goes off. I started checking power to the unit with a voltmeter. For those intersted I have attached scematics: I verified that the PCB main fuse is good and there is 120V at point PT.
From what I can tell is happening, the power button is pressed and the P-ON transistor is given a signal to conduct which causes K9A50 to close. K9A50 opens after about 3 seconds.
I am looking for other troubleshootinng steps. I have checked fuses F9A01 and F9A06, both are good. What are some other things to check for? Where does the P-ON signal come from?
In the switched supplies regulator circuitry I found fuses F9A04 and F9A05 blown (denoted by red lines thru components). I jumpered around F9A04 and F9A05 with good 5A fuses and the TV powered on. However when the set was plugged into an outlet there was a huge power draw (sparks from the outlet).
After jumpering around the blown fuses, the TV stayed powered on for about 30 sec and then powered down. I pressed the power button a few more times and the same result. The TV stayed on for only 30 sec.
I pulled the middle PCB whichs holds these circuits and I found the
D9A60 diode open and IC8C02, one of the convergence IC's fried. I don't know if these were like this before or after jumpering.
I replaced all bad components and I am back to square one. The K9A50 relay stays closed for 3 sec and the set does not power on any further.
Comment by TV_ITGuy, posted on Dec 19, 2007
Thanks for the advice ctf1800. I have read several posts that speak of the DM unit. I have looked in the back of my set and the DM unit is not in the location shown in the pictures.
As I hope you can see in this picture, there is no DM unit to the far left, just open space. Also the service manual for the V17 chasiss does not speak of a DM module.
I checked the reisitors on the output of IC8C02 which are a couple of 3.9 ohm resistors in parallel. When I test them I get approximately 1.9 ohms, which is what it should be with them being in parallel.
Please let me know if I am off base on any of this. Thanks
Comment by TV_ITGuy, posted on Dec 19, 2007
Also, I have replaced both of the Convergence IC's when I replaced the fuses and diode.
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Best Solution
posted on Dec 19, 2007
ctf1800
Rank: Wiz
Rating: 84%, 2716 votes
first off you should replace both convergance IC and check the resisters coming off the output if any of the resisters are bad it will trash the ic on trying to power up.
i would also replace the caps in the DM section
http://www.jeremyburns.com/Mitsubishi-Green-Blinking-Light-Fix.pdf
http://chrisandnat.com/projects/blinkingtv/blink.htm
Comment by ctf1800, posted on Dec 20, 2007
there are six fusible return resistors ranging from 1.5, 1.8, 2.2, 2.7, 3.3, 3.9 Ohms. I would lift one side of the resister out.
check for any caps that look puffy and check the horz. out put transistor.
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SOURCE: Mitsubishi WS-55807 TV won't turn on
I have the same problam,I got this tv for free and i am trying to find out what is wrong with is so i can fix it.has any of yall got yalls fix if so what did you do to get it to work.
Thanks
Dustin
SOURCE: Mitsubishi 55 inch Digital TV WS-55807
Good Day; This model is equipped with a self-diagnosis feature to help with diagnosis of shutdown problems. To activate this turn the unit on let it shutdown then press the input/device and menu buttons on the front panel simultaneously and hold them in for 5 seconds after 5 seconds the power LED on the front panel will blink a two digit sequence. This will be one set of blinks a short pause then another set of blinks, this will repeat 5 times. 1 - 2 = no error detected 2 - 1 = X-ray protect (high voltage or beam current) 2 - 2 = Short protect (short protect monitors low voltage supplies) 2 - 3 = Deflection protect (this could be loss of vertical or horizontal deflection) 2 - 4 = Vertical protect (usually loss of vertical from the source) 1. SELF- DIAGNOSIS INDICATE X-RAY. CHECK FOR A SHORTED IC5A03 PART # 270P704010 AND AN OPEN R5A73 82K ¼ WATT OFF PIN 2 OF IC5A02 ON THE MAIN PCB. 2. SELF DIAGNOSIS ERROR INDICATES SHORT PROTECT. CHECK FOR OPEN FUSES F9A04 AND F9A05 PART # 283P043090 ON THE +24 AND -24 VOLT LINES. IF THE FUSES ARE OPEN THE CONVERGENCE OUTPUT CIRCUIT WOULD BE SUSPECT. 3. SELF-DIAGNOSIS INDICATES SHORT PROTECT. CHECK FOR A SHORTED IC4B01 PART # 270P261020 (VERTICAL OUTPUT) LOADING 24-VOLT SUPPLY LINE. LOCATED ON THE MAIN PCB. Good Luck, big IRISH.
SOURCE: Won't come on
The power board has failed and will need to be repaired or replaced. you can remove this board and, replace individual parts and save a lot of money. You will be inspecting for swollen capacitors and resistors. also, look for discolorations on the board itself.
SOURCE: High Definition--WS-55807
IF the MITS has 3 component inputs blue red yellow RCA jacks on the back then yes at 480 or 720p, you'll need to attach 2 audio cables for sound. If it has a HDMI input then absolutely.
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