Question about Mitsubishi VS-50705 50" Rear Projection Television

1 Answer

VZ7 chassis problem began with rolling picture and now protection kills power on process

The problem began with a rolling picture broken by several horizontal bars for half an hour and then the roll would cease and as long as the unit was left on, the picture would remain steady. Suspect vertical control circuit and convergence output amplifier STK's. No bad solder joints or broken trace are apparent. wiggle and tap tests yield no changes. Signal from pin 7 on IC802 is ringing with all sorts of overlapping signals. This had me believing the problem was a bad solder joint or crack in the trace...possibly bad amp. I wanted to test using manual circuit adjustment however the unit would not permit entry in to Service Adjustment Mode despite setting Direct key entry mode to "On". Since beginning to troubleshoot the signal and main boards, the unit suddenly ceased to complete powering on. Have STBY 12V on board and the fuses are intact....130V and 18V + HV is present for an instant and it would seem a protection circuit kills the process before it can complete.

Posted by on

  • Noel Rusnell
    Noel Rusnell Jul 30, 2008

    Hi, there, I should have specified more clearly: Self diag codes do not come up currently due to power not completely coming on Prior to failure to power "On" the self-diag code came up as 12--normal no errors and >>
    a. Option menu; press MENU 1270

    b. Service menu; press MENU 1257.
    <
    The most pressing issue currently is the failure to completely Power "On". Upon resolving this, I then need to address the rolling vertical blanking issue. I also do not have the service manual for this unit...only VS50507, VZ8 chassis, so I am winging this one unless you can provide one....perhaps trade?

    Unit will power on only long enough (500µs) upon pressing power button either with remote or on front panel to give 18V, 130V and then K903 de-energizes and kills HV and 16V, etc. before any diag codes can display. set clicks on, Horiz. Output energizes, flyback energizes, 1/2 second later K903 clicks off and set goes back to "off"


×

1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.

  • Master
  • 927 Answers

Good Day, NT-Services;

You may a vertical problem but I think it's not the vertical output amp. The problem should be in the voltages feed the vertical circuit. I have had cocern many times, so try this first:
1. VERTICAL ROLLING, VERTICAL BLANKING BAR LOCKING IN THE MIDDLE OF THE PICTURE, ALSO MAY HAVE HORIZONTAL PULLING OR TEARING. CHECK C2C52 10 UFD @ 50 V OFF THE BASE OF Q2C51 ON THE SIGNAL PCB. 2. CHECK C2P05 100 UFD 16 V OFF PIN 3 OF IC2P01 AND IC2P01 PART # 270P466020 (9-VOLT REGULATOR). BOTH ARE ON THE SIGNAL PCB.

Replace these caps no matter how they check.

2. Shuts down; may be intermittent, self-diagnosis ERROR 23 or 24. Check solder connections at connector "DY" on the yokes. Or/and check C411 2200 UFD 35V AND C412 10UFD 50V, both located on the main PCB.

3. Service adjustment codes:
a. Option menu; press MENU 1270
b. Service menu; press MENU 1257.

I hope this was helpful. Good day, big IRISH.

Posted on Jul 30, 2008

  • MICHAEL MULLINS Jul 31, 2008

    Good Day, NT-Services;
    If tries to turn and no error codes? Check IC700 pin 20 (AV off) for 0 VOLTS DC. If high, check for leaky D980 Part # 264P045040 on the main PCB.

    But I would suspect the caps previously mentioned and the vertical output IC. Try the caps and the IC first. ( CHECK THE CAPS AROUND THE 9 VOLT REGULATOR)

    Good Luck, big IRISH.









×

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
goodluck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

My RCA rdt325w unit has power but when I go to turn it on everything shuts off


If it tries I would first look at the power supply for damaged parts or puffed up caps.

All sets are protected with a shutdown circuit (some have several) and its job is to kill power if a short somewhere in the set.

Dec 12, 2012 | Televison & Video

1 Answer

I HAVE A MITSUBISHI VS-55705 AND THE CENTER OF THE SCREEN HAS A PERFECT PICTURE AND THE SIDES CURVE IN AND THE OP AND BOTTOM CURVE IN. wHAT IS THE PROBLEM?


THIS is a 1999 model VZ7 chassis and it uses two of the STK-392-110 CHIPS FOR CONVERGENCE.

If picture looks 3d or bowed with colors out of place or around letters etc, the chips need to be replaced.

I will attach photo of what the chips look like--one used here is the most popular one and used in many brands of sets.

Total parts cost for a pair will be under 20 dollars and repair takes about a hour.

If the picture or information I have provided told you something you did not know rate this solution as very helpful as I do this here for free.

SD TECH



b59d968.jpg


c0fd836.jpg

This is from a Hitachi but your set uses the same two black chips.

Aug 22, 2010 | Mitsubishi VS-55705 55" Rear Projection...

2 Answers

TV was working fine, moved to new home and the problem began. Picture rolls to the right, picture is fuzzy and will clear up somewhat at times. The picture will stop rolling at times also,but may be a half...


TV was working fine, moved to new home and the problem began. Picture rolls to the right, picture is fuzzy and will clear up somewhat at times. The picture will stop rolling at times also,but may be a half and half screen. Sound is fine, can you help me with this problem please.

Jun 23, 2010 | Sony KP-51HW40 51" Rear Projection...

2 Answers

I have a somsong hd tv and when i push the power button the tv want come on no picture. I hear a click sound every twenty seconds but no power seem to be getting to the picture tube tv mod# LNS4041DX


Based on your message, your TV has a bad high voltage section. Probably the HOT (Horizontal Output Transistor) failed or shorted and it either killed the high voltage or there's a current fluctuation; that is why the picture went, but there's a clicking sound. Then, when you turned it off or unplugged it the protection circuit remained active.

Once the high voltage fluctuates, that's the time the TV would create a clicking sound.

There's a 75% probability it will require a high voltage and horizontal deflection amplifier overhaul. The normal cost of that should be less than $200 if you take it in.

For this problem, I would suggest to contact a repair tech and have him take care of the problem.

Good luck!

Mar 02, 2010 | Televison & Video

1 Answer

Mitsubishi dlp 52525 garbled rolling picture. Picture just colored lines, rolling slowly. Sound fine, fairly new lamp.


You most likely have defective capacitors in your electrical chassis. It's best to send the entire chassis back to the manufacturer for total rebuilding. The cost is about $350 + labor, unless you can remove the chassis yourself.
Good luck.

Aug 09, 2009 | Mitsubishi WD-52525 52" Rear Projection...

1 Answer

Sony KP-51WS510, standby led blinks 5 times


It sound like you have a bad picture tube...check your 1k circuit for correct voltage and wave form.

Oct 03, 2008 | Sony KP-51WS510 51" Rear Projection...

1 Answer

Have no service manual--but suspect convergence output amps--now power issue


Its most likely the convergence ICs that are shutting the set down. Have you tried unplugging the convergence yokes to see if the set will then power up?

Jul 30, 2008 | Mitsubishi VS-50705 50" Rear Projection...

1 Answer

Mitsubishi VS-50705 convergence problem.


There should only be a couple of STKs, the R's are resistors, they STKs should cost under $20. This should be everything you are looking for. If you need anything else, let me know.

CHASSIS: VZ7
MODELS: VS-45605 / VS-50605 / VS-50705 / VS-55705 / VS-60705 / VS-70705

Ref # / Part # / Part Name & Description
IC8C01 267P141030 HIC- STK392-110
IC8C02 267P141030 HIC- STK392-110

Jun 05, 2008 | Mitsubishi VS-50705 50" Rear Projection...

Not finding what you are looking for?
Mitsubishi VS-50705 50" Rear Projection Television Logo

167 people viewed this question

Ask a Question

Usually answered in minutes!

Top Mitsubishi Televison & Video Experts

matt martin
matt martin

Level 3 Expert

1198 Answers

The Knight
The Knight

Level 3 Expert

69808 Answers

Donald DCruz
Donald DCruz

Level 3 Expert

17129 Answers

Are you a Mitsubishi Televison and Video Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...