Question about Philips Magnavox 51MP392H Rear Projection Television

1 Answer

Replaced ICs, now fuses are blowing

So I rearranged my room and the night I moved my TV, the convergance blew. Thinking it must have been due to moving and not knowing anything about televisions, I opened the back and tried to adjust the blue lamp, thinking it had come loose. It hadn't but what was loose was the screw that seals the fluid in the lamp. It had a few drops on the board, and when I touched the lamp, a few more dropped, and the fuse right under it blew. At this point, the TV would still turn on and off, I would hear the mechanical 'click' when powered on, but the secondary 'click' and the picture were no longer present, obviously because the fuse was toast.

So, I did some reading on here, changed the two ICs which was really easy, cleaned up any drops of that fluid, put it all back together, and now as soon as the plug touches the outlet, the fuse right next to the power cord immediately blows, and that other fuse blows in a less dramatic fashion. As a side note, there are 3 rectangle resistors 3301, 3302 and 3365 in the vicinity of the other fuse that are labeled 220R but measure 75 ohms, and the 6.8 ohm resistors around the ICs all measure 4.0-4.1 ohms.

My two questions are, 1, what could I check in the region of the power cord that could be causing this immediate fuse blow that was before not present? 2, should I be replacing all of the above-mentioned resistors,or am I doing something wrong in measuring them? It's strange that they're all measuring incorrectly at a consistent value.

I am a novice and really appreciate any help that anyone might be able to provide.

Posted by on

  • 3 more comments 
  • Dirt McGirt Oct 18, 2008

    I did not use a ground strap when replacing the ICs, but I am pretty sure I have the pins properly aligned.



    When you say I have direct short to ground, what does this mean? Should I be simply checking for an improper connection somewhere, or something else that is causing improper circuit path? Or am I likely seeing something physically failed?

  • Dirt McGirt Oct 18, 2008

    I actually do have a schematic, found here: http://www.mediafire.com/?ad1mtycjei3



    Wouldn't I need to have power to the set to test voltage? I can't get the plug into the wall without blowing the fuse.

  • Dirt McGirt Oct 18, 2008

    I just disconnected the connection between the board with the power cord and the board with the main power supply and plugged it back in. The fuse near the power cord didn't blow. I was also able to turn the tv on, heard a 'click', but obviously no picture or sound or anything because the two boards are disconnected. So I reconnected the power between the two boards and fuse 1300 near the power supply immediately blew. So I guess I should be checking in and around that area. From the manual:



    The Full Power supply is located on the Large Signal panel. The Raw B+ voltage from the Input panel is applied to the Full Power switching transistor, 7301, via Pins 6 and 8 of transformer 5300. This voltage is protected by Fuse 1300 and filtered by Choke 5330. The Standby line goes Low when the set is turned On. Transistor 7309 is turned Off, which turns 7300 On. This turns Relay 1305 On. Startup voltage is applied to Capacitor 2303 via resistor 3300. When 2303 charges to 14.5 volts, the undervoltage lockout of 7302 connected to Pin 1 is turned On. Drive is output on Pin 3 to the Switching FET, 7301. This drives 5300 to produce the Full power supply voltages.



    Transistor 7301 is right near where the fluid spill was. I don't know how to test a transistor, but would that be a good bet to replace?

  • Dirt McGirt Oct 20, 2008

    Bob,



    Thanks so much, I'm going to see if I can pick up an analog meter and follow the directions on that link you provided.

  • Dirt McGirt Nov 07, 2008

    I replaced 7301 with a transistor of relatively similar specs (since the original seems to be obsolete), and bingo, high definition television! Thanks so much for your help!

×

1 Answer

  • Level 2:

    An expert who has achieved level 2 by getting 100 points

    Hot-Shot:

    An expert who has answered 20 questions.

    Corporal:

    An expert that hasĀ over 10 points.

    Mayor:

    An expert whose answer gotĀ voted for 2 times.

  • Expert
  • 84 Answers

Did you have a ground strap to your wrist when replacing ic's and make shure you put the 1on the 1on th ic slot you have direct short to ground

Posted on Oct 18, 2008

×

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

I have a Samsung Rear Projection TV with an HDTV 1080i Monitor. I know the convergence is messed up because the blue would not move when I tried to adjust it on the menu. So, then I tried to make it


You will need to replace both convergence Ics and the pico fuses that blow when the Ics fail. You can get the replacement Ics and pico fuses from www.tvreairworld.com they also provide free tech support to help you install them

Oct 27, 2012 | Samsung HC-P4752W 47" Rear Projection...

3 Answers

I have an rca r52wh77 it is bowed in the top and bottom. it also is way off in convergence and i can not seem to get the crosshatches to come together. i have changed the fl123 part that was sent in my kit...


Does the kit have a pair of convergence ICs? That is what you will need to fix the convergence problem. The kit should also contain thermal grease(a white paste that should be applie to the ICs before you solder them) and resistors that may also need to be replaced. When a convergence IC blows its usually due to failed resistors.

May 26, 2011 | Televison & Video

1 Answer

P52921...TV was dead. I turned it off last night no power this morning small fuse was blown and I replaced it and cleaned very dusty lens and hard reset. Now TV is not showing on entire screen but has a...


Ur tv have a problems known as a convergence problems,it dead.The tv convergence board require the 2 STK convergence ICS and some or all it resistors,must be change to solved the convergence problems.The shop will cost u $300-350 for parts and labors.

Jun 28, 2010 | RCA P52921 52" Rear Projection Television

1 Answer

Replaced STK's, fuses ok, +/- 22 VDC ok, still can


did you checke the two 5amp IC protectors located on the G board? Those will usually blow when the original ICs fail.

Jun 12, 2009 | Sony KP-46WT510 46" Rear Projection HDTV

1 Answer

PT-47WX49E just shut off


maybe the convergence resistors? sometimes when the ics blow a resistor or a few blow

Jan 04, 2009 | Panasonic PT-47WX49 47" Rear Projection...

1 Answer

RCA model P61950


fl231 is the convergence fuse, and is soldered to the board in proximity of the convergence ICS, on RCA rear projection TVs.


If
fl231 has blown, TV usually does not turn on at al, if you get bowed picture, that means that the convergence ICs must be replaced.

The fuse is on the same board where you find convergence ICs, if the fuse had blown, or the pico fuses at the base of the STK convergence ics had blown, the STKs must be replaced.
There is need of purchasing the service manual to do the job.

The repair shuld be done by a technician.

This is the convergence IC, model may vary:

889c46e.jpg

Dec 13, 2008 | Televison & Video

1 Answer

Did you get an aswser on the IC's?


THe rca itc222 chasis has No convergence ics it uses a series of transistors to do the same. YOU replaced the Fl231 fuse and it blew. Did you resolder flyback connections. this is why the fuses blow. check out the article under the tips and tricks section written by me willtab ... see if this helps if not let me know .. i see alot of these at the shop ( i got one right now in front of me with the FL231 probelem LOL) if can let me know i give you help

Sep 15, 2008 | RCA R52WM24 52" HDTV Projection Television

1 Answer

Convergence repair problems.


alot of people make the mistake of putting two STK392-150 Ics in the Hitachi , and most times it will not work unless you change all the convergence resistors.. If youre going to upgrade hitachi to anything other than the stock ICs, it is recomended by Hitachi to use the STK394-160 ICs but then you have to change the ratings on the resistors. You can get the upgrade kit for your hitachi at the following link.
http://servicemanuals.vstore.ca/

Aug 29, 2008 | Hitachi 53UWX10B 53" Rear Projection...

1 Answer

Convergence fuse Toshiba rear projection tv


Wire jumpers need re-soldering....Locations 008,010,017 etc
on inside edge of signal board near convergence IC's.....research
my Toshiba " H " Model rear projection " blows fuses" solutions.
...................................T.

Jan 27, 2008 | Toshiba 55H70 55" Rear Projection...

1 Answer

Rear projection convergence out. replaced boards, blowing fuses


99% of these problems are due to either shorted pins or a missed pico fuse. The stk ic's are on the "D" board, attached to large heat sinks, When looking from the back you can see the heat sinks but the part's themselves will be pointing away from you and hard to see without removing the board, or using a mirror to look at the part numbers. The fuses are generally located under the fins of the heat sinks. There are several of them and vary by model. On the "G" board there will be two yellow pico fuses near the connector going to "D" board. These fuses provide power to the stk ic's you must check these as well.

Dec 16, 2007 | Sony KP-51WS500 51" Rear Projection...

Not finding what you are looking for?
Philips Magnavox 51MP392H Rear Projection Television Logo

81 people viewed this question

Ask a Question

Usually answered in minutes!

Top Philips Televison & Video Experts

The Knight
The Knight

Level 3 Expert

72670 Answers

matt martin
matt martin

Level 3 Expert

1207 Answers

Brian Sullivan
Brian Sullivan

Level 3 Expert

27725 Answers

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

Answer questions

Manuals & User Guides

Loading...