Question about Projection Televisions

1 Answer

Panasonic TC-25V50A TV circuit schematic needed to try and fault find. Set completely dead except for red led signifying power on. Power fuse OK. No blown out capacitors or resistors apparent. Can you help? Thanks, John Bates

Posted by on

1 Answer

  • Level 1:

    An expert who has achieved level 1.

  • Contributor
  • 1 Answer

Success! After finding nothing with a visual check I dropped the set about 3inches and all is well. Must be a mechanical connection problem. Probably a dry joint, will resolder if it happens again. John

Posted on Nov 30, 2008

Add Your Answer

Uploading: 0%

my-video-file.mp4

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

×

Loading...
Loading...

Related Questions:

3 Answers

1.Dead on switch but red power LED comes on. Previous to this intermittent fault with flyback lines then red screen then white screen and loss of sound.


Flyback transformer is very likely bad. Also the most common in these sets as well. The transformer provides and regulates the power. There should be a label on your set that has the DC voltage output rating. You can use a voltmeter and measure the rating your flyback is putting out and see if they are the same.

Feb 16, 2010 | Projection Televisions

Tip

RCA, CRT Projection TV, ITC222 chassis Faults - models D52W.., D40W.., D56W..,...


RCA, CRT Projection TV, ITC222 chassis Faults - models D52W.., D40W.., D56W.., D61W..
· Symptom: No Convergence, Picture is bowed and distorted, colors don’t align.
The Fuse for the convergence power supply has blown
You'll also notice that the convergence settings have disappeared from the on screen menu. The fuse likely blew because of a fault on the convergence board. If you've never done soldering or dismantled a TV before this is probably not the best place to start. The back cover needs to be removed and the fuse (see picture) identified, the deflection/power supply board needs to be unplugged (label or mark all connectors beforehand) and flipped over and the fuse checked/replaced. You need a soldering iron and solder ****** or solder wick and a multi-meter to check the fuse. If you want to tackle it yourself see attached image for reference or get a quote from a repair shop (approx $200-$300 Total) the convergence board may also need repair.



  • Symptom: Dead Set - TV Tries to Start or intermittent dead.

The set could be in shut down mode due to a fault detected in the power supply, vertical or horizontal deflection circuits.
The common problems with this chassis that will cause a dead set or intermittent dead set symptom are, bad power supply capacitors, bad flyback, bad HV cap in horizontal output circuit and cold solders (on opposite side of board) especially under the flyback area. To gain access to replace any of these parts the back cover needs to be removed and the deflection/power supply board needs to be unplugged (label or mark all connectors beforehand) and flipped over.
These are only the most common problems and it could be any number of other faults.
If you have electronic (TV) repair experience check the items mentioned (see picture), otherwise it's best to seek a qualified RCA tech for an estimate/service call.

· Symptom: Erratic operation of set – turns off by self, the volume or channel changes by self or on screen menu appears intermittently.

Switches on the front panel assembly (FPA) problem.
What happens with this model is the FPA switches (one or more) start to conduct just as if someone was pressing the buttons. This in effect locks up the system control or causes it to initiate erratic commands.
The way to determine if the FPA is bad is to remove it by unplugging from set. This requires front panel disassembly.
Note: The remote will still work with the FPA removed so the set can be tested.

Hope this helped, johnnydiode, Fixya.

bcbda82.jpg

on Dec 08, 2009 | Projection Televisions

2 Answers

No power


Ypu will first have to check the horizontal output transistor and make sure it is not shorted. The voltage for the horizontal output transistor comes from pin14 of the SMPS transformer. Then it goes through the coil,L815, then to the diode for B+,D825. Then the B+ goes through coil L816. Be sure after D825 you check the capacitor, C830, as this is a very common fault with this set. Then the B+ flows through L817, then through two One ohm resistors, R857 and R858 to pin8 on the flyback transformer. If you get B+ on pin 8 of the Fly, and none on the horizontal output transistor, the fly is open and is bad. I have a schematic that is very close to this set but not an exact one, but most of these sets are about the same, and if you know anything about Panasonic TV sets, you should be able to repair them with a schematic from another set. BTW, this Horizontal and fly circuit is on the D board. If you wish to have a copy of the service manual for a set close to yours, I will send you a copy. If you follow these instructions, you should be able to find the fault with this TV set. If the SMPS is not working, you will not get any voltage also on the HOT. Good Luck

Jul 02, 2007 | Panasonic PT-47WX49 47" Rear Projection...

1 Answer

DP23 LED not lit on deflection board no picture on tv


Good Day, Gil;
Your problem is in deflection circuit (115+v) check these: FP05, DP15, Q777, QH01, TH01, T701, etc. BUT suspect C707 1k pfd, 2kv, and check all the pico fuses (brown) 2" to the right of cap. Good Luck, big IRISH.

Jul 19, 2008 | Hitachi 53UWX10B 53" Rear Projection...

3 Answers

Mitsubishi WS48511 TV will not power on completely.


have you checked the pico fuses on the bottom side of the PC board? They are small ceramic fuses soldered directly to the runners.They have been known to blow and your set will not power up. Hope this helps, if you need anything further let me know. Also sometimes the 1000uf caps don't show any signs of swelling but can still be bad.

Jan 23, 2008 | Mitsubishi WS48511 48" Rear Projection...

7 Answers

Hitachi 60"(60sbx78b) Will not power on, fuse still good.


Matt, Hitachi`s have a series of green LED`s and one red LED on the main board, un-plug the tv for 30 seconds and then with the back cover removed plug the set back in and watch the led`s while someone else turns on the set, usually the led`s will temporarily light then one or more will immediately go out and then the rest will slowly go out and the red one will then start blinking, each led is a power supply indicator, 130 volt, 12 volt, 5 volt etcetera, find out which one(s) going out first and get back to me, BMW Rider

Jan 04, 2008 | Hitachi 60SBX78B 60" Rear Projection...

4 Answers

Philips 51PP9200D/37 not comming on


Check the site www.TvRepairKits.com. They have put together a couple of kits to fix the chirping set/dead set condition. If you don't see your model listed send them and email and they will build a parts kit for you.

Dec 11, 2007 | Philips 51PP9200D Television

1 Answer

Power button flashing red


stk convergence packs may haqve failed in the dead short mode stk392-110 removing them from circuit may allow the set to turn on again good possibility do you know how to solder?

Dec 07, 2006 | Panasonic PT-53X54 53" Rear Projection...

1 Answer

TV has power but no picture.


If you know how to read a schematic diagram and have the proper tools then you should be able to fix the set. The first thing and most common for your symptom is a bad regulator IC in the main power supply It will be standind up on a heat sink and start with STR and have 4 numbers after it. Now it could also be a problem in the sweep circuit but not to many faklures there. I have seen once that a blow audio output IC shorting out cause the entire set to shut down and it did take out the regulator IC with it Too. A shop repair for a set like this can run around 250 all the way up to 500 bucks depending on what the fault is. Hope this helps ya. Good Luck

Jun 03, 2006 | Toshiba 42H83 42" Rear Projection...

Not finding what you are looking for?
Projection Televisions Logo

Related Topics:

61 people viewed this question

Ask a Question

Usually answered in minutes!

Top Projection Televisions Experts

Jaime Hernandez

Level 3 Expert

2267 Answers

matt martin
matt martin

Level 3 Expert

1191 Answers

yadayada
yadayada

Level 3 Expert

60867 Answers

Are you a Projection Television Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...