Question about RCA P52960 52" Rear Projection Television

1 Answer

SCR mounted on heat sink on board marked 15888430 blown, fuse blown

I can't find this part number on any parts web sites SCR marked 019701 on the board next to the component. Any suggestions about board or component availability or potential cause of failure?

Posted by on

  • pksent Aug 22, 2008

    Unfortunatly, the face of the diode cracked when it blew and destroyed the face. Also after closer examination the part number on the board apears to be Q19701. I have a possible part # for the board RCA 250686. Any body know a source? Thanks!

×

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.

    Genius:

    An expert who has answered 1,000 questions.

  • RCA Master
  • 1,550 Answers

The real number are on the front of the scr body check it

Posted on Aug 22, 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

Can not find parts for Chicago electric 200 amp welder


You may not need to replace the board if the wire feed failed- most often it is an SCR or pair that has failed. Usually what is used is a 6 amp 600 volt SCR- you can go higher current and voltage for reliability. just make sure the heat sink is adequate or larger and heat transfer compound is used. Digi Key carries the "Teccor" SCR's other brands of the same or higher ratings will work.

Sep 16, 2012 | Welding Tools

5 Answers

Matsui dabr103 radio display lites up blue with no onformation no sound Mine does that, plug it in just get the blue display. Nothing else.


First try unplugging the power cord for five minutes.

If it does not work try pressing power button for ten seconds.

If still no luck, then it is faulty.

Oct 18, 2008 | Audio Players & Recorders

2 Answers

The red light just stays on .I changed the fuse and the same thing


Needs to get a Depot service done for the Electronic board. Could be an issue with Capacitor or IC. Good luck.

Jan 07, 2011 | Pyramid (PS36KX) 600-Watt Power Supply

1 Answer

Power tv on and then it clicks and turns off


Most of the time there are one or more 5 amp pico fuses open on the power supply. The cause of them opening is the +/- 30 volt line shorting from the convergence circuit. If you take this repair on yourself and are familiar with a ohm meter, you can check the small green pico fuses in the power supply. Remove the power from the set, take the back off. The board in the center is the power supply and convergence circuit. In the center of the you will a transformer. Just to the left of the transformer you will small green fuses that look like resisters. They are marked on the board but are sometimes hard to see. If one is open for the 30 volt line, the convergence IC's need to be replaced. They are mounted on the back of the large heat sink and the board must be removed to replace them. When you remove the board, be sure to remove all the screws not only around the edges of the board but also in the center too. There are also screws on each end of the heat sink and on the blind side center foot securing a ground wire. On each side of the board there are plug clips that must be lifted. At the front of the board there are plug connectors that need to be unplugged. Once the board is removed the IC's are easy to replace. Remove them from the heat sink, Unsolder them from the board using solderwik. The Convergence IC's should be STK392-570. If there is only one, it is a STK393-110. When replacing them, I recommend using heat sink compound on the back of the IC's where they contact the heat sink. solder in the new IC's then attach the heat sink to them.
Replace the small pico fuse or fuses, they should be rated at 5 amps. Once all the parts are replaced, remount the board making sure the heat sink holes align with the board holes. Reconnect the plug connectors, Plug clips, and reinstall all the board screws.

I hope this helps,
Skyassoc

Dec 12, 2010 | Mitsubishi WS-55809 55" Rear Projection...

1 Answer

Loud crack when turning unit on, blows main fuse no lights come on.. bottom of power supply black and signs of burn...


DO NOT REPLACE THE FUSE !!! You will do more damage.

I just repaired one of these. A small ceramic surface mounted cap very near where the +/- 85 volt connectors plug onto the board blew up.

This left a sputtered mess on the insulating material at the right rear corner of the power supply.

The net parts list of parts I had to replace:

1. Main IGBT transistors on heat sinks. You have to remove the heat sinks to get at the mounting screws. 1MBK50D or equivalent. I used DigKey part APT28GA60BD15

2. One 1N4148 surface mount diode that is for gate drive speedup. D24 and D25. (don't remember which one was shorted)

3. All four driver transistors for the gate of the IGBT's. @ each 2SA1020 (PNP) and 2SC2655 (NPN). These are tall TO92-like transistors and I believe that at least one of these I had to get from Mouser.

4. Transistor T9, suface mount BC856B (PNP)

5. Replaced all four surface mount caps, one had exploded.
C50, C51,C54,C56. Replace with 0.01mfd/200 Volt 1206 style surface mount caps Digikey 478-1511-6

6.Replaced ceramic wire wound 10 Watt stand up resistors that were blown open. Replaced with 20 ohm design change. These slowly charge the main input filter caps and when supply is stable, a relay shorts them out. If you have replaced the fuse, you LIKELY blew them out. Original value was 10 ohms on some units. This was a Mouser part. 280-PRM10-20-RC

7. The 2153 switching reg chip IC1. This chip shorts. It is made by International Rectifier and I believe the full number is something like IRF2153. I had these in stock and not sure of which source I had procured them from... It was from one or the other.

Lots of destruction and one really needs a desoldering station to work this. Removal of the blown IGBT's is especially tough. All solder must be removed from the transistor leads AND the thermistor on one of the heat sinks. Once you have verified the leads are loose, one has to rock the heat sinks to get the tabs free. The tabs are NOT soldered! Be careful when restoring to get the thermistor leads started in their holes.

Note: ALL these repair parts were procured from DigiKey.com and Mouser.com. Neither of these places had all, I had to order from both. Mouser had the ceramic resistors.

When restarting this, leave outputs disconnected until it is running again. USE a series 75 watt light bulb in the 120 volt input. ONLY work on the unit using an isolation transformer as a large portion of this is connected right to the power line.

There is a small 15 volt switching supply that comes on first that runs the relay to short out the inrush limiting resistors. With the 2153 shorted as usual, this auxilary supply can't reach voltage enough to turn on the relay. The power for this is supplied through the ceramic resistors.

May 08, 2010 | Behringer Pmp3000 16 Channel Audio Mixer

2 Answers

Tv turned itself off. turn power back on, picture


Your TV is experiencing a convergence issue as indicated by the 3 blinks. The only way to fix this is replacing the convergence ICs. It is not a hard task to replace these ICs. You just need to know how to solder and work on printed circuit boards.

The convergence ICs are mounted on a large heat sink and are marked with codes starting with the letters STK and there are two of them. You need to replace both.

Look for the heat sink with two ICs mounted on it and check the markings.

Once found, cut the IC legs with a small side cutter and unscrew it from the heat sink. Remove the legs left soldered on the board.

Take note of the IC markings for ordering the right part and how it was installed. Don't forget to buy along with the IC a thermal compound.

Check the pico fuses on the same board. Most likely you will find a blown one. These fuses look very much like a resistor, not like the usual transparent fuse, and usually yellow.

Once you have the replacement ICs, put it on the board in the same way as it was installed before. Make sure the screw holes are aligned before soldering the legs into the board.

Put a reasonable amount of thermal grease/compound between the ICs and the heat sink and fix them with the screws.

Double check the board for any splash of solders that might cause a short circuit and damage the board.


Dec 07, 2009 | Panasonic PT-47WX53 47" Rear Projection...

1 Answer

Hobart handler 135 feed motor for wire doesn't feed wire. motor is ok I tested it with seperate power source. No power to motor from main board or ??????


check the SCR ,looks like a big transistor mounted
to a heat sink or some of the older units had a relay
in-line with a fuse , I have a older Hobart and it is
a great little welder. If you snap a pic of the P.C.
board and email it ill rsheehan@northernsteeldesigns.com

point out what parts to check.and replace.

Rob

Dec 06, 2009 | Hobart Handler 140 Mig Welder

1 Answer

Hi. i have a 54 inch samsung rear projection tv. 2 years ago something happend within the tv and the picture was doubled. and there were red lines going through the tv. i had sears come out today and look...


Hi,
This sounds like the most common thing that fails on projection TV's, regardless of the brand. The convergence circuit has two, or sometimes three STK IC chips mounted on heat sinks to drive the convergence yokes. They typically last anywhere from 5-10 years, then they fail.

It sounds like in your case, the solder joints on the bottom of one of these chips may be failing and some fresh solder will make it go for a while. I would recommend you to replace both the STK chips.
These ICs are used to align and keep aligned the three colors on the screen...

INSTRUCTION TO REPLACE CONVERGENCE ICs:

The parts you will need are two ic's that are referred to as STK ic's. This is in reference to the first three letters of the part number. You will also need some pico fuses. The pico fuses are little yellow fuses that look like resistors. When they blow, they will show no physical sign of failure. The amperage rating will be printed on the fuse. For example a 5 amp fuse will have the number 5000 on it. A 3.15 amp fuse will have the number 3150 on it. You will need to use an ohm meter to test these fuses

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.

When replacing the STKs make sure you use heat sink compound on the back of the ic's before installing them. Also as a rule of thumb, screw or clamp the ic's down to their heat sinks before you solder the pins. Replace any blown pico fuses and re- install your boards. When you turn your set on it may still be out of convergence due to many factors. Try pressing the auto focus button on front of your set.

Rate this solution
Rnj VINODKUMAR

Nov 11, 2009 | Samsung Televison & Video

1 Answer

Hi i have a RCA P52937SG with the bowing of the screen


The problem may still be on the power supply board (one of the supplies may be missing and) when you unplug the supply both supplies go missing check the supply voltages and repost

Oct 14, 2009 | RCA P52937 52" Rear Projection Television

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?
RCA P52960 52" Rear Projection Television Logo

Related Topics:

191 people viewed this question

Ask a Question

Usually answered in minutes!

Top RCA Televison & Video Experts

The Knight
The Knight

Level 3 Expert

72601 Answers

matt martin
matt martin

Level 3 Expert

1207 Answers

Jaime Hernandez

Level 3 Expert

2296 Answers

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

Answer questions

Manuals & User Guides

Loading...