Ballast Repair Kit for Panasonic PT-40LC12 and PT-45LC12

This thread is basically a continuation of http://www.avsforum.com/avs-vb/showthread.php?t=958640

Based on brogers' thread, I ordered the same ballast repair kit intented for the Panasonic PT-xxLC13 series and applied it to the Panasonic PT-xxLC12 series.

Please note that the following information is provided at your own risk. What worked for me may not work for you. This procedure involves soldering and electronic experience!

Apparently, after many ballast and bulb failures, Panasonic put out a kit of components marketed as the "Panasonic Ballast Repair Kit", #LSUC0022. This kit contains 1 transistor, 1 resistor, 2 diodes, 1 capacitor, and 1 fuse. The purpose of this kit was to replace probable defective components on the Ballast circuit board.

There are two versions of this repair kit. The older version, LSQL1865, contains the original parts supplied to the PT-xxLC13 family. The newer version, LSQL1865-1, contains newer equivalent parts that were supplied to the newer PT-xxLC14 and later families of Panasonic TVs. If you have a choice, I would get the newer version, as there may have been improvements to the componenents.

I received the older version (not by choice), whereas brogers received the newer version.

http://www.elirion.net/~tomwil/Panasonic/PT40LC12a.JPG

The kit matchups are listed here, and where each component gets installed:


LSQL1865 LSQL1865-1 PT-50LC13 PT-40LC12 Description

1. B2ZAZ0000020 B2ZAZ0000020 D1315 D1317 Diode
2. D1FZ100E0001 D1F5100E0002 R1305 R1703 Resistor
3. MA2Q73600L MA2Q73600L D1301 D1701 Diode
4. LSSF0013B50T K5D502BNA005 F1301 F1701 Fuse
5. B1DEGQ000011 B1DEGQ000044 Q1306-9 Q1302-6 Transistor
6. F0CAH104A001 F0CAH104A001 C1330 C1314 Capacitor


The PT-40LC12 combines the LCD power supply (1700 series) with the ballast (1300 series) on the same circuit board. Therefore, the component locations are different on the PT-40LC12 than what is mentioned in the kit for the PT-50LC13.

Also note that this kit contains only one transistor, whereas the PT-40LC12 and PT-50LC13 has at least 4 transistors. It might be worthwhile to order additional transistors and replace them as a set.

Also to be noted, the ballast on the PT-40LC12 is buried underneath the bulb housing, unlike the PT-50LC13 which is located right at the rear of the set. Therefore, the PT-40LC12 needs major unassembly to get to the ballast.

Here are the steps needed to get to the ballast:

1) Unplug the TV you are going to work on.
2) Remove the TV rear cover by removing 20 screws.
3) Remove the AV flip-down front door.
4) Remove the front left and right speaker covers.
5) Remove the front center panel by removing 4 screws, and unplugging connector P6303.

http://www.elirion.net/~tomwil/Panasonic/PT40LC12b.JPG

6) Remove the lamp cover door.
7) Remove the lamp housing (that contains the bulb).
8) Open the front base panel by removing 16 screws. Remove the ground strap screw so that the base front panel can lay down.

http://www.elirion.net/~tomwil/Panasonic/PT40LC12c.JPG

9) Unplug connectors P1010 and P4504 from the main circuit board.

http://www.elirion.net/~tomwil/Panasonic/PT40LC12d.JPG

10) Remove 4 screws that attach grounding straps and grounding plates to the ballast.

http://www.elirion.net/~tomwil/Panasonic/PT40LC12e.JPG

11) At the rear of the set, remove the duct fan by removing 4 screws. Unplug connector P804 from the main circuit board.

http://www.elirion.net/~tomwil/Panasonic/PT40LC12f.JPG

12) Remove the Audio Power unit by unplugging connector P1101 and removing 2 mounting screws.

http://www.elirion.net/~tomwil/Panasonic/PT40LC12g.JPG

13) Remove the 10 screws as shown. Basically, you are removing 2 screws to release the lamp socket on the lamp housing. Then remove 2 screws to the temperature fuse on the lamp housing. Remove 1 screw to the ground plate and ground wire on the lamp housing. Remove 1 screw to the ground wire on the ballast. Remove 2 screws that hold the ground plate to the ballast. Unplug connector P1905 from the LCD Main circuit board. Finally, remove 2 mounting screws that hold the ballast cage to the base, and lift the ballast cage out of the set. See diagram.

http://www.elirion.net/~tomwil/Panasonic/PT40LC12h.JPG

14) Pry off the cover to the ballast cage. Unplug connector P1703 and fully remove the cover.

http://www.elirion.net/~tomwil/Panasonic/PT40LC12i.JPG

15) Remove the ballast circuit board from the cage by removing the 3 mounting screws and lifting the circuit board from the posts.

16) Locate each component as shown. Each component name is clearly written on the circuit board. Replace the components with the new componenents from the kit. Note polarity especially with the diodes. This procedure involves soldering and electronic experience!

http://www.elirion.net/~tomwil/Panasonic/PT40LC12j.JPG

http://www.elirion.net/~tomwil/Panasonic/PT40LC12k.JPG

17) Reassemble everything in reverse order. Take your time, and pay attention to reconnecting all the connectors and grounding plates, straps and wires.

If you notice anything missing or inaccurate with these instructions, please let me know. Sorry for the watermark on the pictures; they are to help prevent the sale or misuse of these instructions. Thanks to brogers for initiating this process!

Thank you VERY much for re-posting this

Greetings. First of all, many thanks for the excellent assistance offered in this thread. It savedme much panic and hair pulling.
I have a PT-45LC12 TV, and yes, I hate the low life of the bulb. Yesterday I turned on my TV to find flashing green light, no picture. Upon investigation on the web, I found your site (among others) talking about the thermal fuse and the ballast repair. I popped the back of the TV off, checked the obviously placed thermal fuse with my multi-meter, sure enough, no continuity. Snipped it off, temporarily crimped the wires together, TV works. My local electronics store has a similar thermal fuse (117 c instead of 115c) which I will pick up tonight on the way home and crimp into place.
Questions.
1. Any evidence out there that a blown thermal fuse is an indication of further problems? I deal with thermal fuses in my work, so I know sometimes they just die, for no good reason, just "your time is up"

2. Is there any compelling reason to go through the hassle (and possible danger of damaging components) to replace the components in the LSUC0022 repair kit (best price I have found is tristatemodule $15.89 plus shipping, minimum shipping $7.95) Will replacing the components (specifically the capacitor,which I read has a different value than the one stock in the board) possibly avoid future problems or extend the life of my bulb?

Thank you again for all the great helps, photos, instructions and hand holding for these problems. (I wonder why they didn't include a thermal fuse in the ballast repair kit)

1. Any evidence out there that a blown thermal fuse is an indication of further problems? I deal with thermal fuses in my work, so I know sometimes they just die, for no good reason, just "your time is up".

It probably just blew from age and usage. However, if the new one you install blows, then it might need more investigation.

2. Is there any compelling reason to go through the hassle (and possible danger of damaging components) to replace the components in the LSUC0022 repair kit? Will replacing the components (specifically the capacitor,which I read has a different value than the one stock in the board) possibly avoid future problems or extend the life of my bulb?

I believe the repair kit was offered to solve the "bulb not lighting" problem. Whether it protects or extends the life of the bulb is not really known.

As far as the capacitor, according to the Panasonic parts list the replacement capacitor in the kit is the same value, but probably bigger and beefier.

If your set works normally after the thermal fuse replacement, it would probably not be worth the risk of installing the ballast kit.

d1701 is not marked on the old diode or on the board for the relay. I know a diode is needed to keep current going to ground when the field breaks down so which way is south? I should'a measured it first before jumpimg in. I'm trying to get it running by Christmas. in ref to gnd the line goes where? North
Edit
OK, made me look. service manual is usless here. "unit replacement" I see gnd on one side only. I am assuming the line is not on gnd.

d1701 is not marked on the old diode or on the board for the relay.

Reference here (http://www.avsforum.com/avs-vb/showthread.php?p=15372540#post15372540).

I just inherited a PT-40LC12 after a friend gave up on it. He replaced the bulb a couple of times and then it started flashing codes to him.

When the unit is first turned on, the green light flashes a few times and then the warning message is displayed that the lamp has to be replaced. This is shown for about 20 seconds, and then the lamp shuts down. The TEMP lamp flashes 4 times every 5 seconds or so. I've tried resetting the lamp timer, but the lamp shuts down before the timer is reset. Looking at this and other forums, I tried replacing the thermistor located on top of the lamp cage, but still get the same response.

Any suggestions?

The TEMP lamp flashes 4 times every 5 seconds.

The service manual indicates that the code means the air filter needs cleaning, or replacement.

The service manual indicates that the code means the air filter needs cleaning, or replacement.
The air filter looks nearly brand new. Is there a sensor that might be bad?

The air filter looks nearly brand new. Is there a sensor that might be bad?

You seem to be experiencing the same problem as this post (http://www.avsforum.com/avs-vb/showthread.php?p=14447605#post14447605).

His solution was to unplug and replug the connector to the lamp thermistor (the small circuit board mounted above the lamp cage).

The purpose of the lamp thermistor is to detect overheating of the bulb. If the thermistor is bad, it can be replaced ($4 part #D4CE31330001).

The part you originally replaced was the temperature fuse, which is different from the thermistor.

Tom,

Thanks for the suggestion. I had replaced the fuse instead of the thermistor. I just replaced the thermistor, but still don't have a working unit. The behavior has changed slightly, however. Now, after the lamp turns off, I get 4 quick flashes of the temp light, then a few seconds later one long flash. That cycle repeats. Any ideas?

Thanks again!

Paul

Paul -

You have two errors going. I am going to give you what is mentioned in the service manual.

Temp LED flashes once every 5 seconds

Cause: detects open or short of the Temperature Sensor (R2911) on Front Thermistor C.B.A.

Resolution: Replace the Temperature Sensor (R2911) on Front Thermistor C.B.A. If still No Good, replace the Projection Unit. Note: The Projection Unit includes LCD Main C.B.A.

Temp LED flashes 4 times every 5 seconds

Cause: detects the temperature attached near the Lamp by the Temperature Sensor (R2901) on Lamp Thermistor C.B.A., then indicates the error when the temperature becomes more than 60 C (140 F).

Possible causes:

1. Clogged air filter.
2. Blocked air intake.
3. The surrounding temperature of the place of use may be too high.

Resolution: Cleaning the Air Filter.


The above is what is mentioned in the service manual.

The least expensive repair is the check or replace the front fan thermistor, ~$3.50, #D4CA35030002. The projection unit is very expensive.

You might also want to check the filter and the way it seals, to insure no blockage. Also, check both the front fan and lamp fan, and be sure both are spinning at a reasonable rate.

Hope this helps!

I have a PT45LC12 and replaced the bulb (not the entire lamp assembly) in September with an Osram bulb I got from River Valley Electronics after the original bulb blew (worked for 4-5 years). Recently I've started to get the problem where the picture will come on for 10-30seconds and then the lamp shuts off, the fan keeps running, and the lamp light flashing 4 times, pause, flashes 4 times which keeps repeating until I hit the power button again.

I've done quite a bit of searching on the net for this problem and have found people mentioning it but no indication of a fix. A post on another forum gives this info (which comes from the repair manual):

"That is the blink code for the lamp ballast. Here is the more complicated explanation from the service manual.

IC2301(pin11) detects the error of LCD Power C.B.A. and Lamp,
then indicates the error when an inner malfunction of LCD Power
C.B.A. occurs, the Lamp voltage becomes more than 130V or
less than 30V, Lamp current becomes more than 5A, or the Lamp is blown."

I don't exactly know what the above means...So my (uneducated) thoughts:

1)The lamp itself? There's alot of discussion on the pros and cons of OEM/non-Panasonic bulbs vs the entire lamp assembly direct from Panasonic so this could be the problem. I also assume that a bad bulb could be the cause of the error that seems to be propagating to some board somewhere. I'm just wary as a)someone in one of the other threads I found mentioned that putting in a new bulb did not fix this problem, b)the lamp itself does work for about 30secs until the TV decides to shut it off, and mainly c)shelling out 300bucks on the chance it fixes my problem isn't that desirable while there are cheaper methods to try.

2)Alot of people mention that similar problems (but not this exact one) have been fixed by replacing the thermal fuse or the thermistor. Could a bad/old fuse or thermistor make the system think there is a problem with voltage or amperage? After opening up the back of the TV and finding these parts, this definitely looks like something I can do so I'll be trying this as soon as the parts come in.

3)Using the ballast repair kit detailed in this post? This also seems cheap enough to try but seems to be well past my skill set to attempt. This one may take a while to attempt while I round up a skilled electronics guy. As this TV is on the old side, I don't want to take it to a repair shop and get charged hundreds of dollars to fix it when this post makes it sound like a electronics enthusiast could do the work in an hour or so...


So, I guess I'm posting to see if anyone on these forums has any other suggestions for things I could try?

Or if someone checking these forums has found a fix for my problem?

Jwburt -

Never had your problem.

But you seem to have figured out most of the possibilities.

It is probably your lamp that is causing the problem. For some reason your TV circuitry is detecting abnormal voltages with your bulb; it's probably drawing too much current to keep lit. If it was temperature related, the temp light usually flashes instead.

I don't think the temperature fuse or the thermistors are causing your problem, but they are inexpensive to replace.

That leaves pretty much the lamp or the power supply (ballast).

You could try reseating the connections between the thermistors, lamp, power board, and the main board. Maybe a high-resistant contact is causing the problem.

Not sure if the ballast repair kit would help your problem. Usually the kit is used to solve a non-starting lamp, although other benefits are not known at this time.

The true Panasonic lamps appear to solve most problems. The other "OEM" lamps seem to be a crap-shoot ... maybe they work, maybe they don't. And, those "OEM" lamps seem to have a very short lifespan if they do work initially.

Please let us know how you solve this. Thanks!

Hello,

I have read through nearly all of this forum starting with Broggers original post. But, I have not seen my specific set of symptoms.

The television will not turn on at all, which seems to indicate the ballast repair is needed. In which case the first diagrams on this forum for the 45LC12 would be great, thank you!

However, it is not just throwing the lamp error light. The specific sequence is:

1) Upon plugging it in the power led goes from green, to two yellow flashes, to red.

2) The temp led flashes

3) after a few seconds of gap, the Lamp LED lights and stays lite for 5 seconds

4) the power led flashes red again

5) then the temp led flashes once followed by a four second gap then the lamp led for 5secs

6) the total cycle takes 15secs

Does this mean it is both the front Thermoster and ballast need to be replaced? Or is this beyond fatal?

Thanks! :eek: :confused: :eek:

I have a PT-40LC12. This morning I tried to turn it on I can hear it powering up but after awhile of the green light flashing it turns to flashing red then powers down. What can this be?:confused:

I have a PT-40LC12. This morning I tried to turn it on I can hear it powering up but after awhile of the green light flashing it turns to flashing red then powers down. What can this be?:confused:

Usually it is either the bulb or the ballast.

There is a chart of the blinking lights here (http://www.avsforum.com/avs-vb/attachment.php?attachmentid=141714&d=1241461185).

Hello,

My in-laws have a Panasonic PT-40LC12. And im trying to get to the bottom of why its not working! I tried powering it on yesterday and the GREEN POWER LED light keeps on flashing and nothing would display on the screen. So i went to go look at the service manual, they said to check the to see if the Rear fan was on. And the fan was, so they directed me to the temp. fuse. But after reading this Thread im kinda stump on what to do now.

Please let me know on what i need to do???????

Anyone please????

There have been many posts here about this model. Could be lamp or could be Ballast. Lamp is TY-LA1000 for about $100. Ballast is $600 - $300 parts/$300 Labor. or a You Fit it kit #LSUC0022 for about $20 which you would be soldering 6 diode/resisters to circuit board.

I have a PT-60LC13 for 5 years and have replaced 3-4 bulbs. Just replaced the bulb two weeks ago and then went out again. 140 Green blinking LED lights - then 5 Red - 1 Yellow, means light and ballast bad. Thread above has
service manual page explaining the blinking lights. Good Luck.

I have the PT-45LC12 Panasonic. I was watching the unit just shutoff. Didn't make the dreaded pop from the bulb blowing. It just shut off. I looked at the bulb it seems to be fine. Now the Green light just flashes and thats it. I don't hear the fans or anything... Please help I would hate to throw this tv away if it's something simple.
Thanks

We just replaced the bulb in our PT-45LC12 and now it takes up to 4 minutes for the TV to turn on... we get a blue screen when turned on and then the tv picture finally turns on... any ideas of why this may be happening?

Hello,

My in-laws have a Panasonic PT-40LC12. And im trying to get to the bottom of why its not working! I tried powering it on yesterday and the GREEN POWER LED light keeps on flashing and nothing would display on the screen. So i went to go look at the service manual, they said to check the to see if the Rear fan was on. And the fan was, so they directed me to the temp. fuse. But after reading this Thread im kinda stump on what to do now.

Please let me know on what i need to do???????

Exact same issue with the PT-45LC12 with one side effect... the front fan on the right if looking at the front of the TV doesn't spin.

Where can I throw away this tv? I bought it used from a friend for 300 bucks... there's no way I'm paying 600 bucks for a part, the lamp was the most I was going to spend, but if I can get away with just replacing the fan cool, but if I get it replaced and it still doesn't work. bah.