20 Most Recent Panasonic PT-40LC12 40" Rear Projection HDTV - Page 3 Questions & Answers

There is only 2 things that will cause this and one is Dirt on optical Lense OR Light Engine is going BAD if light engine is it it will start showing more spots along with tiny DOTs and color on picture will be green and purple in different areas.

Panasonic... | Answered on Aug 19, 2009

For the full instructions and how to reset the lamp timer go to the following site

I hope this information allows you to resolve this issue.
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Panasonic... | Answered on Jul 31, 2009

There is a side panel where the Lamp is located and held on by a screw or two.
Open that compartment and vacuum out all dust. Also any fans should also be cleaned.

Panasonic... | Answered on Jul 30, 2009

While TV is on, simultaneously press and hold both the TV's Volume Down button and the remote's PP/Play button for 7 seconds.

Panasonic... | Answered on Jul 29, 2009

you will have to open back of tv, then there is a door that you can open and pull out the bulb.
purelandsupply.com is usually the cheapest

Panasonic... | Answered on Jul 09, 2009


Panasonic... | Answered on Jul 07, 2009

Problem is the bulb.
I had this exact same problem.  Even though the bulb appears to be good, it is drawing too much current to run properly, and the ballast is shutting it down.

Panasonic... | Answered on Jun 25, 2009

Is the lamp new. A lamp can look ok but still be bad. This is first thing to change. You'll have a spare if not bad. next likely the ballast.

Panasonic... | Answered on Apr 25, 2009

Probably the ballast if lamp is ok.If there is not even a standby light the the power supply.

Panasonic... | Answered on Apr 25, 2009

Soulvisitor has it right. I had the same problem and the stupid tv would shut off after 1 minute. We opened the silver front panel , took the bulb out cleaned it, took the cover off the grey box to the right and very carefully vaccumed the filter and wiped it off with a microfiber cloth. It works great now!!! Make sure you unplug your tv before messing with it. Thank you Soulvistor you saved us at least $100.00

Panasonic... | Answered on Mar 29, 2009

on about the hdmi lead

Panasonic... | Answered on Mar 22, 2009

Found that the thermistor/temp measuring device is suspect, no resistance across legs. There is a label there that says F701 see service manual
I went here for a tech manual for the Panasonic tv1.gif.
then ordered
Manufacturer: Panasonic
Part Description: FUSE
Part Number: LSJA0411-1
from PartStore.com
it was mounted to the case that holds the lamp. had to remove the back panel, etc. Also think I had to splice in the fuse or something. was a while ago.

i purchased a NTE8115 from my electronics supplier, closest I could find. Radio shack1.gif also has them.

remove the back cover and measure for continuity across the thermal fuse
above the lamp housing.
if open jump it wth a 5 amp fuse, be sure to close the safety switch with
the small blue lever then try to power on.
If comes on ok you will need to replace the entire ballast assembly to get
that fuse.
Panasonic does not have a part number for just the fuse on the PT40LC
It is possible to cut off the fuse and replace with another but dont solder
must be crimped.

Panasonic... | Answered on Mar 16, 2009

Can't be 100% sure but the most likely cause of the problem is bad solder connections in the switch mode power supply or on the vertical output IC, or anywhere on the main or picture tube circuit boards, due to age and switching on and off TV's develop bad solder connections when cold the connection is made and when it warms up due to heat expansion the connection breaks, you will need to be handy with a soldering iron, and discharge all power supplies with something like a 100 Watt globe before soldering or you may blow things up and do really serious damage, and be warned TV 's have very high voltages 360 volts DC in the SMPS primary and over 20,000 volts to the picture tube, so be careful.

Panasonic... | Answered on Mar 09, 2009

At first i was thinking the ballast had gone bad but after reading a few other post i think it would be best to call pannasonic..
others forums read:
ballast had gone bad. Panasonic no longer makes these ballasts so mine needed to be rebuilt at the tune of $400.00.

With the ballast in place still nothing so now they claim that they need to order a "kit" from Panasonic which basically is all the components of my tv.

Panasonic... | Answered on Mar 06, 2009

Do you mean thermister? And if so, there may be more than 1...
One probably on the main transformer, one on the audio amplifier transistors, others on other transistors that may get hot. Look for heat sinks - they are usually located on top or affixed to those.

good luck

Panasonic... | Answered on Mar 04, 2009

Had similar issue but had high resistance across leads. replaced with thermal fuse from RadioShack in the similar temp and everything works great. Info on the original part is on this link. http://www.willas-array.com/prod/products/directory/pdf/sefuse/FUSE_SMG.PDF Hope that helps. Chris

Panasonic... | Answered on Feb 26, 2009

Try the following:
While pressing the Vol-(volume down) button on the TV front panel, hold down the PIP button on the remote control at the same time for more
than 5 seconds. When the reset procedure is complete the following message will appear on the screen. "Lamp time was reset to 0".

Panasonic... | Answered on Feb 26, 2009

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