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chumba
Joined: 01 Jul 2009
Posts: 66
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 Posted: Tue Mar 23, 2010 5:43 pm Post subject: |
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Shorting pins 3 & 8 of connector TP displays CHK in yellow. Pressing the action and volume up buttons on the TV turns the CHK display red in upper left side of picture. (nothing works with remote).
However pressing the action and volume down buttons on the TV repeatedly does not select any service modes -- all that comes up is the usual 8 boxes (setup, channel labels, etc.) like the Action button was pressed.
Pressing Action + Power buttons does exit the service mode. |
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JTS1957
Joined: 21 Jan 2009
Posts: 1331
Location: Far, Far Away
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| Posted: Tue Mar 23, 2010 11:41 pm Post subject: |
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If I had a spare chassis  , I'd try swapping the EEPROM (only 8 pins) then the microprocessor. |
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chumba
Joined: 01 Jul 2009
Posts: 66
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| Posted: Fri Mar 26, 2010 5:46 pm Post subject: |
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| What part number is the 8 pin EEPROM ? Any way to test it? |
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JTS1957
Joined: 21 Jan 2009
Posts: 1331
Location: Far, Far Away
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| Posted: Fri Mar 26, 2010 9:06 pm Post subject: |
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24LC02BIP
No definitive Good/Bad test.
Without an EEPROM programmer, all you can do is see if it has 5 volts b-plus on pin 8 and almost 5 volts on pins 5 & 6. If you have O'scope, these two should show pulse activity when, for example, channel up button is pressed. |
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chumba
Joined: 01 Jul 2009
Posts: 66
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| Posted: Sat Mar 27, 2010 6:50 pm Post subject: |
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IC002 measures 5 Volts DC on pin 8 and about 3.4 volts on pins 5 & 6.
Is there a way to hard reset this chassis (by possibly shorting connector/TP pins together or button combinations)?
Also if I buy a new off the shelf microprocessor and/or EEPROM, would either require additional "programming" to work correctly, or can they just be installed directly out of the box? |
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JTS1957
Joined: 21 Jan 2009
Posts: 1331
Location: Far, Far Away
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| Posted: Sat Mar 27, 2010 9:30 pm Post subject: |
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None that I know of.
Micro, if obtained via a authorized Panasonic parts distributor, with a Pana part number will be plug-n-play (soldered), EEPROM should be preprogrammed with "representative" values for parameters and may require touch-up of the geometry and CRT grey scale ones, at least.  |
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chumba
Joined: 01 Jul 2009
Posts: 66
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| Posted: Tue Mar 30, 2010 6:22 pm Post subject: |
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| Any other suggestions to try before I chuck it? Do you think it is worth spending over $50 additional in parts that may or may not fix the problem for a 12 year old TV? |
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JTS1957
Joined: 21 Jan 2009
Posts: 1331
Location: Far, Far Away
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| Posted: Tue Mar 30, 2010 6:41 pm Post subject: |
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| Sorry. I just answer the questions (as best as I can), I don't pretend to make the final decisions. |
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chumba
Joined: 01 Jul 2009
Posts: 66
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| Posted: Tue Jun 22, 2010 1:14 pm Post subject: |
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| The microproc is no longer even available from Pana nor its authorizized distributor. What is your take on getting the part from a non-Pana source such as MCM...."programming" will be an issue I take it? |
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JTS1957
Joined: 21 Jan 2009
Posts: 1331
Location: Far, Far Away
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| Posted: Tue Jun 22, 2010 6:16 pm Post subject: |
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Some TV repair shops have "boneyards" with junk chassis that they've been stripping parts off of.
Craigslist / ebay / curb on garbage day, etc.
Unless you obtain a "blank" chip ... programmer would need a good chip to "read" before he can "write," unless the programmer has it "in memory," or you are able to access a "bin file"/"dump." |
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