Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
The real Andy
 
Posts: n/a
Default Philips tv, not remembering last channel:no battery and no supercap.

"Jim Lazzaro" wrote in message
om...
If anyone could please advise me about what keeps the memory of the
last channel viewed before switch off.
TV is a Philips 14CN2001/75S, it doesn't have a remote.
I am unable to find any batteries or supercaps.
The problem is when switched on the TV starts on channel 0 (sound is
okai)regardless of what channel it was used on.
Unfortunayely I do not have schematics and also I don't see any eeprom
on PCB.


EEPROM is probably incorporated into the micro that controls the TV. IT
might pay you to track down the service manual from High Country,
hcsd.com.au I think.


  #2   Report Post  
Rudolf Ladyzhenskii
 
Posts: n/a
Default Philips tv, not remembering last channel:no battery and no supercap.

Do you switch it on at AC power or from stand by?

It should remember channel when you do from stand by, but it does not have
to when you do at mains.
If yoour PP (sound, brightness, etc...) stay same and channel tune is OK, I
would think memory backup is fine.

Rudolf

"Jim Lazzaro" wrote in message
om...
If anyone could please advise me about what keeps the memory of the
last channel viewed before switch off.
TV is a Philips 14CN2001/75S, it doesn't have a remote.
I am unable to find any batteries or supercaps.
The problem is when switched on the TV starts on channel 0 (sound is
okai)regardless of what channel it was used on.
Unfortunayely I do not have schematics and also I don't see any eeprom
on PCB.
Thanking you in advance.
Jim


  #3   Report Post  
Jerry Greenberg
 
Posts: n/a
Default Philips tv, not remembering last channel:no battery and no supercap.

I have not worked on this model, but can be general.

This can get fairly compex for the novice. If you want to fix this
yourself, you would have to invest in the service manual and see how
your particular model does the memory operation. You will have to
understand the schematics, have the proper tools, and follow procedure
to locate the fault.

The problem is most likely associated with the main uPC. There may be
a CMOS ram or an EEPROM involved. Depending on the design, this can
be an integral part of the uPC, or some other IC device. Some sets
also have a cap, or battery for this function. There are a number of
ways that the memory is retained.

I have also seen firmware problems in sets where the uPC, and or the
IC that does the memory control and function be replaced. If this is
the case, the associated IC's had to be replaced. I have also had some
support components for the controler area fail, thus causing memory
problems.

I would suggest you give the set to an authorsed Philips service rep
if you are not able to do this type of service. This is very
specialized work.



Jerry Greenberg

--




(Jim Lazzaro) wrote in message . com...
If anyone could please advise me about what keeps the memory of the
last channel viewed before switch off.
TV is a Philips 14CN2001/75S, it doesn't have a remote.
I am unable to find any batteries or supercaps.
The problem is when switched on the TV starts on channel 0 (sound is
okai)regardless of what channel it was used on.
Unfortunayely I do not have schematics and also I don't see any eeprom
on PCB.
Thanking you in advance.
Jim

Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Installed new battery backup for home alarm Redtag UK diy 68 December 17th 03 09:41 AM
Lowest Battery voltage John Electronics 8 December 16th 03 01:16 AM
OT Replacing the batteries in a cordless drill battery pack aribert Metalworking 7 December 4th 03 12:41 AM
Welder as battery charger?? Cory B Electronics 8 August 18th 03 06:09 AM
Car and Motorcycle Battery Tips Bill Darden UK diy 4 July 15th 03 03:49 PM


All times are GMT +1. The time now is 03:46 PM.

Powered by vBulletin® Copyright ©2000 - 2023, Jelsoft Enterprises Ltd.
Copyright 2004-2023 DIYbanter.
The comments are property of their posters.
 

About Us

"It's about DIY & home improvement"