1. Home
  2. Electronics Repair
  3. Panasonic 27XF25CW 27" TV Horizontal Line until warms up

Panasonic 27XF25CW 27" TV Horizontal Line until warms up

Hi, I'm a new user to this group. I have the above TV - GAOO, circa

2006,with the following symptoms. When the TV is turned on and cold, there is bright horizontal line in the middle of the screen with a flickering picture in the top half of screen and bottom 1/2 is black. As the tv warms up, the image does eventually fill in and the whole screen is more or less viewable. The mid-section does continue to have some flickering lines, however, is still reasonably viewable. Can anyone direct me to whether this is a low voltage or HV issue? Is this reasonably repairable or is it IC's etc all surface mount. Appreciate any help.
Reply to
bluespark
Loading thread data ...

The symptoms would indicate a bad solder joint in the vertical deflection circuit (probably on the vertical deflection IC) or a bad capacitor in the vertical deflection area.

This is definitely repairable by a competent technician, but do you know enough about TVs to locate the suspect components and to work safely?

PlainBill

Reply to
PlainBill47

On Sat, 13 Mar 2010 17:29:09 -0800 (PST), bluespark put finger to keyboard and composed:

The symptoms suggest a bad electrolytic capacitor near the vertical amp IC. This is a low voltage issue. I'm not familiar with your model, but the vertical IC will probably be attached to a heatsink, and will probably have a part number beginning with AN, and be in a 9-pin (?) SIP package.

Follow the 4-wire lead back from the deflection coils on the picture tube. Two of the wires will go to the horizontal section (high voltage), and the other two will go to the vertical amp (~25V).

- Franc Zabkar

--
Please remove one 'i' from my address when replying by email.
Reply to
Franc Zabkar

It is a low voltage issue, but there are HIGH VOLTAGES in the vicinity.

The OP needs to either have had experience in this type of electronics (which it sounds like he does not) or at the very least, know enough to know what not to touch! Read, understand, and follow the SAFETY GUIDELINES in the TV Repair FAQ.

If in any doubt, get it repaired by a professional. This is not a major repair.

--
    sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/ 
 Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/ 
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm 
        | Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line.  Or, you can contact me via the Feedback Form in the FAQs.



> 
> - Franc Zabkar
> -- 
> Please remove one 'i' from my address when replying by email.
Reply to
Samuel M. Goldwasser

he

hich

t
e
r

tml

is

in the

.

Are there schematics avaiable online anywhere, free or purchase? Thanks for helo ALL

Reply to
bluespark

On Fri, 2 Apr 2010 05:23:08 -0700 (PDT), bluespark put finger to keyboard and composed:

Google turns up two suppliers for a service manual for a Panasonic CT27XF25CW.

FWIW, here is a parts list:

formatting link

Your vertical output IC appears to be a Sanyo LA7845N:

formatting link

There is an application diagram in the above datasheet.

- Franc Zabkar

--
Please remove one 'i' from my address when replying by email.
Reply to
Franc Zabkar

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.