[TechAssist] Re: Panasonic CT27G12V with 3" vertical deflection
- From: "Gemini Computer & TV" <geminitv@xxxxxxxxxxxxxxxx>
- To: <techassist@xxxxxxxxxxxxx>
- Date: Sat, 6 Mar 2004 09:58:04 -0500
The set is fixed. The problem was MISSING R454 (47K surface mount) off pin 4
of IC451. What I did not know was after he resoldered the IC, it went from
no deflection to this partial deflection. He must have accidentally removed
it when resoldering the IC (it was an ugly resoldering job for a former
tech!). The pads were clean so there was no physical evidence of the
resistor missing. Thanks to all who sent scans and Jeff Stileau for leading
me to the service manual. Once I had these in my possession, I was able to
scope waveforms and found several were about half the amplitude and then
quickly found the resistor indicated in the schematic was not on the board.
Installing the resistor cured it!
Bob Waterman, CET® #RI-28
Master Technician License #9109
Service Manager / Parts Manager
Gemini Computer, TV, & Security Alarms
(508)695-7302
(508)695-7769 FAX
geminitv@xxxxxxxxxxxxxxxx
geminitv@xxxxxxx
www.geminicomputertvsecurityalarms.com
----- Original Message -----
From: "Gemini Computer & TV" <geminitv@xxxxxxxxxxxxxxxx>
To: "Techassist" <techassist@xxxxxxxxxxxxx>
Sent: Friday, March 05, 2004 8:37 AM
Subject: [TechAssist] Panasonic CT27G12V with 3" vertical deflection
> I have a Panasonic CT27G12V that belongs to my office manager's ex-husband
> that currently only has about 3" of vertical deflection. He used to be a
TV
> tech years ago and originally had intermittent vertical deflection so he
> resoldered the vertical IC which cured it. Now he brought it in with this
> problem. I am not an ASC for Panasonic so I have no service literature for
> it. I have replaced IC451 with an OEM LA7838 and capacitors C451, C452,
> C453, C454, C455, C459, and C551. VCC is at 27.8 volts to the IC. After
> replacing these parts, I still have the same symptom so I am asking you
> Panasonic experts for some advice here. I realize the yoke is a
possibility
> but I thought I would ask here first.
>
> Bob Waterman, CET® #RI-28
> Master Technician License #9109
> Service Manager / Parts Manager
> Gemini Computer, TV, & Security Alarms
> (508)695-7302
> (508)695-7769 FAX
> geminitv@xxxxxxxxxxxxxxxx
> geminitv@xxxxxxx
> www.geminicomputertvsecurityalarms.com
>
>
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