PTV780 Phillips # 7P6051 NO Picture HV?

[kw]

Hi,

I have a Philips 60" 7P6051 chassis PTV780 with No picture. Sound and
volume work. Green power on led does light. The channels will change. I
have worked for about 11 years as an Electronics Technician in an Automotive
Engineering Lab. I have 0 TV experience.

I did purchase the cd manual from Philips 7566. I have schematics and some
ts tips. I have also read most of the HV related posts here. I have a
Fluke DVM and an O-scope.

I have the chassis loose. I wanted to remove the Large Signal board but I
have Know idea how to remove the HV lines. I am not even sure if they are
discharged. My screen is completely black. The CRTs do not light up at
all. It looks like the HV (Q902) emitter resistor R934 is open. Should be
0.33 ohms and it is about 2.4 ohms. I haven't checked any of the power
supplies yet.


Thanks
Keith
Redford MI area
camaros@ix.netcom.com

 

[Ol' Duffer]

In article <iuVvb.17725$Wy4.14801@newsread2.news.atl.earthlink.net>,
nospam@ix.netcom.com says...

I have a Philips 60" 7P6051 chassis PTV780 with No picture. Sound and
volume work.
snip
I have the chassis loose. I wanted to remove the Large Signal board but I
have Know idea how to remove the HV lines. I am not even sure if they are
discharged.

Bleeder resistor is integral, so you don't have to worry about
discharge if it has been off a few minutes. HV wires plug in
with snap-in plastic clips. First slide back the boot so you
can get at the connection. Then observe two slots on each side
of the receptacle. Take a pair of needle-nose pliers and mash
hard on the clip snaps through the slots. Then brace your thumb
against the flyback or splitter, pull hard and wiggle. Focus
wire is similar but even more difficult. Don't feel like a
failure if you break one or more of the clips, it happens some
of the time even with practice. Replacement flyback should
come with new clips, unless Philips has gotten stupid again.

It looks like the HV (Q902) emitter resistor R934 is open. Should be
0.33 ohms and it is about 2.4 ohms. I haven't checked any of the power
supplies yet.

Blown emitter resistor (and shorted transistor) usually means
bad flyback transformer.