[TechAssist] Re: Zenith PV4661 Projection TV

  • From: "David Lessard" <mrfixit@xxxxxxxxxxx>
  • To: <techassist@xxxxxxxxxxxxx>
  • Date: Mon, 13 Jan 2003 22:40:51 -0500

Thanks for the information Jeff. Eventually I will find a schematic
and this TV will be out the door. If you have any more tips, don't
be shy, share your thoughts, anyone else!. David.

-----Original Message-----
From: techassist-bounce@xxxxxxxxxxxxx
[mailto:techassist-bounce@xxxxxxxxxxxxx]On Behalf Of Jeff Dougherty
Sent: Sunday, January 12, 2003 10:53 PM
To: techassist@xxxxxxxxxxxxx
Subject: [TechAssist] Re: Zenith PV4661 Projection TV



David,
I understand that, hence why I said I don't think your problem is in the
vertical.
I provided that information for future reference when working on projection
sets.
support@xxxxxxxxxxxxxxxxxx
FAX 717-564-4952
Jeff Dougherty
Intrepid Video & Electronics      Be careful of your thoughts.
501 Luther Rd                        They may become your words
Harrisburg, PA 17111                            any moment.
717-909-8844
VCR tips, electronics info & general interest.
www.intrepid-video.com www.tech-repair.net
www.thetoolcaddy.com www.9-11-2001tragedy.com
***********************************************************************

----- Original Message -----
From: "David Lessard" <mrfixit@xxxxxxxxxxx>
To: <techassist@xxxxxxxxxxxxx>
Sent: Monday, January 13, 2003 8:26 AM
Subject: [TechAssist] Re: Zenith PV4661 Projection TV



Jeff,

The flyback fires up but only for a second (therefore it's not possible to
turn up G2). The (3) tubes flicker during the attempted startup, then shut
down occurs. Turning the TV off then on produces the same result. The two
resistors you mention near the flyback are related to video problems (this
is what I was told), not a shutdown problem. Something is preventing the TV
from firing up properly but what?  What I need is more information, ie.
schematics. Here are the module numbers for this TV. I would like to start
debugging the vertical deflection circuit first, this seems the most likely
cause for a shutdown problem because the vertical +B is flyback derived.
Thanks. David.

convergence PS         - 9-553-01
video output           - 9-625-01
SMPS                   - 9-628
sweep                  - 9-629
A/V selector           - 9-660
low level registration - 9-666
registration           - 9-667
video interface        - 9-678
main module            - 9-700
IF audio               - 9-701
RF selector            - 9-702
audio PS               - 9-764
audio AMP              - 9-765-01
high voltage           - 9-815



-----Original Message-----
From: techassist-bounce@xxxxxxxxxxxxx
[mailto:techassist-bounce@xxxxxxxxxxxxx]On Behalf Of Jeff Dougherty
Sent: Saturday, January 11, 2003 9:18 PM
To: techassist@xxxxxxxxxxxxx
Subject: [TechAssist] Re: Zenith PV4661 Projection TV



David,
I don't think it is the vertical circuit, now. With projection sets, if you
have a vertical problem, the symptoms are usually the same as a direct view,
except you see no horizontal line. Projections sets are designed to blank
the
video so as to not burn the line on the screen. To determine if the problem
is in the vertical section, you need to increase the G-2 just slightly. If
you see the horizontal line appear, quickly turn the G2 back down.

You will get more assistance if you also include the module number in your
posts.
On Zenith..the small signal and convergence module numbers usually need to
be
posted.

You have two resistors near the HOT, I believe...check those. One is 82, the
other
110k, I believe. Also, since you have OSD..your vertical would not be the
problem.

support@xxxxxxxxxxxxxxxxxx
FAX 717-564-4952
Jeff Dougherty
Intrepid Video & Electronics      Be careful of your thoughts.
501 Luther Rd                      They may become your words
Harrisburg, PA 17111                        any moment.
717-909-8844
VCR tips, electronics info & general interest.
www.intrepid-video.com www.tech-repair.net
www.thetoolcaddy.com www.9-11-2001tragedy.com
***********************************************************************

----- Original Message -----
From: "David Lessard" <mrfixit@xxxxxxxxxxx>
To: <techassist@xxxxxxxxxxxxx>
Sent: Sunday, January 12, 2003 4:15 AM
Subject: [TechAssist] Re: Zenith PV4661 Projection TV



FOLLOWUP: I just got back from checking out this TV in person. Symptom
details: TV plugged in, SMPS fires up, press "ON" button, Front PWR LED is
lit, HV starts but only for a second (crackling heard), just long enough to
see tubes flicker, you can hear audio amp power-up (speaker click is heard),
Front PWR LED remains lit. Before all these problems started the customer
said the TV would come on but with no video, only OSG and audio worked
(eventually the video worked but shutdown occurs within 30 minutes). What
can cause a shutdown? The audio amp board has a seperate PS, it's not
flyback supplied. What about the vertical circuit as Jeff suggested? I need
a service manual (schematics) please, anyone? Thanks gentlemen.

David Lessard
Alexandria Electronics
50 Harrison Street
Alexandria, Ontario
K0C-1A0
(613)525-4502
mrfixit@xxxxxxxxxxx

-----Original Message-----
From: techassist-bounce@xxxxxxxxxxxxx
[mailto:techassist-bounce@xxxxxxxxxxxxx]On Behalf Of Jeff Dougherty
Sent: Friday, January 03, 2003 4:38 PM
To: techassist@xxxxxxxxxxxxx
Subject: [TechAssist] Re: Zenith PV4661 Projection TV

David,
Troubleshoot your vertical circuit.
I have a feeling there may not have been OSD before..maybe customer was
mistaken.

support@xxxxxxxxxxxxxxxxxx
FAX 717-564-4952
Jeff Dougherty
Intrepid Video & Electronics      Be careful of your thoughts.
501 Luther Rd                        They may become your words
Harrisburg, PA 17111                            any moment.
717-909-8844
VCR tips, electronics info & general interest.
www.intrepid-video.com www.tech-repair.net
www.thetoolcaddy.com www.9-11-2001tragedy.com
***********************************************************************

----- Original Message -----
From: "David Lessard" <mrfixit@xxxxxxxxxxx>
To: <techassist@xxxxxxxxxxxxx>
Sent: Friday, January 03, 2003 12:40 PM
Subject: [TechAssist] Re: Zenith PV4661 Projection TV

Hi Larry, Module I need is 9-815 however this is no longer available from
Tristate. Flyback hasn't been made since 1997. Also, new problem, client
turned on TV last night to double check the symptoms and now this is whats
going on. Sound comes on right away, there is a horizontal red/green line
visible for a split second, no menu visisble now, there was before, the
sound is OK and obviously the flyback is working. Being half alive I'm sure
I could fix this beast however I have resources on it what so ever, if
ANYONE has schematics please let me know, I would like to study the circuit
before heading over the customer.

Thanks.

-----Original Message-----
From: techassist-bounce@xxxxxxxxxxxxx
[mailto:techassist-bounce@xxxxxxxxxxxxx]On Behalf Of Larry E.
Sent: Friday, January 03, 2003 9:26 AM
To: techassist@xxxxxxxxxxxxx
Subject: [TechAssist] Re: Zenith PV4661 Projection TV

David, Don`t have the print so I don`t know the module # you can call
Tri-State and they`ll look it up for you and give you a price, yes there
is a dud charge but Tri-State will also sell it to you outright, there
# is 800-203-7484.
Larry Eastman
American TV & Electronics
Crystal River, Fl.

David Lessard wrote:

> You don't happen to know what module I need? Is it the whole chassis? I
> know nothing about this projection TV and because of this I believe it
> may be more practical to purchase and swap (is there credit for a dud?).
> Thanks again.
>
> David Lessard
> mrfixit@xxxxxxxxxxx
>
> -----Original Message-----
> From: techassist-bounce@xxxxxxxxxxxxx
> [mailto:techassist-bounce@xxxxxxxxxxxxx]On Behalf Of Larry E.
> Sent: Thursday, January 02, 2003 8:53 PM
> To: techassist@xxxxxxxxxxxxx
> Subject: [TechAssist] Re: Zenith PV4661 Projection TV
>
> Dave, regular 1/2 watt resistors mounted on the top, just a real pain to
> see it where it`s located,mine was a PV4665, but I`m pretty sure they
> are the same, from the back of the set look at the right corner of the
> HOT heatsink and you should be able to see R3244 the 82K, the R3243 is
> usually on the other side of the heatsink next to R3244, Remember that
> you can always swap the module if it gets too involved, available at
> Tri-State module. I usually spend 1 hour troubleshooting a Zenith
> Bigscreen to component level, after that I just swap the module, good
> luck Dave, Larry E
>
>> David Lessard wrote:
>>
>>Larry, Thanks for the tips, another couple of questions, are these
>>resistors surface mount of through hole? Just wondering what to bring
>>to the customers house. Is this TV hard to get into? I would like to
>>appear at least semi-intelligent when I open it up, :-)
>>
>>David Lessard
>>mrfixit@xxxxxxxxxxx
>>
>>-----Original Message-----
>>From: techassist-bounce@xxxxxxxxxxxxx
>>[mailto:techassist-bounce@xxxxxxxxxxxxx]On Behalf Of Larry E.
>>Sent: Thursday, January 02, 2003 8:24 PM
>>To: techassist@xxxxxxxxxxxxx
>>Subject: [TechAssist] Re: Zenith PV4661 Projection TV
>>
>>Dave, did you check/replace R3243 110K 1/2 watt? have to pull one leg to
>>check it, goes way up in value and sometimes opens. Note that it`s
>>VERY difficult to find, it`s located by the HOT heatsink usually on the
>>right side,behind the heatsink, once you find R3244 (82K) your close
>>they are in series with each other, have seen several of them cause your
>>problem, also causes convergence problems, ie, no video with 3 bowed
>>bars, 1 red, 1 blue, 1 green, Hope this takes care of it for you,
>>Larry Eastman
>>American TV & Electronics
>>Crystal River, Fl. 34428
>>www.tvjunkyard.com
>>
>>>David Lessard wrote:
>>>
>>>Ed, Yeah I thought about the filament voltage at first but it doesnt
>>>make sense that the menu is still present after the picture goes out.
>>>So its only the video that dissappears, what caps are most likely to
>>>cause this problem?
>>>
>>>Are they surface mount? I have no information on this chassis, can you
>>>help out? Diagrams, schematics, tips, anything...Thanks a bunch Ed.
>>>
>>>David Lessard
>>>Alexandria Electronics
>>>mrfixit@xxxxxxxxxxx
>>>
>>>-----Original Message-----
>>>From: techassist-bounce@xxxxxxxxxxxxx
>>>[mailto:techassist-bounce@xxxxxxxxxxxxx]On Behalf Of Tel-Tek Electronics
>>>Sent: Thursday, January 02, 2003 4:54 PM
>>>To: techassist@xxxxxxxxxxxxx
>>>Subject: [TechAssist] Re: Zenith PV4661 Projection TV
>>>
>>>David;
>>>This is the C8S chassis. Without seeing it, hard to say, but sounds like
>>>probably a bad connection on the board for the Filament voltage. Unless
>>>it's only the Video that dissapears, then you got some bad Caps to
>>>contend with in the Video circuit.
>>>
>>>-Ed-
>>>>----- Original Message -----
>>>>From: "David Lessard" <mrfixit@xxxxxxxxxxx>
>>>>To: <techassist@xxxxxxxxxxxxx>
>>>>Sent: Thursday, January 02, 2003 4:08 PM
>>>>Subject: [TechAssist] Zenith PV4661 Projection TV
>>>>
>>>>Hi techs,
>>>>
>>>>Has anyone ever heard of this model before? Google search turns up
>>>>nothing. Customer describes the problem being a slow picture start
>>>>(2-5 minutes - gradually) however OSG menu is visible before picture
>>>>starts to come in, then after 30 minutes picture goes black again,
>>>>shut down and cool off period required before trying again. Not sure
>>>>if OSG menu is still visable at this point, forgot to ask, I will
>>>>follow up on this. Any help would be appreciate.
>>>>
>>>>Thanks.
>>>>
>>>>"Share what you know, Learn what you don't"
>>>>
>>>>David Lessard
>>>>Alexandria Electronics
>>>>50 Harrison Street
>>>>Alexandria, Ontario
>>>>K0C-1A0
>>>>mrfixit@xxxxxxxxxxx
>>>>
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