Magnavox Convergence

T

TimeRanger

Guest
New to the group, so forgive me if this has been covered before.

'The Patient: Late 80s model Magnavox rear projection unit. Except for
the list below, the unit is in excellent condition.

The Problem: Green seems to be too low and the blue is WAY too far to
the left. If I adjust the red to its lowest point, it *just* lines up
with the green. The blue however is another story...I have NO
horizontal (left/right) adjustment and minimal vertical (up/down)
adjustment. Although I may gain some improvement in the left/right
travel after I replace 2 toasted resistors on the board, I doubt that
it will be enough.

Is there a way to physically move the blue and green CRTS/guns a bit??
I just cannot find any type of adjustment for this problem - The
CRT/coupler/lens assembly appears to be securely bolted to a bracket
that is spot-welded to the mounting rails. Any assistance/advice that
Y\'all can give will be greatly appreciated.

(Due to the age of the unit, I don\'t think that it would be worth
taking to a "pro". In fact, the 3 shops that I called all refused to
"waste their time" on such an "antique", or wanted $200 up-front to
look at it.

Thanks
~Randy
Las Vegas

The Probability Of Someone Watching You Is Directly Proportional To The Stupidity Of Your Actions
 
The STKs are bad on the convergence board.




"TimeRanger" <Private@here.com> wrote in message
news:8ms920ha8p8v0gq03rbon0s6pge04tqaog@4ax.com...
New to the group, so forgive me if this has been covered before.

'The Patient: Late 80s model Magnavox rear projection unit. Except for
the list below, the unit is in excellent condition.

The Problem: Green seems to be too low and the blue is WAY too far to
the left. If I adjust the red to its lowest point, it *just* lines up
with the green. The blue however is another story...I have NO
horizontal (left/right) adjustment and minimal vertical (up/down)
adjustment. Although I may gain some improvement in the left/right
travel after I replace 2 toasted resistors on the board, I doubt that
it will be enough.

Is there a way to physically move the blue and green CRTS/guns a bit??
I just cannot find any type of adjustment for this problem - The
CRT/coupler/lens assembly appears to be securely bolted to a bracket
that is spot-welded to the mounting rails. Any assistance/advice that
Y\'all can give will be greatly appreciated.

(Due to the age of the unit, I don\'t think that it would be worth
taking to a "pro". In fact, the 3 shops that I called all refused to
"waste their time" on such an "antique", or wanted $200 up-front to
look at it.

Thanks
~Randy
Las Vegas

The Probability Of Someone Watching You Is Directly Proportional To The
Stupidity Of Your Actions
Click to expand...
 
OK, Its been a while - LONG while since I've done any electronic work
on a regular basis - about 10 years ago, I spent several years as a
slot machine tech - but even then, I did very little monitor work.
Mostly the processor boards. Question: What are "STKs" and are/would
they be readily obtainable from a supplier like *KIESUB* ? (
www.kiesub.com ) As I stated before, there are 2 resistors toasted on
the board, right near the connector that leads to the blue CRT. This
is the board that has a kajillion pots on it.

Thanks again,
~Randy

On Sat, 07 Feb 2004 16:54:16 GMT, "Mike" <temp@temp.com> wrote:

The STKs are bad on the convergence board.




"TimeRanger" <Private@here.com> wrote in message
news:8ms920ha8p8v0gq03rbon0s6pge04tqaog@4ax.com...
New to the group, so forgive me if this has been covered before.

'The Patient: Late 80s model Magnavox rear projection unit. Except for
the list below, the unit is in excellent condition.

The Problem: Green seems to be too low and the blue is WAY too far to
the left. If I adjust the red to its lowest point, it *just* lines up
with the green. The blue however is another story...I have NO
horizontal (left/right) adjustment and minimal vertical (up/down)
adjustment. Although I may gain some improvement in the left/right
travel after I replace 2 toasted resistors on the board, I doubt that
it will be enough.

Is there a way to physically move the blue and green CRTS/guns a bit??
I just cannot find any type of adjustment for this problem - The
CRT/coupler/lens assembly appears to be securely bolted to a bracket
that is spot-welded to the mounting rails. Any assistance/advice that
Y\'all can give will be greatly appreciated.

(Due to the age of the unit, I don\'t think that it would be worth
taking to a "pro". In fact, the 3 shops that I called all refused to
"waste their time" on such an "antique", or wanted $200 up-front to
look at it.

Thanks
~Randy
Las Vegas

The Probability Of Someone Watching You Is Directly Proportional To The
Stupidity Of Your Actions
Click to expand...
--
The Probability Of Someone Watching You Is Directly Proportional To The Stupidity Of Your Actions
 
yea, i know.


The kajilion pots are on the convergence board.

The convergence board also has big heatsinks on it, and the chips on the
heatsinks need replacing.

Sounds like your not a qualified television technician, so take it in to a
professional with the proper test equipment that can handle this.

BTW, the STKs mean that if you remove the brakets to the heatsinks, the chip
will have a number that starts with STK....

You can find these at mcmelectronics. very reasonable prices.



"TimeRanger" <Private@here.com> wrote in message
news:g3aa20p8kms28agr4r5snghls02r9dvip5@4ax.com...
OK, Its been a while - LONG while since I've done any electronic work
on a regular basis - about 10 years ago, I spent several years as a
slot machine tech - but even then, I did very little monitor work.
Mostly the processor boards. Question: What are "STKs" and are/would
they be readily obtainable from a supplier like *KIESUB* ? (
www.kiesub.com ) As I stated before, there are 2 resistors toasted on
the board, right near the connector that leads to the blue CRT. This
is the board that has a kajillion pots on it.

Thanks again,
~Randy

On Sat, 07 Feb 2004 16:54:16 GMT, "Mike" <temp@temp.com> wrote:

The STKs are bad on the convergence board.




"TimeRanger" <Private@here.com> wrote in message
news:8ms920ha8p8v0gq03rbon0s6pge04tqaog@4ax.com...
New to the group, so forgive me if this has been covered before.

'The Patient: Late 80s model Magnavox rear projection unit. Except for
the list below, the unit is in excellent condition.

The Problem: Green seems to be too low and the blue is WAY too far to
the left. If I adjust the red to its lowest point, it *just* lines up
with the green. The blue however is another story...I have NO
horizontal (left/right) adjustment and minimal vertical (up/down)
adjustment. Although I may gain some improvement in the left/right
travel after I replace 2 toasted resistors on the board, I doubt that
it will be enough.

Is there a way to physically move the blue and green CRTS/guns a bit??
I just cannot find any type of adjustment for this problem - The
CRT/coupler/lens assembly appears to be securely bolted to a bracket
that is spot-welded to the mounting rails. Any assistance/advice that
Y\'all can give will be greatly appreciated.

(Due to the age of the unit, I don\'t think that it would be worth
taking to a "pro". In fact, the 3 shops that I called all refused to
"waste their time" on such an "antique", or wanted $200 up-front to
look at it.

Thanks
~Randy
Las Vegas

The Probability Of Someone Watching You Is Directly Proportional To The
Stupidity Of Your Actions


--
The Probability Of Someone Watching You Is Directly Proportional To The
Stupidity Of Your Actions
Click to expand...
 
In addition, I would recommend checking the condition of the coolant in the
projection assemblies, considering the age of the RPTV. They may be on the
murky side at this time. - Reinhart
 
Subject: Re: Magnavox Convergence
From: "Mike" temp@temp.com
Date: 2/7/04 8:54 AM Pacific Standard Time
Message-id: <YK8Vb.13010$cc.89@fe3.columbus.rr.com

The STKs are bad on the convergence board.
Click to expand...
Magnavox's of the late 80s use discrete semis, not STKs.

To TimeRanger: You can't physically move the CRTs. There are trim magnets
which can move the whole image for each tube, but doing so to compensate for a
defective convergence circuit and running the adjustments to hide this maneuver
will cause even more damage. If you don't have the understanding for these
circuits, you are much better off having it repaired properly.

John Del
Wolcott, CT

"I'm just trying to get into heaven, I'm not running for Jesus!"
Homer Simpson

(remove S for email reply)
 
The large heat sinks on the convergence board are all equally warm ( +
or - 3 degrees of each other, as measured with a quality infrared
thermometer).

I appreciate the responses, but the cost of having a "Professional"
exceeds the value of the set - for me anyway...Especially since I
obtained the set for the cost of hauling it out of a long forgotten
family room, and I plan on donating it to my newlywed daughter - IF I
can do the work for Cheap!

I know enough that damage can result from improper adjustment of the
pole magnets, and yoke clamp. Also, I am very aware of the hazards
associated with some of the voltages that are present, and I have what
I consider a nice collection of insulated/non-conductive tools that I
have gathered as the need arose.







On 08 Feb 2004 01:54:06 GMT, ohger1s@aol.com (John Del) wrote:

Subject: Re: Magnavox Convergence
From: "Mike" temp@temp.com
Date: 2/7/04 8:54 AM Pacific Standard Time
Message-id: <YK8Vb.13010$cc.89@fe3.columbus.rr.com

The STKs are bad on the convergence board.


Magnavox's of the late 80s use discrete semis, not STKs.

To TimeRanger: You can't physically move the CRTs. There are trim magnets
which can move the whole image for each tube, but doing so to compensate for a
defective convergence circuit and running the adjustments to hide this maneuver
will cause even more damage. If you don't have the understanding for these
circuits, you are much better off having it repaired properly.

John Del
Wolcott, CT

"I'm just trying to get into heaven, I'm not running for Jesus!"
Homer Simpson

(remove S for email reply)
Click to expand...
--
The Probability Of Someone Watching You Is Directly Proportional To The Stupidity Of Your Actions
 
check for bad solder connections, make sure all plugs are in tight; having done
that, rotate the yoke rings on the out of range CRT until centered; at this
point, you got nothing to lose...
 
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