Here's my 2cents worth on it!
hanatarex polo 25" monitor
was working fine and has been working fine in an extreme hunting
in sammy atomiswave cabinet.
monitor went dead. removed monitor, replaced all caps and reflowed all solder joints. mini fuse is ok.
still dead.
remove monitor again and replace flyback and H.O.T.
now, monitor comes on with vertical line in middle of screen.
whats next?
The Box caps are for the Horizontal retrace pulse..as well as other caps
are and safty in the output stage..to protect the circuit from hv getting to high.
when they go bad it effect the shaping of the pulse.. for hv and picture size.
and looses the drive current needed for the horizontal windings of the yoke.
and loose the width..
Its not uncommon to loose connections between parts in this chassis.
These models have a good picture when they work.
most people are trying to get around from restoring the chassis as if it should
last forever.
If this is your first and last repair you might send it out or replace it with
another whole tube and chassis and get away from that chassis.
But if you want to fix it right,get what you need to restore the chassis
and rebuilding the high voltage circuit is just as important as the powersupply..
these caps are not in every chassis in other brands so they aren't mention that much.
The values of the box caps are mark on them it a no brainer just replace them
as well as close inspection of the traces to the circuit.
there are a few thread at this site that may help in the repair..
Call the spec in to a parts company they will help you decide a good replacement.
Its just the type of caps they are just not a good lasting style caps used in the chassis
it was what the company was using at the time but these type of caps fail in all circuit
i'v seen and fixed many tvs that used these style caps and all of them fail
sometime a visual inspection is all you need to do.
if the box cap looks bulged or split and the belly of the cap has cracks
in it replace them all at the same time for best results..
From my 40 years experience in component level repair this chassis just needs
to be rebuilt correctly the first time..the vertical ic is also part of my capkit.
Connections to the ic is very important one good reason is because its mounted
to a very large heatsink so bad connection to the little pins is something to look for
as well.In some case's the vertical ic shorts theres no fusable resistor to it
and it will kill the powersupply.. so don't look for 10 good reason's to replace it
unless you have good troubleshooting skill's and can trace down a shorting part and
with no experience with this chassis.
I understand everybody wants a quick fix i do to!!
I would't waste my time or money replacing these parts if they weren't Bad.!!
Soldering the large watt cement resistor is very important too,if you have to use
jumper wires between aparts then do it..DO NOT use a Solder bead as a connection
use correct gauge wires to repair intermittent or open traces..all of the chassis
are dark around the areas because the heat is not being dissipated correctly because
of the bad or cold solder connection to the these parts..
its easy to find these aparts they are needed to drop the dc from the powersupply to the
Horizontal drive and output stage,thats why they are so big in size and wattage.
The location of caps is important when you remove them but not to find them you can tell by
just looking at the board.A good trick is to take a picture of the area so you don't get
confused where they were as you track them down.
When the problem become catastrophic it will open the damper diode as well.
Because the unbalance circuit it will snap the diode in half sometimes its open and still
touching in place causing the width and Hv to go wild..take out the HOT.
The flyback is needed after all these years they all work closely together..
If you still need 10 good reason's to replace all the parts the chassis needs
then this repair is not for you!!Good LUck!