Goofy @*!$% Sanyo monitors (or is it me...)

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Archived from groups: rec.games.video.arcade.collecting (More info?)

I've been pretty lucky with cap-kits, but I've yet to make a Sanyo 20-EZV
respond to one. Here's a couple of samples from my latest attempt:

http://members.sparedollar.com/baudtender/sanyo-20ezv-1.jpg
http://members.sparedollar.com/baudtender/thumbs/75_sanyo-20ezv-2.jpg

This, of course is running a Playchoice board, you can see that there's
a green-ish translucent band running vertically on the left side of the
screen.

It happens, as you can see, on multiple games, and also with an entirely
different main pcb swapped in.

Any ideas what I should be looking at next?

Thanks in advance,
Scott

 

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baudtender1 .at. comcast.net wrote:

> I've been pretty lucky with cap-kits, but I've yet to make a Sanyo 20-EZV
> respond to one. Here's a couple of samples from my latest attempt:
>
> http://members.sparedollar.com/baudtender/sanyo-20ezv-1.jpg
> http://members.sparedollar.com/baudtender/thumbs/75_sanyo-20ezv-2.jpg
>
> This, of course is running a Playchoice board, you can see that there's
> a green-ish translucent band running vertically on the left side of the
> screen.
>
> It happens, as you can see, on multiple games, and also with an entirely
> different main pcb swapped in.
>
> Any ideas what I should be looking at next?
>
> Thanks in advance,
> Scott


Whoops, sorry - that second link should be:

http://members.sparedollar.com/baudtender/sanyo-20ezv-2.jpg

Scott

 

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Archived from groups: rec.games.video.arcade.collecting (More info?)

Keep in mind that there are several electrolytic caps that are not
included in the kit (such as c411 and C202). These monitors are now so
old that the capkit suppliers now should include those other caps as
part of the kit.

If your monitor has an inverter board attached to it there may be a bad
cap on it. The capkits do not include any caps for the inverter board.

Check resistor R478 (one ohm) to see if it's gone open.

Are you making up your own capkits with caps you buy yourself or are
you buying the prepackaged capkits from the usual suppliers? There are
several non-polar electrolytic caps on this chassis.

 

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Archived from groups: rec.games.video.arcade.collecting (More info?)

On 31 Jul 2005 22:39:49 -0700, "Ken Layton" <KLayton888@aol.com>
wrote:

>Keep in mind that there are several electrolytic caps that are not
>included in the kit (such as c411 and C202). These monitors are now so
>old that the capkit suppliers now should include those other caps as
>part of the kit.
>
>If your monitor has an inverter board attached to it there may be a bad
>cap on it. The capkits do not include any caps for the inverter board.
>
>Check resistor R478 (one ohm) to see if it's gone open.
>
>Are you making up your own capkits with caps you buy yourself or are
>you buying the prepackaged capkits from the usual suppliers? There are
>several non-polar electrolytic caps on this chassis.

Hey Ken,
Could you possibly write up a Fromm style flow chart for the Sanyo EZx
series monitor.
If you and Art put your heads together I bet you could knock one out.

Here is a tip you can add to it.
Problem: Screen was shifted to the right. Could not adjust it to
center. Here is a picture:
http://members.aol.com/dgoooch/SanyoProb.JPG

Solution: Replaced shorted mylar cap at C485 .047 100v

Theory: Written by RonKZ650 (A pinball guy, that owns a TV repair
shop, but doesn't own video games )
Problems like this are usually the feedback from the HV transformer
(flyback transformer), to the osc section is missing. So if it uses a
48 or 64 pin IC for the horiz/vert osc ect, usually there is one pin
that the flyback feeds back a pulse to to sync the horiz. There's
usually a couple of small capacitors and a couple resistors that
return this pulse to the IC chip, sometimes diodes too, and they can
short out and kill the pulse. Otherwise the centering can also be just
a control and a couple resistors that vary the DC voltage on the low
side of the horiz winding of the yoke, but I doubt this is the problem
because major centering problems such as yours are usually in the
feedback.


Dan in Denver

Click here for my current auctions
http://tinyurl.com/68o72

www.classicarcaderesource.com

 

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Archived from groups: rec.games.video.arcade.collecting (More info?)

I appreciate the help, Ken! These are cap kits I got from Bob Roberts
a couple of years ago, and you're right, it did not include all of the
caps on the main or inverter boards. I'll check that resistor today -
I guess it's time to break out the ESR meter and check the rest of the
caps. I bought that thing figuring it would be a "magic bullet" for
someone who's a software rather than a hardware guy, but I've yet to
have it pay it's worth (it did find a couple of marginal caps on a Galaga
pcb that had garbled sounds except for explosion, but replacing them
didn't do the trick.)

I guess I should get into the habit of putting the ESR meter on all
caps that aren't included in my cap kits. I've got two of these
Sanyo cap-kits left, and one Vs. dual that has both monitors with top
1/3 folded - guess I'll cross my fingers.

S.W.


Ken Layton wrote:
> Keep in mind that there are several electrolytic caps that are not
> included in the kit (such as c411 and C202). These monitors are now so
> old that the capkit suppliers now should include those other caps as
> part of the kit.
>
> If your monitor has an inverter board attached to it there may be a bad
> cap on it. The capkits do not include any caps for the inverter board.
>
> Check resistor R478 (one ohm) to see if it's gone open.
>
> Are you making up your own capkits with caps you buy yourself or are
> you buying the prepackaged capkits from the usual suppliers? There are
> several non-polar electrolytic caps on this chassis.
>

 

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Archived from groups: rec.games.video.arcade.collecting (More info?)

baudtender1 .at. comcast.net <"baudtender1 .at. comcast.net"> wrote:
: I appreciate the help, Ken! These are cap kits I got from Bob Roberts
: a couple of years ago, and you're right, it did not include all of the
: caps on the main or inverter boards. I'll check that resistor today -
: I guess it's time to break out the ESR meter and check the rest of the
: caps. I bought that thing figuring it would be a "magic bullet" for
: someone who's a software rather than a hardware guy, but I've yet to
: have it pay it's worth (it did find a couple of marginal caps on a Galaga
: pcb that had garbled sounds except for explosion, but replacing them
: didn't do the trick.)
:
: I guess I should get into the habit of putting the ESR meter on all
: caps that aren't included in my cap kits. I've got two of these
: Sanyo cap-kits left, and one Vs. dual that has both monitors with top
: 1/3 folded - guess I'll cross my fingers.

Cap kits are good for basic geometry issues (like the foldover on your
dual vs monitor), and help with some shutdowns, but they're far from a
silver bullet.

Color and sync and voltage regulation issues are just as likley to be
due to flakey transistors as bad caps. A cap kit is just an easy first
step in monitor repair, and keeps you from chasing stupid problems that
aren't related to expensive components.

--
Mark Spaeth mspaeth@mtl.mit.edu
50 Vassar St., #38.265 mspaeth@mit.edu
Cambridge, MA 02139
(617) 452-2354 http://rgvac.978.org/~mspaeth