Sanyo20EZ B+ Adjustment video, fixed the droops

[Lutus]

I am inching ever so closely to finishing up my donkey kong restoration.

Sideart and this monitor issue are the only things left.

On to the fun……


The bottom left corner of the screen seems to “sag” lower than the rest of the screen.  It is also somewhat wavy.  The sag starts in the center of the oil barrel on the first screen and goes to the left edge of the screen.  It also goes as high as the girder right above the barrel.  The rest of the screen looks great.

A recap of things done so far.

Monitor cap kit (not including HOT, or flyback), audio board repair cap kit, DK board from Mike’s Arcade, and redressed the video/power signals in all kinds of configurations with no change.

I will upload a picture of the sagging tonight after work, but was wondering if anyone had seen this issue before.

 


EDIT:  The cap kit was the one without the additional 9 chassis caps.  This wouldn't be it would it?

[Lutus]

Found a guy with a similar problem on some other forums. 

Supposed answer...... drumroll......

Adjust horizontal hold, which on a Sanyo, is a trim pot on the chassis that you have to use a screwdriver to get to.  It is not on the adjustment board.

DOH!   

I will update tonight if that fixes my issue.  Hopefully so.

[Lutus]

 

The horizontal hold did not fix it.

Below is a pic of the problem.

If the power line runs near the yoke RGB wires, would that cause this?


Also, I added a little teaser of the whole cab.

I routed out the top of the control panel to add the Nintendo joystick onto the repro CP.

[Lutus]

Youtube vid

You can see the far left side of the first girder past the oil barrel is drooping down. And it kind of undulates at the oil barrel.

[youtube]http://www.youtube.com/watch?v=TwlYtLb7ad4[/youtube]

[qrz]

looks like pwr supply ripple . check caps in the regulator circuitry.  not a bad idea to check 'em in the vert out  and  h/v osc stages too.   ( i.e. the here popular "cap kit")

as for the yoke question .  current flow in a wire produces a electromagnetic field.
since the yoke operates on the same principal , any strong external magnetic field will have an effect on yoke .
a color crt is more sensitive to magnetic field . hence the need for auto degaussing circits
"Gauss" is a measure of magnetic strength.

qrz

[Ken Layton]

Replace the other caps that were not in the kit and the main filter cap too.

[Lutus]

qrz, I will check those

ken, I will replace those

thanks, will have to order those, but will get them

what is a source for the main filter capacitor? bob roberts?

this thing does have an original flyback transformer in it.  should I change that?

[The_Tyler_Black]

Youtube vid

HORRIBLE MISTAKE!!

[Lutus]

Update pics. 

That's all.

Haven't ordered the new caps yet.  also, showing the current state of my "gameroom"

[Lutus]

I have installed the second upgrade cap kit thing and a new filter capacitor.

The drooping problem is NOT gone AND a new problem has risen.  The video appears to be pulsing.  What I mean by that is that it looks like the picture zooms in and then out a little bit, around twice a second.

I pulled the chassis back out and checked all the caps orientation.  They are all just the silkscreen dictates, which SHOULD be exactly like the previous caps were since I only replace 1 at a time.

Is the Sanyo silkscreen all correct or are there any caps that are marked backwards?

Anyone seen this problem before?

[Lutus]

Forgot to say that the 300mA fuse had been replaced by a 1A fuse at some point in time in this things life.

I am picking up some 300mA fuses today to replace with before I fire it back up, but wanted to point it out, in case something may have been cooked.

[Bender]

I am having an issue similar to first issue on this thread with my DK cab as well
The left side of the screen sags a little at the bottom
and when I start it up the whole left side droops severely like 2 inches down on that side. After it warms up a little (maybe 5 minutes) it's not to bad
definitely playable but I'd love to fix it
Any Ideas?

[Lutus]

FIXED!!!

My B+ voltage was reading +88V.  Holy crap is that low.  It should be around 108V.

I adjusted my monitor to be 108.4V, adjusted all my colors and now the pic fills the screen and the droops are GONE!

Thanks to all who helped.  The monitor now looks AWESOME.  Now onto actually setting that record.   

[Bender]

Lutus,

could you explain how you tested and adjusted the the voltage
sorry to sound so stupid but what is B+ voltage?

I Think that might help me too

Thanks,

Bender

[Lutus]

I've looked for 20 minutes for a clear photo of the dang 20EZ chassis but can't find one that shows what I want.

I will take a photo of my setup when I get home today.

Basically this is what you end up doing. 

I have a multimeter lead that is a small hook/prong thing and I connected it to the TP91 (it is right above the large white ceramic resistor near the horizontal width coil).  the other black probe I connected to the chassis ground.

Turn on the machine with your meter set to 200VDC.  Mine showed +88V at this point.

Turn up the "BRIGHTNESS" control setting on the little daughter control board to the maximum.

Now, take your TV tuning tool that is taped to a straw and adjust the B+ voltage potentiometer on the board until your meter reads +108V.

You will hear different frequency "whines" coming from the monitor as you adjust the B+ voltage.  I believe this is normal.

I had a high pitched whine at +108.0V so I adjusted mine to +108.4V and it went away.

After you adjust your B+ you WILL have to adjust all your other settings.

Again, I will post some pictures.  It is not dangerous IF you take the right precautions.


Yes, I believe this will help you out bender.  From now on, as soon as I do a cap kit I will inspect that B+ voltage first thing.

[Lutus]

The B+ voltage is your rectified DC output from the rectifier that converts your AC input into DC voltage.

At least that what I think it is right now.  I am on some medication right now because I have a staph infection in my leg from Jiu-Jitsu.   

[Lutus]

Well I got the video recorded BUT the camera ran out of battery while importing it so I will have to postpone it a little on posting it.

[Bender]

Thanks so much Lutus

I'll try it out in a few days
I did a cap kit a while back and that fixed most of the problems I was having , except the sagging
I'll post to let you know how it went

Thanks Again,

Bender

[Lutus]

I got the video uploaded FINALLY.  Took a couple of HOURS.




Not a bad tutorial.  Applies to all monitors you just have to find the right B+ test point and B+ adjustment knob.

Hope this is what you were looking for.

 

[Level42]

Nice vid.

You really need to buy one of these:


I put it off for way too long but they are worth every cent when working on cabs

[Lutus]

HAHAHAHA, you are so right.  Next time I am at walmart or something I will buy one of those.