XM702 Issues

bstnguy

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XM702 23" B&W Motorola Issues

Hi Group,

Looking for some direction working on a xm702 Motorola B&W.

Came out of a Boot Hill and showed vertical bars, full screen. (horizontal mounted monitor)

Did a Bob Roberts xm701 cap kit, installed into an Atari Football and now have two issues.

Screen is wicked shrunken. I can see the Xs and Os running around, but they are tiny.

And the image is 90 degrees off.

So, what would cause the image to shrink? (I try adjusting the Regulator pot and it just messes the focus up)

And can the image be rotated 90 degrees? (I know you can do this easily on a color WG raster by swapping yoke wires) and I haven't tied tube and chassis to common ground yet.

Thanks!
 

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You don't want to mess with the wires on the yoke to flip the image on this model. I have flipped the image a couple of times on the XM501 and I imagine it the same for the XM701. You do it at T3. if you look at the picture I've included, are your wires reversed? Gray on the left and green on the right if so swap those two wires so they look like the ones pictured. As for the shrunken picture I guess I'd start with double checking the caps you just put in and make sure there polarity is correct. What voltage are you seeing on Pin 2 it should be 73v.

Matt
 

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Thanks for the input!! The picture is 90 degrees off. so, is my yoke 90 degrees off? Can't tell if it's flipped yet (pic is too small) The monitor was originally a horizontal mount and now used vertically (Atari Football)

I will double check my cap kits and the B+ at P2.

Thanks!
 
If I remember right the boot hill image is reflected off a mirror so when you said rotated 90 degrees I figured you really meant reflected. You shouldn't have to rotate the yoke 90 degrees I guess someone could have done that but it shouldn't be like that. Is your yoke in the same position as the one in the photo above?
If you look in this Manual there are some flowcharts that may help. Page 24-25
 
The yoke on mine is the same as your photo. I can see the really small game screen. so not sure if it's the board or the monitor. I'm going to try and run a differnet signal into the monitor tonight and see if I can isolate. Flowchart, I tried adjusting the pot, but it just messed up the focus (and I tried the diametrically opposed one and it did the same). Also tried the size pots to no avail. I'll check out the other stuff tonight!

Thanks!
 
Update: Yoke is same position as Blinddogs photo. Is the yoke in the same position your football?

B+ is now at 73V, was a 68V, no change in image size.

Going to see if I can jump in another signal.
 
1) When you installed the 701 kit, did you verify the values matched what was on your 702?

2) Have you tried replacing your regulator?

3) Have you checked the voltage output of your horizontal and vertical amplification transistors?
 
blinddog: Your yoke in your football is the same as your photo?
Mode: 1. yes, need to double check though. 2. Not yet. 3. Nope, good suggestion also!

Thanks, I'll put up a posting when I've done some more work!
 
90 degrees off.

Before I start yoke fiddlin', want to make sure that how the monitors were changed from Horz to Vert use.
 
90 degrees off.

Before I start yoke fiddlin', want to make sure that how the monitors were changed from Horz to Vert use.

The swapping of wires mention previously in this post is for rotating the image 180 degrees. The only was to rotate an image 90 degrees is to rotate the yoke. It'll only take 30 seconds.

Edward
 
Gotcha, thanks for the input!! Once I get the image the right size, I can then figure out if I need to flip image.

Thanks!
 
Yes the yoke in my football is in the same position as the one in the photo. Post a pic of the screen as it is. then can you put a known good signal into the monitor and post a picture of it?
 
Wired in a DVD player and got the same thing. Looks like I duffed something during the cap kit. Time to yank it and review the values.

I'll post as I find stuff!
 
Update: ALMOST THERE!!!!

I was carefully removing the rear yoke wires (remember, they are almost blind) and I see "what's this big red dot...uh oh..."

Bust out a mirror and I completely messed up the Red and Green wire locations. There was a red spot on the other side (that's visible) of the yoke, so I had the yoke wired incorrectly. Lucky I didn't blow anything.

Only thing left is a mirrored image and that looks like a simple wire swap at T3.

To summarize:

Symptom: XM702 image shrunk and rotated 90 degrees (on following pic, Red on Empty lug, Green on Red lug, Black correct) . Video is visible in very small image (like 2" x 4"), image mirrored, once size fixed, image rotated 180 degrees

Solution: Confirm Red and Green wires are connected to proper connections (causes shrunked and rotated image, following pic correct Red and Green wire placement), T3 wires reversed (causes mirroring), rotated yoke 180 degrees (causes image to be 180 out)

I'll post a pic of the completed monitor!

Thanks all for suggestions and insite!
 
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Got the mirrored imag fixed by the T3 wire swap.

Only item remaining is the image is 180 degrees off. So before I start swapping around the yoke again, does moving the tap change the oriention? I'll snap a pic of my yoke and post it. If anyone with a Football can confirm the locations of the wires on theirs compared to mine, that'd be great!
 

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Nice to see it's getting close. Football is a really fun game. It's been on my must haves since the beginning.

I can't help you with a picture because my monitor is a m7000 but I noticed your yoke is 180 degrees off of what the yoke is in my first pic (it's from my Tank) so I'm thinking you'll have to rotate it. And for clarification the wire swap is done on T3 you been writing down P3
 
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