Nanao MS8-26U B+ issue?

bluestreak

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This is in my Sega Daytona USA and I have recapped the complete monitor board except for 1 cap (c437- 120uf 50v) I could not locate locally easily.
Problem remains that the picture is skewed or stretched mainly noticable on the edges.
see pic and notice the Daytona words also near the right edge of screen.
I haven't searched for what the B+ voltage should be but could this be the issue or would it be some other adjustment?
 

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Anyone know what the B+ voltage should measure on this board ?


i had measured some test points after a cap kit
and it was 127v's.
I replaced C437 with a 100uf/50v's
when i worked on it..
Anybody misadjust the pots on the main board..
I have a chassis but no schematic.
I'll look the chassis over and get you some locations
of parts that may cause this.
Get the same picture with low and med res?
 
I went in tonight and just tried a few adjustments on the B+ setting but it didn't make a difference on the skewed pic.
Also tried adjusting most all of the Horz adjustments except the coil and even some of the vert adjustments, but no change.
Coincidently, I picked up the same cap you did for C437, but wasn't sure if a lower value uF would be OK so I didn't put that one in.
I haven't tried changing the resolution. Is that OK to do?
If so I'll try it just to see.
 
I went in tonight and just tried a few adjustments on the B+ setting but it didn't make a difference on the skewed pic.
Also tried adjusting most all of the Horz adjustments except the coil and even some of the vert adjustments, but no change.
Coincidently, I picked up the same cap you did for C437, but wasn't sure if a lower value uF would be OK so I didn't put that one in.
I haven't tried changing the resolution. Is that OK to do?
If so I'll try it just to see.

that cap is in the vertical ciruit,odds its not part of the problem.

Whats the B+ set at?? Measure @D904 cathode??
You can check another res if you like just for kicks
to see how the picture looks..
The game board may have a switch to change res..
or may need an external signal.
Might recheck all caps are solder in good.
 
I'm out of town for a few days but will check the actual B+ v when I get back Monday.
The caps should be good as I just replaced them all except that one I mentioned earlier.
The resolution change I believe is just a connection move on the board itself unless the neck board needs something done to it also. Don't know about that one.
 
Looks like B+ is high, that model use 105 volt, you should measure it at the fuse F902, I m posting the pdf, although I use to adjust to 90 volt, D1880 would turn too hot...
 
Finally got back to this one. Since I received suggestions on 2 measurement points, I measured on both.
At D904 Cathode side it was 325v AC and at Anode 63v DC
At F902 I couldn't get a DC volt reading as it appears it's over 1000v range of my meter. No AC voltage measured there.
BTW omarale, there was no PDF.
Any ideas?
 
anyone know where I can locate a schematic for this monitor board?

I got one i'll send over.
The B+ could be around 105 dc measured @f902
You may have the wrong ground,with those voltages
is your battery in your dvm good?
The B+ control should be glue remove glue and set voltage
in the 900 circuit near back edge of board marked B+ adj
Also for the skew Try adjusting the vertical trim pot marked PCSI
 
Battery is good in DVM. I did wonder about the ground. I was grounding off of the flyback shield.
I've already removed the glue from the B+ adjustment so good there.
I'll look for the vertical trim pot you suggested as well.
 
I didn´t realize I´ve ecxeeded the size allowed, I´ve resized and splitted to 2 jpg´s, hope it would help, regards
 

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Thanks, I haven't had time to get back to it with the holiday sgoing on but will next week.
Thanks a bunch for the drawings.
 
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