Build Your Own Arcade Controls Forum
Main => Monitor/Video Forum => Topic started by: jhaberthur on November 20, 2013, 10:22:30 pm
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I have a Kortek SF 2001 or is it a K1-2-VO as indicated on Bob Roberts monitor identification page?
In either event, It's in beautiful condition and installed in a Ms. Pacman Cab. The color is great, the alignment is nearly complete, I just can't seem to shrink the horizontal width down enough to get into the display area. I'd say I've got about 10% overscan on the width and it has just killed the high score and extra lives display.
After attempting to adjust the coil I found a cracked ferrite core. I couldn't find the stock replacement so I went with a wells-gardner from a horizontal width cab after reading the musings of Ken and what do you know but it worked! So I'm currently able to adjust from 120% percent overscan to 110% (guessing at these percentages). The kicker of all this... I live in Reno, NV, a city away from KORTEK USA in Sparks, NV and they don't support this board.
So I need to recap the board right? Sure... that's what bobrobert's page said.. but that's a bit past my ability.
I'd be plenty grateful if somebody could help identify which cap needs replacing, and what resistance I should change it to. I've included some clear pictures and have limited access to the board as it's at a friends house across town.
Thanks in advance,
James
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jhaberthur
post to rickn
he is a nick here
do it pm he will answer u
ed
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Fair' nuff. Thanks for the quick reply. I'll give it a go.
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Well no reply as of yet. Other ideas ?
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did you change the entire coil or just the core?
old korteks used to suffer from horizontal size issues due to the 50v 47uf cap near the flyback
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I repleced the entire coil. What would I replace this50v 47uf cap with to address this issue?
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i do not know if that coil from a wells would be correct,not likely
that chassis looks brand new so possibility of cap failure is low
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Yes the guy I bought the cabinet from told me it was a new monitor. I looked all over for an exact replacement but man the parts just aren't around. Maybe itit's not the original but it does work to adjust the h width. I'm just fishing for a functional workaround
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the problem is if the coil has a different inductance,it will not give you the correct adjustments
in any case i think you may have a size jumper on that chassis-i can seen a header connector on it-if you do have this it should be marked N and W
this is located just above the deflection coil connector-its a red wire with a single grey connector
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Ok I'll check it out tomorrow if i can. The only single wire jumper i see is the red wire with the grey connector (hard to see maybe I32?) that hooks up in the center of he board right next to C213.
I'm not seeing a N or W label. do i just unhook the jumper and check it out? I'm a bit foggy on the advice here.
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oh its there
n=normal
w=wide
bet it is set to n=normal giving u under width
replace the cap also
there cheap enough
ed
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Oh on the board connected to the deflection coil. Only thing I didn't grab pictures of. Ok thanks for the advice, ill give it a shot this week when I can make a trip cross town. Thanks!
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i can see it clear as a bell
u see where the yoke hook's up ?
forward or reverse ?
that little jumper u c is the with jumper
ed
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Sorry for the delayed response... I do not always check the forums.
Pls understand we are not Kortek but more than happy to help! If anyone has a schematic, I will be happy to take a look.
Rickn
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Thanks for all the ideas! I'll be trying my hand at implementing these changes tonight.
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The jumper indicated was set on the W header. I changed it to the other one labeled S2 and that did bring the screen in a bit. So Thanks for that tip.
Unfortunately I feel that I have the wrong resistance on the replacement coil as it is still presenting with width overscan.
Soooo I'm at this:
1. Should i recap and change the resistance?
2. Should I attack the coil and try to find out a workable replacement as the original is seriously nowhere to be found.
3. Should I buy a new board and say to Hades with this whole operation?
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hmm i do not know enough about this chassis to be sure but i hope someone else may give an opinion on this
what happens if you leave that wire link disconnected?
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jhaberthur
no you are getting it
u might need to tweak a few things
if u are running mame ? then try 15khz s/w
if not running it native to the machine?
we can re-time the horz frq >we go easy here<
but it can be done
ed
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If i leave the jumper connection undone then i get a narrower screen (step in the right direction! thanks team!)
If i leave the jumper connection on W, i get a really wide screen (how it was hooked up)
If i leave the jumper connection on S2, i get the exact same as if it were undone.
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Also, to clarify: I am not running Mame.
I am running an original Pacman board that has been converted to a Ms. Pac.
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right i believe the jumper is meant to be left off to give a narrow screen,it makes sense as the other header is not marked as would be expected
i think your size coil may be a little out of spec,is there no way you can refit the original coil and find a ferrite core that will fit
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You know I was thinking that... If there was a denser core that i could fit into the one I have now.
Additionally I could refit the original if I had a new core. I don't believe I messed up the threads, but the core is still locked in the old coil.
Where can i get a new ferrite core?
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in this situation i grab one off a scrap chassis but i guess you do not have this luxury
i would imagine this chassis is just an upgraded version of the ktn or ktm-f chassis,maybe worthwhile looking for a non worker cheap on ebay
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http://www.ebay.co.uk/itm/Kortek-KI-2-VO-ARCADE-MONITOR-CHASSIS-Good-Condition-Complete-but-Untested-/221251240672?pt=LH_DefaultDomain_0&hash=item33839a02e0 (http://www.ebay.co.uk/itm/Kortek-KI-2-VO-ARCADE-MONITOR-CHASSIS-Good-Condition-Complete-but-Untested-/221251240672?pt=LH_DefaultDomain_0&hash=item33839a02e0)
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Yup I'm looking at that one. Its a fair price too. Sure 40 seems steep for just a coil but I'm willing. Unfortunately I have a sneaking suspicion that this coil still wouldn't fix it. Its a replacement monitor setup and I fear it never was dialrd in properly.
In any event I emailed that listing owner to check on the condition of the coil on that board.
Thanks all for your help and ideas. I very much appreciate it.
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now we are getting some where
>replacement<
here is what u need to do
dial in the horz freq to the yoke.
do u see the 2 red caps right in front of the yoke connector ?
these are your :tunning: caps :ie they set the yoke freq and timming:.
they should be high voltage type
by that i mean 600+ volts,and ploy style
them are the 1's we tweak
ed
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I checked out the ratings of the two caps in the picture that are nearest the jumper lead. The longer one at location c412 read 472 J S 1600V NPPS 910 MEPP. The other at lcoation c413reads 152 J S 1600V NPPS906 mepp
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I checked out the ratings of the two caps in the picture that are nearest the jumper lead. The longer one at location c412 read 472 J S 1600V NPPS 910 MEPP. The other at lcoation c413reads 152 J S 1600V NPPS906 mepp
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yup thats them
1600v
they tie the horz output to the yoke
+tune it at the same time
u can adjust there value by a bit
and by a bit i mean less then a mf >micro-fraud<
let me see what u can do
give me a day with them
values
ed
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Thanks ed!
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ya they look like .0047
and .0015
they are saftey caps
if u go to far out of range u will snap the neck of the tube off
can u read the horz winding restinace for me?
altleast it will give me a starting point.
maybe rickn will chime in now ?
as he knows tunning values backwards
ed
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Alright... how would I read the horizontal winding resistance? And go slow on this one.
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if u have meter ? digital ?
red and brown wires should be the horz side
green/blue should be vert
are these your yoke colors ?
to the plug ?
or do they differ ?
if u need i will refer back to your pic's u up-loaded
ed
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I've got access to a few multimeters. Ill get back into this project by midweek next thursday.