[SOLVED] Hantarex MTC 9110 - Width issues

[mawrick]

I'v just replaced flyback transformer and a recap, fired it up successfully (I guess cabinet/monitor haven't been working for 15-20 years) so never seen it running myself.

The 130V seem to be ok (The monitor is powered via a step down transformer so 110V (where it should be 128V), but afaik this should be ok (seen other running with this voltage), but can't seem to get the width to fully expand.

I did adjust the coil on the picture as I thought it was the coil for adjusting width, but it's the coil for horizontal linearity. Later found out it might be related to what hantarex names a "bridge coil", but trying to adjust this one it seem stuck, and it started to crumble when trying to move it, so just gave up on that.

Seem to be able to adjust things from the remoteboard and the pincushon board, but not to the full width of the monitor

Is there any known replacements for those bridge coils that is available today, or maybe other chasis that have these exact coils ?.

If anyone have any available it might be of interest, also if there is any other tips on how to sort this issue it woulf be appreciated.

The game used for testing is a vertical shooter so orientation is wrong on the game on the pics

 

[ner38073]

Besides the remote board nobs, is there another pot on the chassis to adjust the horizontal size limit? Look for it and turn it down or close it. You should see a reaction on the width.

 

[mawrick]

Besides the remote board nobs, is there another pot on the chassis to adjust the horizontal size limit? Look for it and turn it down or close it. You should see a reaction on the width.

Don't think there is any more pots to adjust in regards to this matter afaik, so guess I'l have to look into other things...

 

[ner38073]

Then do a reflow on the solder joints of the entire horizontal section and the remote board. If that does not work then replace the horizontal pot.

 

[mawrick]

I'v done a complete replacement of pots to no avail, had it up and running, but still not able to get full width, tried to change out the C37 to a total value of 0.68 (misread and thought that was value for 25", but turns out it's for 28"), however this caused the monitor to not power up again, and even after changing back to the original values I'm unable to get it up and running, had the TR15 and TR20 out of circuit and they seem to measure ok.

Have now hooked it up doing a lightbulb test, and get these numbers:

input from hantarex us 250: 134.4V DC
SP4 (Left side of resistor): 104.4
SP3 (Right side of resistor): 133,2
Output of pin 3 (from left side if you look from the resistor side) of the yoke connector: 106,6v


the tr20 have:
1 (b): 108,2v
2 (c): 133,1v
3 (e): 107,7v


Any sugestions would be appreciated

 

[mawrick]

Got it back up and running again, the lightbulb test seem to have "failed" due to to low voltage from the Hantarex us 250 when it gave in 134.4V, hooking up a 110V ac transformer made it come up with somewhat correct voltages, however the main "culprit" was propably a stray soldering "blob" that was sitting underside the board

However I'v now added another cap in paralell and have about 0.463mfd on the C37 cap, but still having trouble with my width.

Anyone know if the IC 2 might cause these troubles as well ?., nothing apparent wrong with it, but iirc I'v seen someone had trouble with to much width caused by some errors in this chip (but not 100% positive i remember this correctly).

 

[mawrick]

Just thought I'd give a final update on this if anyone else experience this problem in the future.

Finaly was able to sort out the issue and turns out it was due to a short between the legs of C405 on the pincuchon board, still some adjustments to do but seem to be fully working now