Hantarex MTC 9000 small picture and wrong colors

[pintris]

Hi all,

My Hantarex MTC 9000 was dead a few weeks ago. I replaced the flyback. After that, the monitor powered up again, however now my actual image is very small (only 30% of the total screen is covered.) Also, the colors are wrong. for example, the walls in pacman are green instead of blue. All 3 colors appear to be working, but they are just wrong.

I do have to say that I hooked up the wires from the flyback to the nec board wrong first. I soldered the focus wire to the screen wire and visa versa.. I don't know if that broke something else...

Attached a picture while playing MS PAcman. You can see that the display image is too small. Making it wider or taller with the knobs on the little pcb only stretches it but the image become unreadable.

Thanks for any help

Patrick

 

[gunblade]

what flyback model number did you use?
what is the b+ level?

 

[RGP]

Wonder if it's one of those 9000's with the colour inversion selector just behind contrast and it's got nudged.

 

[gunblade]

Wonder if it's one of those 9000's with the colour inversion selector just behind contrast and it's got nudged.

yeah or its a 10" mtc9000 chassis from a playchoice 10 on a 20" tube

 

[RGP]

Wonder if it's one of those 9000's with the colour inversion selector just behind contrast and it's got nudged.

yeah or its a 10" mtc9000 chassis from a playchoice 10 on a 20" tube

Polo 2 rgb wiring

If B+ was low it doesn't shrink the picture that bad does it? I've seen dim screen and a wavy line when b+ is down at 90v but not shrinkage like that.

It is as though deflection is ending at 50% drive in both directions

 

[pintris]

Hi,
Thanks for your replies. I did not touch the RGB wiring itself. The monitor did work fine first with normal picture size and colours. But all of a sudden it did not power up anymore so I changed the flyback. I used the flyback type HA28026031, which I ordered and I was assured this type was for the MTC 9000. It did fit properly. Only thing I did wrong first was that I switched the thick black and thin red wire wrong (so the "screen" wire ended up on the "focus" and visa versa)
Patrick

 

[tb2000]

If your chassis is a standard 19" mtc9000 european version then i'd say that's the wrong lopt. Your number cross references to HR7107 whereas you need a HR7025.

 

[pintris]

Hi tb2000,
The manual that was included with the arcade cabinet states it's a "Hantarex MTC-9000 19 & 25-inch Color Monitor(HR7107)" so according to that it should be correct.
Any visible indication on how to check the difference between a HR7107 and a HR7025 ?

Patrick

 

[silverfox0786]

The manual you should be using is the Hantarex MTC-9000 14, 16, 20 inch

 

[gunblade]

i think the problem is to do with the lopt itself,put in a hr7025 and i reckon it will be fine

 

[RGP]

Yes, as Gunblade will be able to explain better there are versions of the 9000 chassis that can be modified to run a 25" screen, I can't remember the exact changes but I have seen about 4 different versions of 9000/9110 chassis on both 19 and 25" screens.

My feeling is the wrong flyback model is now installed - although pin compatible, its not driving enough voltage into the tube to reach full width/height as drive, HV and size are all intertwined.

Having connected the focus/screen wires the wrong way around, i'm not sure of the implications here, i'd have to look at the schematics and I can't remember the voltages involved but both are higher voltage if I remember correctly.

Your colour issue looks like a different case though.

Can you post a picture of the chassis?

We also need a B+ reading.

Doesn't look like anything's been blown up.

 

[tb2000]

Hi tb2000,
The manual that was included with the arcade cabinet states it's a "Hantarex MTC-9000 19 & 25-inch Color Monitor(HR7107)" so according to that it should be correct.
Any visible indication on how to check the difference between a HR7107 and a HR7025 ?

Patrick

Yeah, it's odd that they state different lopts to be honest. Some manuals state one type some another type. You usually find that HR7107 fits the MTC9110 or the U.S. version of the 9000. A couple of years ago or so, I bought a batch of MTC9000 lopts from America but they were no good for chassis over here. Turns out they were equivalents of HR7107's from what we could work out. They didn't even fit properly - the lopt heatshield/sink needed to be modified - strange really as Chad at Arcade Cup has used loads of them with no problem. Even when fitted, they didn't do the job. I fitted one which was ok at first, then after a few minutes the colours went odd (bit like yours!) and then it burnt out a track underneath the chassis. On fixing the track and reinstalling the original HR7025, it worked fine. If you look at the HR7107 specs you'll find they are different on the voltages on a few pins. On the HR7107 it puts out something like 260v on one particular pin whereas on the same pin on the HR7025 it puts out 100v.

 

[pintris]

Hi guys, first of all, thanks for all your valuable feedback. I really appreciate it.
tb2000,

What you tell is indeed what I experienced when ordering the LOPT. I first ordered from a local guy and when it arrived (supposedly for the MTC 9000) it was much "deeper" than the original one. You can see in the picture below the original flyback and the "wrong" one that I got delivered, that did not fit into the case:

You can see the right (new) one had more space on the back and the screen and focus wires are mounted "above" the knobs, and therefore would not fit into the iron chassis casing. My chasis is like below (without the lopt mounted):

The second flyback I ordered did fit into the slot. It looked exactly the same as the old one. So that's why I imagined it would be the good one. But clearly it is not?

So question I have ofcourse is... what should I order now? The one I got from the local guy clearly did not fit. But if that appears to be the correct one after all, than should I cut out a part of the iron casing (the part you see at the bottom right of above picture?

B+ is 147VDC if I measured correctly. I measured this by putting the red meter probe into one of the two middle holes of the connector on the chassis end into which the scan coils (coils fitted around the neck of the tube) are plugged into, and the black meter probe to the metalwork of the chassis.

Thanks

Patrick

 

[RGP]

Your B+ is high for a 9000 - it should be around 130vDC at that point.

I usually use black lead to frame and red lead on SP4 (which is the right hand side brown wires coming down from the resistor).

This looks more like a modified 9000 to work on a 25" tube at 110degrees but i'll let people with more experience give a definitive answer.

 

[tb2000]

Ok so what size screen are you using then? It's for a 25" or 28" tube as James says. It's actually the MTC9110 chassis, which is a 9000 redesigned/modified by Hantarex to run 25"/28" tubes, hence the need for a fan over the lopt as it's putting out a higher HV level etc. Your replacement lopt should therefore be ok. With that said, you can run a HR7025 in these no problem. Have you got a pic of your replacement lopt? B+ should be 130v, at least according to the schematic. I thought these were higher but I may be thinking of the Polo chassis (138v for 25"/28"). To be honest, I would've thought the OCP/X-Ray circuit should've kicked in at that level, and even if it didn't, at 147v your picture should be much too big, not too small! I usually measure B+ the same way as you've done, red probe in the centre pin of the yoke connector, black to ground. Getting the focus and grid 2 wire round the wrong way may have damaged something but you can usually get away with it if you haven't run it for more than a few seconds. I think you get around 6 or 7kv up the focus wire, the grid 2 wire has something like 200v but i'm not sure about that.
tb20002015-01-03 16:59:36

 

[pintris]

Hi,
Attached a picture of the new lopt (left) and the old lopt (right).

With the old LOPT, the screen "clicks" every second or so... probably the xray circuit popping in each time and the screen would not power on.
With the new lopt, after powering on, the screen also often "clicks" once and does not power up (no crisping sound). So I guess also then the xray protection circuit actives before it can power on... I sometimes need to power on (and off) the screen two or three times before it works and stays on, be it with the tiny picture and wrong colors. When it's on, it usually stays on, except when I dial the vsync/hsync dials or the screen width or something on the small board. Than it usually goes off again also.

So it looks as if the xray protection indeed is triggering a lot, even with the new lopt...
It's a 25inch screen. I also noticed the fan mounted on top does not work.
Patrick

 

[tb2000]

Lopt looks ok but it seems like you have more than one problem. I would think you've got at least one polypropylene cap causing you problems. These are the rectangular ones behind the lopt. As an experiment, turn the h-sync pot all the way clockwise and see if it comes on straight away. Seems they've started labeling the lopts with HR model numbers rather than Hanty part numbers!