Build Your Own Arcade Controls Forum
Main => Monitor/Video Forum => Topic started by: perjmolsen on December 15, 2018, 06:36:49 pm
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Hi
Me again :)
While i am waiting for components for my other two monitor repairs - I am trying to find the reason for why my Hantarex MTC9110 is dead.
(Mounted in my table top)
I have tried to used what Grantspain and Princess prin prin has told me, but it seems that I still need the experts advice :)
Problem: No picture, and no raster when i turn up the flyback.
I have tested the following:
TP1= 23,89V OK
TP10 = 131,6V OK
SP4 connector at R105 is 130V
TP12 = 12V OK
TP13 =25V OK
TP14 = Only 162,4V - according to my manual is must be 200V
D15 tested OK in circut
C36 is tested OK (4508pf)
C34 is replaced
R216 on neck PCB is also tested OK out of circuit
TR15 (HOT) is tested OK out of circuit.
TR20 (SGSF441) tests OK out of circut
What i have changed:
Nearly all the electrolytic capacitors except C54 on man PCB
And the C205 (10uf 250V) at the neck board (tests as 10.86uf ESR=1.3 ohm vloss 0,7%) new caps are ordred
Re- flowed all pins on flyback
My next step is to try to leave hot out of circuit, and 40W lamp to pin 1 of flyback to see if its is the flyback (I guess that also is possible on this chassis?)
But what can cause my 200V only to be 162V? is it the last cap C205 on neck board..
Merry Christmas
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is the fan running?
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Hi
Yep the fan is running.
And i have made the light bulb test - connected to pin1 at flyback and it lights up, so rules that the flyback is not the issue?
(I have a new spare flyback if i need to try to change it)
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Do you have 6.3VAC on pins 9 and 10 of the CRT socket?
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Do you have 6.3VAC on pins 9 and 10 of the CRT socket?
Hi
Wil try to test - but need to be sure to do it right :)
I guess that chassis is ground?
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The pins marked F. One is ground so you can use any ground like the big heat sink.
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Hi
I now have tested, and it is to low
Pin 9 = 1,415V AC
Pin 10= 0,010V AC
So is it the flyback? or what proof this test ? ??? :D
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You said the resistor is good but try on the other side too.
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You said the resistor is good but try on the other side too.
Hi
I have now measured the volt at R126
At the side near to flyback : 166,3V at the other end 167,4V
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But one side of R216 (the side closer to the CRT socket) is the same as pin 9 of the CRT socket and you said earlier it was 1.4VAC. Now you're saying it's 166V?? Is that DC voltage? If you send that kind of voltage to pin 9 (assuming R216 is OK) you will blow the filament in the tube. Is the filament OK (very low resistance across pins 9 and 10)? That 166V (assuming it's DC) is suspiciously close to the too low RGB amp voltage you're getting. Is the flyback a HR7107? In that model the heater voltage and the RGB amp voltage windings are connected together so an internal short could send 166V through the heater output pin of the flyback but it's difficult to diagnose this fault without checking things personally. The flyback is suspect at this point. Personally I would check if it's good with a flyback tester:
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HI
Oh i might have measured wrong then.
Just to clarify :)
When i tested volt at the CRT socket pin9 and pin10 i had set my meter to AC volt not DC. (I will test again and with DC volt)
When i tested R126 i tested i DC - i thought i where that resistor :)
I will also test the DC volt at both ends at R216 at the neck board and let you know the results
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Hmm..
Just pulled out the R216 again.. messure 2.2ohm
And now i am confused about the right value, according to my eyes the colors are
BROWN-GREEN-GOLD-GOLD then 1.5 ohm 1W metal oxide resistor
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The heater voltage is AC. it comes off pin 6 of the flyback and goes to the CRT socket with just a resistor (R216) in series. The is no rectifying diode like on other outputs so it's AC not DC. If you don't have an AC voltage of about 6-7V at either side of R216 I would say the flyback is bad.
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The heater resistor forthe 9110 should be 0.5 ohm (green/black/silver) or 0.51 ohm (green/brown/silver). You have 1.5 ohm (brown/green/gold). It's possible that your meter adds 0.7 ohm (touch the leads together and see). I would say it's good. Not sure why the different value, probably for a different tube.
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Hi
I have removed the flyback - and yes I think that it is dead.
The flyback I had where an HR7191 so not for this chassis, but for a Hantarex polo.
I have ordred a new HR7107 - I where unable to find any numbers on the old one.
Thanks again for the super help! :cheers:
I will keep you updated when I get the new flyback :)
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Hi
Just an update -
My home-build table top now play with picture :applaud:
It where a dead flyback, a new HR7107 where mounted, and there where picture
Thanks again for all the help Grantspain and Princess prin prin
I owe you one or two ;D
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is this a 19" or 25" crt?
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Hi
It is a 25" CRT
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A picture of sticker on chassis
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that is good then