The NEW Build Your Own Arcade Controls
Main => Monitor/Video Forum => Topic started by: perjmolsen on November 19, 2019, 04:25:32 am
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Hi
I got this Hantarex Polo/2 25-28 that is dead, so I am trying to repair it.
I have successful repair Hantarex Polo's, but newer a Polo/2, so I need some basic help with this one.
There is no ticking sound, completly dead.
I have tested the fuse, that is good.
Testtet OL from HOT middle leg to chassis.
I have no schematic for Hantarex Polo2, and it does not seem that the normal testpoints as in the Polo are present.
1. How do I connect the 40W bulb to test the B+ power supply? What do I need to lift?
2. Where do I test the normal volts? and what should they read?
3. If my PSU volts are OK, can I still de-solder leg3 on flyback to see if it the flyback is dead
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It seems tthat the PSU is putting out power
R32 = 23V
L6 = 15V
Tested the diodes after the PSU:
D6
D10
D11
D16
D44
D47
All where OK
I have tested the poly caps around the flyback:
C103
C99
C97
C96
They tested all ok
I traced the b+ from the 100uf 250V cap at the psu, If I do that I get all the way to flyback PIN3 with connectivity.
So I tried to de-solder the leg from pin3 and connect the bulb to pin3 . Then I got light, and 145V :dizzy:
So I went back to test the 25V at R153, now i only see 8V and tested 16V at L6 there I now only have 0V :hissy:
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Your second to last picture is confusing as you sucked solder off pin 1 not 3. Pin 3 is the b+ and 1 is the other end of the primary winding of the flyback that connects to the HOT collector. To test the b+ you need to suck solder off pin 3 (the correct one) and connect the bulb to the pad or something directly connected to the pad like R153 (as in the last pic) or more simply you leave the flyback alone and lift that side of R153 and connect the bulb to it.
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Hi
Have found out why my volts where low on R32 and L6.......... :hissy:
My battery in my multimeter where low on power!!! :banghead:
Put in a new 9V battery - and tested
R32 = 23V
L6 = 15V
And B+ messured at R153 = 145V
So all my volts are OK. :applaud:
Next step is try to put in a new flyback (HR7191), and see if I still have B+ because if i solder pin1 and pin3 at the current flyback, then my B+ is 0V
And the HOT is good, so it must be the flyback...there is no visual defects at the current flyback.
And one last thing.. how do I open the connector?
I have tried to pull and press on the tabs, but no luck
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Check if the primary and secondary windings are shorted. 1-3-4 must be isolated from 5-6-8-9-10:
http://www.hrdiemen.com/reparation/flyback/scheme/7191
Check if pin 1 on the chassis (with flyback off circuit) is shorted to ground. You said the HOT and the high voltage caps are good but the damper diodes may not be. If you remove the HOT and bridge pin 1 and 3 on the chassis and the bulb lights up and b+ voltage is present there are no shorts (but HV caps/diodes may be open).
That socket is the worst type without a release mech. I would suggest to replace it. I can give you a free one if you pay for the shipping.
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Hi
I have now put in a new flyback, and my +B at is way high 195V-200V
If I remove solder at pin3 at flyback, and put on a bulb, I get 145V B+
If i follow the Hantarex polo flowcart, it says to replace C114 (in my case I assume that is C18 it is at the same spot)
I have replaced the cap, but the B+ is still high with the flyback in place.
So the next step, is to test B+ at the collector T114 (in my case T22) its is also high.
Then I have tested for 12V at pin1 on IC104 (in my case IC6) there i only have 1.3V
So it seems that my 12V is missing, so where do I check for 12V an my Hantarex Polo/2 chassis - the normal Polo is TP10 - but no TP at my Polo/2
It would be so wonderful if I had a schematic over a Hantarex Polo/2, so that i could find the components on the 12V line
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Your B+ is spot on so the power supply is fine and it makes no sense to replace parts there.
The problem is something in the horizontal drive circuit (starts at pin 4 of the TDA2595 and ends at pin 4 of the flyback) is not working as it should so the flyback does not work or it shuts off immediately because of the x-ray protection. Most likely some component connected to the HOT collector line is faulty or there's a crack in that area or the solder joints are bad.
Don't use the Polo schematics for reference as that chassis has different parts. The IC that generates the H drive pulse on the Polo is a TDA2593 but on the POLO 2 it's a 2595. Different pinout so your 12v check was pointless. The Polo 2 schematics you can find with google are of the automatic frequency switch version but most things are the same.
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Also, to use a 7191 flyback on this chassis you need to change the jumpers as shown here:
http://www.ukvac.com/forum/forum_posts.asp?TID=368371&KW=&PID=1120284&title=the-new-hr-diemen-flyback-transformers#1120284
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polo 2 auto schems
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Hi Grant and Princess prin prin
Thanks for all you help :cheers: :notworthy:
I have tried to see if I can figure out why my B+ is so high (185-190V) when the fly is mounted.
I have 12V at D12 (12V on the striped end and 11V at the other end) so my 12V is present.
I have tested D12 out of circuit, it tests fine.
Pulled out t15, t16 , t17 and t18 and tested them, they all test fine.
Found a bad trace at IC5 (TDA2595) - fixed it but still the same high B+
:hissy:
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you should check the poly hv caps
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also put the track back how it was for the time being- i will check one of my chassis tomorrow to see if it has the same mod
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Hi
I have tested all the poly caps around the fly - they tested OK - even also replaced them with some new, but still B+ is 185-190V
I have removed the jumper at the track :)
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you replaced the flyback?
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Yes I have tried to put the original flyback back (HR7191), but still the same issue, stil high B+
So it is not the flyback...
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check th2, should be about 1 ohm one side and 20 ohms the other
chech tr20
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Hi Grant :notworthy:
I have looked almost everywhere but I can not find TR20... :hissy: :hissy:
I can fin T20... is that the component?
When i test TH2 i get 25ohm at one side and1 ohm at the other side, tested in circuit.
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yeah t20, switching for the horizontal drive transformer
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Hi
Tested the T20 (BF419) tests OK in my tester.
Also tested T19 (bdx53a) tests also OK in my tester.
I have also tested that the TDA2595 gets 12V at pin 15, it get 11.4V
What do i overlook.. :banghead: I do not understand why my B+ is so high when fly is in, and fine when i test with a bulb as load... :dizzy:
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HUSTON.... WE HAVE FOUND THE PROBLEM :applaud:
I THINK we have a dead resistor...
R156 an 2K2J 7W resistor is OL!
It do not think that I have a 2.2k ohm 7w resistor in my parts boxes.. hmm
Would this 2 ohm 10W resistor be a good replacment?
https://www.aliexpress.com/item/32863720936.html?spm=a2g0o.productlist.0.0.655a55e4LU9R0u&algo_pvid=e40acf40-22f1-41dc-be27-c5a418ebfb45&algo_expid=e40acf40-22f1-41dc-be27-c5a418ebfb45-50&btsid=6440fef2-fdfc-4509-ac91-3d4323bd4548&ws_ab_test=searchweb0_0,searchweb201602_6,searchweb201603_53
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yes that would do it
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Take it from a Polo for a quick test.
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when i meant that would do it i meant the fault not the replacement resistor you sent the link for- you want a 2.2k same wattage
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Hi
An update
I have now replaced the R156 2.2 7W resistor with a new one.
Now my B+ is steady at 145V :applaud:
And there is also picture, not a good one yet, but after I had turned the monitor on for about 10-15 sek, something blow up. :cry:
It where the BY228 at D44 - It got really hot and blew up, I have changed it with a new one, and after 10 sek. "on-time", I can feel that it is getting hot and I tun the monitor off, so that it does not blow one more time.
What can cause the BY228 diode to get so hot and blow up? :notworthy:
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Recap your power supply circuit, if you have not done it yet
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Recap your power supply circuit, if you have not done it yet
But my PSU volts are all OK when i use a 40W bulb as a test load?
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I am not saying that recapping the chassis will 100% solve your issue, but you will have a better starting point going on with the troublreshoot. Leaking caps give all sort of bad behaviour and after 30-40 years it's good practice to replace electrolitics.
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Hi :cheers:
Started looking at this chassis again, trying to figure out why BY228 at D44 gets hot, and I why my picture looks like the one below, (the picture is a bit dimmer than the photo below, camera adds a bit light to the photo)
I am unable to adjust the picture better than what you see.
I have changed the following caps, but it did not change anything
c17 220uf 50v
c18 22uf 50v
c25 22uf 50v
c31 470uf 35v
c32 220uf 25v
c106 47uf 250v
c92 4.7uf 250v
c11 100uf 250v
C9 150uf 400v
C87 1uf 100v
C88 4.7uf 100v
Tested
D44 by228
D47 BYW95C
C99 8.2 NF
C97 .33J 250
C96 4.7 NF
My B+ is 145V
I am thinking, that I might had put in the wrong flyback HR7191, even that the old one where a HR7191
A Hantarex polo/2 this chassis is a dural sync right?
So a HR7375 flyback is the correct flyback for this chassis right?
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polo 2 auto or polo 2 15?
polo 2 auto is hr7375
polo 2 15k is hr7191
how do you tell, does it have the switching pcb in the power supply section
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polo 2 auto or polo 2 15?
polo 2 auto is hr7375
polo 2 15k is hr7191
how do you tell, does it have the switching pcb in the power supply section
HI :cheers:
Hmm...switching pcb in the PSU... :o
The PSU part look like this :notworthy:
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hr7191 is required
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hr7191 is required
Ok thanks :cheers:
I just tried another HR7191, the same issue, so ruled out the flyback.
Thinking the next step is to change the last electrolytic caps...it might be a bad cap, and its an easy fix if it is, and it may need a cap kit anyway
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or you need to adjust the horizontal hold pot or horizontal shitft
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or you need to adjust the horizontal hold pot or horizontal shitft
Tried to adjust the pots, I am unable to get the picture better.
I noticed that the H.AMP and KEYSTONE does nothing at all...
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look at all the diodes in the horizontal circuit
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look at all the diodes in the horizontal circuit
Hi Grant
Do you know where D31 is on the chassis.. I am unable to find it :dizzy:
I have checked D27,D28 D38 and they are fine
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check the width transistor
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check the width transistor
It is the T19 right the bdx53a? - its tests also good
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just checked a polo 2 28 15khz chassis here
C101 3.3NF 1600V
C86 4.7K 250V
C99 8.2NF 1600V
C97 .33 250V
D44 BY288
D47 BYV95C
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just checked a polo 2 28 15khz chassis here
C101 3.3NF 1600V
C86 4.7K 250V
C99 8.2NF 1600V
C97 .33 250V
D44 BY288
D47 BYV95C
Well I have found the issue... its my fault :banghead:
C97 - I had put in a 333J cap, it should be a .33 cap.
Changed it, and now the picture looks better :applaud:
But the picture is to wide and I am unable to adjust it.
So I am thinking that the C96 is the issue.
Currently I have a 472J cap in.
If I change it to a 4.7uf the picture is to small....
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So I am thinking that the C96 is the issue.
Currently I have a 472J cap in.
If I change it to a 4.7uf the picture is to small....
Why did you change the value from 4.7uF which is correct to 0.0047uF (that's what 472 is)??
If you can't adjust width and you have a pincushion distortion it's because the correction signal from T19 is either missing or it doesn't arrive at the diodes. I'm wondering if the bridge/width coil is the problem. Or R135.
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Hi
THANKS! ;D :notworthy:
It where R137 that where dead! :cheers:
Put in a new 10 ohm resistor, and now I am able to adjust picture :applaud:
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I don't work much on these later POLOs and I didn't notice there was a resistor in series with the EW signal until I looked at the schematics last night. Earlier Hantarex chassis don't have it.
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I don't work much on these later POLOs and I didn't notice there was a resistor in series with the EW signal until I looked at the schematics last night. Earlier Hantarex chassis don't have it.
Still I am amazed of you and grantspain :notworthy: