25" Hantarex Polo Troubleshooting

SterlingRush

Well-known member
Joined
Feb 20, 2010
Messages
3,738
Reaction score
162
Location
Bremen, Georgia
So I got this Street Fighter II Championship Edition from a friend, it fires up but plays blind. Last night I recapped it and replaced the flyback in the 25" Hantarex Polo, and I'm still getting nothing on the screen. I should mention before I did anything with the monitor, I powered it on to see what it did or didn't do. There was no glow in the neck before hand, and after the replacements, still getting nothing. Not getting power to the monitor maybe? I'm not hearing anything signifying that the monitor is trying to do anything. Also, didn't notice anything burnt or bad solder points on the board while recapping. I'm at a loss on what to try next.
 
horizontal output transistor is probably bad. Polos are assholes in that if the HOT goes, it takes the flyback with it ... or was it vice versa? if you listen hard enough you'll probably hear some faint ticking from the power supply trying to "start" the monitor.

some brave souls have worked on these on here, give it time and hopefully they'll respond.
 
Thanks Mech, I'll have to do some research on that horizontal output. These things must be gremlins, I don't seem to find a lot of good comments regarding them, lol.
 
I just had one blow out on me after a cap kit and a new fly. I burn tested it and it was fine. Put it in the machine for the guy. He played it for two hours, it worked fine. He called me the next day saying he played it for another hour and the monitor went out. I checked it and it was completely dead, fuse was good though. No sign of life at all. Pulled it, checked the HOT and it was shorted. I replaced it with the newer type (BU508AF) and crossed my fingers. Luckily it didn't take the fly with it. Has a great pic now and the new HOT barely gets warm.
 
Cold solder?

The few Polos I've worked on had bad solder joints. Like there were whole sections that had broken down. I'm not sure if reflowing is part of your capping process, but it helps. Reflow the power and video connections (and check the HOT!).

The ones I was lucky enough to get my hands on were lousy with the bad joints.
 
So I got this Street Fighter II Championship Edition from a friend, it fires up but plays blind. Last night I recapped it and replaced the flyback in the 25" Hantarex Polo, and I'm still getting nothing on the screen. I should mention before I did anything with the monitor, I powered it on to see what it did or didn't do. There was no glow in the neck before hand, and after the replacements, still getting nothing. Not getting power to the monitor maybe? I'm not hearing anything signifying that the monitor is trying to do anything. Also, didn't notice anything burnt or bad solder points on the board while recapping. I'm at a loss on what to try next.

You might check the voltages on Ic1 UC3842
if no secondary voltages from power supply.

check some chassis test points
for shorts or any voltages
and the hot T22 for a short
if power suppy is good.
And good connections.
Even touching the part on top of chassis and looking at the connection
on the bottom may show it has a bad connection, more common
with larger watt resistors loosing connection to the PCB.
 
I think there should probably be a sticky for the Polo as well. :)

use what Ohmerone says. along with that better HOT. etc.
 
I think there should probably be a sticky for the Polo as well. :)

use what Ohmerone says. along with that better HOT. etc.

No lie about the sticky, I'm seeing more threads pop up regarding these things. I had time to replace the hot with the BU508AF version, rechecked solder points, and tried to fire it up. Still nothing, no neck glow, I'm still not hearing any slight ticking, although the ps fan may be preventing me from hearing it. After that, I just put it aside as frustration was getting to me, better to walk away for a bit vs. throwing it against the wall, lol.

When I get more time, I'll attempt the other recommendations mentioned, although I'm like Dorthy walking through Oz right now. This is the most in depth I've been with a monitor and using a meter, so I'm trying to find someone willing to show me and walk me through what I need to do. Not exactly holding my hand, but I believe I'm over thinking what I'm looking at or for.

I do want to beat this monitor at it's own game, if they really are that bad, then even better for experience. If I can do this one, don't think others will scare me as much, lol.

And since I haven't said it yet, thank you all for the help and ideas, it is greatly appreciated.
 
I think if the HOT dies on these, the flyback goes too. I could be wrong.

there's a test you can do with like a lamp, to decipher if the problem is in the PS section or beyond that in the chassis, I forget how though.
 
I think if the HOT dies on these, the flyback goes too. I could be wrong.

there's a test you can do with like a lamp, to decipher if the problem is in the PS section or beyond that in the chassis, I forget how though.


Yea, I remember reading about that in another thread recently.

I might have found the guilty part, but I need other eyes to take a look, as I've never seen a burned part on a board before. Maybe it is, maybe it's just a lot of grime built up. Also, if it helps, I've taken pics for the rest of this, so if you have any questions about a part or location, let me know as this will be on the table for a bit.

And then a side question, where the heck is the IC101? I've come across that while reading, and for the life of me I cannot find it.

Pics, because unfortunately it did happen :(

CIMG1825.jpg


CIMG1822.jpg


CIMG1824.jpg


CIMG1819.jpg
 
You will have to test that ceramic resistor to see if its still good. The resistance value is listed on it, and you need to test it out of circuit (remove it, then test).

I spot 2 ICs on the chassis. Id guess that the one towards the middle would be 101, not positive though.

There is also one on the neck board.
 

Attachments

  • polo.jpg
    polo.jpg
    82.2 KB · Views: 49
If you suspect that resistor to be bad just ohm it out. It should be 2.2K ohms or 2,200 Ohms (same thing) The dark surface is heat discoloration. Check the solder joints on it too. The discoloration happens over the years though and is very common.
 
I generally don't necro threads, but considering one of my Polo's took a shit last week, and the fuse mysteriously is still good on it despite it glowing bright orange and murdering the line fuse in my KI2 cab, I could use as much like field stories about this as possible. lol

the knucklefuck that capped my chassis last apparently installed some caps in it backwards, so it looks like my first plan of attack is re-capping it. then I'll start pulling the block resistors, HOT, etc. to see if they check out. I'm going to guesstimate the flyback is toast. we'll see.

so what happened with you? lol
 
You will have to test that ceramic resistor to see if its still good. The resistance value is listed on it, and you need to test it out of circuit (remove it, then test).

I spot 2 ICs on the chassis. Id guess that the one towards the middle would be 101, not positive though.

There is also one on the neck board.

I see 4 Ics...in the picture!!
anyway Ic101 is the uc3842 PWM
loc in the primary of the power supply
if you have all your secondary voltages then don't worry about IC101..
Let us know if you don't know where the Test point are
coming out of the power supply..
Any secondary voltages means the primary in power supply is working!!

The B+ is shared by the HOT/transformer and Horz driver transformer those
two large resistor are used to drop the voltage to the two transfomers
they just need good connections to the pcb..
The schematic may not match up just mention the TP you test..
Good Luck!
 
Anyone ever experience an abundance of red on their polo? Picture looks nice and sharp..... However it looks like the red has been jacked up, ive tried turning it back, as well as turning back the red cut off...... And it goes from, dark red, to bright red...... Is this typically a kneck board issue, or a chassis issue? And what would be my first method of attack to fixing this piece of shit...
 
I see 4 Ics...in the picture!!
anyway Ic101 is the uc3842 PWM
loc in the primary of the power supply
if you have all your secondary voltages then don't worry about IC101..
Let us know if you don't know where the Test point are
coming out of the power supply..
Any secondary voltages means the primary in power supply is working!!

The B+ is shared by the HOT/transformer and Horz driver transformer those
two large resistor are used to drop the voltage to the two transfomers
they just need good connections to the pcb..
The schematic may not match up just mention the TP you test..
Good Luck!

I think I may have a power-related issue, not sure, but for fun, what/where are the test points? I haven't torn mine apart yet.
 
The left side of chassis
is the SMPS the Output voltages
exit there and go to the right and can be tested at
the very front of chassis on the top of the PCB in front of cage near middle..
there are small holes SP that would have the B+ and smaller voltages
from the power supply.
Do you have the paper schematic?
I wouldn't TS the circuit without replacing the caps first!!
After I check the HOT for a short!
Working with these i would pull the whole monitor remove chassis, remove on side
of Crt u bracket left side,position the crt with just one u bracket on the bench
and reinstall the chassis hook up yoke signal cable Etc.
To test after repairs. Theres a few parts the may be need to restore the chassis.
You can also look at the bottom of chassis and see the connection to and from
the Smps,for the Service Points.
If to technical,you might send the chassis out for repair if the Tube is Good.
Good Luck!
 
yeah, I don't do schematics, I was given a 27" chassis with blown HOT/flyback, I'm sure there's little odds and ends I can rob from that if need be.

if I replace the HOT with that other kind everyone on here raves about lately, and the flyback happens to be bad, will that take out the HOT too?

or can I punt on this one and just fix up the 27" chassis... weren't the Polos like universal yokes and can work on different size tubes? it's a 25" Polo I have.

re-reading what I just said sounds noob as fuck, but I don't care, nobody gives clear answers but you. heh
 
yeah, I don't do schematics, I was given a 27" chassis with blown HOT/flyback, I'm sure there's little odds and ends I can rob from that if need be.

if I replace the HOT with that other kind everyone on here raves about lately, and the flyback happens to be bad, will that take out the HOT too?

or can I punt on this one and just fix up the 27" chassis... weren't the Polos like universal yokes and can work on different size tubes? it's a 25" Polo I have.

re-reading what I just said sounds noob as fuck, but I don't care, nobody gives clear answers but you. heh

Thanks.

I'm sure i will make some mistakes,in somethings i say and need
to be rewitten, just pm me and i will edit it. When i write it wrong.

These chassis can need alot if your not going the replace a few parts
and restore the circuits,then forget it and get a Wells gardner Etc
med res. I don't see other model to be interchangeable.
Need to list your CRT #A and yoke # and readings.
I have a list of the ones i have seen, they have different readings for size'z.

I find the High Voltage regulation to be a problem.
Due to the Retrace and Safty Caps.
They open up under load the HV jumps up and Slams the HOT
enough of this and it can short winding in the fly.
Then agian We seen the fly spark out the side and the HOT still be good!
The fly could fail on its own, and short the HOT, If it bad.
I wouldn't replace it every time i did a cap kit!
Sometime's during TS it may eat some HOT to get fixed right
If i try replacing just few parts and not all the ones i should replace at once!
If HOT has been overheated it needs to be changed.
Or it could fail own its own. Bad connections can be another problem
Its the type and age of caps used in the HV circuit thats all.
Thats my take on what i believe is why they don't last after
just a cap kit and fly and HOT. And Upgrading the HOT is more because
the older is obsolete and uping the collector /emither current
won't fix the problem,in my opinion.
 
Last edited:
Back
Top Bottom