My Hantarex Polo 25 is Sparking!!! (flyback transformer)

[krick]

Today I fired up my cabinet and I heard electrical arc zapping noises and I quickly pulled the plug.

Here's some pics of my monitor...

http://mame.3feetunder.com/hantarex-polo-25/

The large component in pictures 5 and 6 is sparking out the top.

Questions...

What is that part?
Why would it be shooting sparks out the top?
Is it something that can easily be fixed/replaced or is it a sign that the whole monitor is on it's way out?

[qrz]

that would be the horizontal output transformer/ IHVT / flyback..
this device produces the 2nd anode voltage for the crt .
this voltage will vary somewhat for screen size. but , is usually 20kv-30kv.
it takes approx 10kv to arc 1 inch . the distance also varies with humidity.

if your de/soldering skills are good , it can be replaced .
the crt should be discharged prior to removing the anode lead , and again prior to connecting the new
one .  no surprises that way 

qrz

[Kevin Mullins]

You will most likely find a crack.

[krick]

if your de/soldering skills are good , it can be replaced .

Bob Roberts has a flyback + capkit for $23.

My soldering skills are decent.  My desoldering skills... not so much.   However, I have successfully re-capped a few ABIT slot-1 motherboards, so I guess my skills aren't that bad.

I'm wondering if my local TV repair shop would do the job.  I'm sure they have much better soldering equipment than I have.

I don't know if they'd have any way to test an arcade monitor though.

[Kevin Mullins]

I don't know if they'd have any way to test an arcade monitor though.

If the monitor is "working" .... just arcing...... then all they should have to do is pop the new flyback in and send you on your way to put the chassis back in.

[krick]

I don't know if they'd have any way to test an arcade monitor though.

If the monitor is "working" .... just arcing...... then all they should have to do is pop the new flyback in and send you on your way to put the chassis back in.

True, but I'm thinking that a cap kit wouldn't hurt too while I have it apart.

After installing a cap kit, how much "adjusting" needs to happen to get it working again?  My monitor has a ton of adjustment pots and I really don't know what most of them do outside the vertical/horizontal size and alignment ones.

[qrz]

don't bump any of the pots and adjustments should be minimal 

qrz

[krick]

I've managed to get the main board out of my chassis.  I had to unplug the neckboard from the tube and remove that too since there were four wires that are soldered that connect the two boards.

I'm looking at the current flyback and I notice that the black wire that connects to the neck board seems to be permanently attached to the tube socket.   Can I just cut the existing wire and splice in the new wire?  If so, I assume I need to solder the connection and cover it with heat-shrink tubing.  The reason I'm concerned is that the flyback wires are high voltage.  If they were normal 5v wires, I'd think nothing of cutting and splicing them.  I think there's a red wire that may need to be spliced as well.

Any advice?

I can post pictures if needed.

[Kevin Mullins]

Post a pic if you can....

The black wire sounds like the DAG ground wire that goes to a braided strap of sorts that wraps the back of the tube. Can cut and splice that with no problems. I usually add male/female connectors for future removals.

Now the RED wire I'm not sure what you're describing....if it goes directly to the flyback then it absolutely needs unsoldered and resoldered properly.

[krick]

I've circled the red and black wires where they leave the flyback...




Here's where they attach to the neckboard.  The red one is easy to unsolder and attach the new one.  The one that I'm unsure of is the black one.  Notice that it goes directly into the white tube socket.  There doesn't appear to be a solder connection on the other side, so I guess I'll have to cut and splice it.  There's 4 other small wires (brown, black, orange, yellow) that connect the neck board to the main board anyway, so if I wanted to add a male/female connector inline, I'd have to add one for them as well....

[Kevin Mullins]

Ah.... that's the FOCUS line.... high voltage.

Typically there is a little piece on the white neck socket that you can either open to release that line or there is a piece that comes off like a cover to unsolder that line.
I can't see either of those options from that angle of pic.

There are others on here more familiar with the Hantarex models, maybe they'll pop on and be able to instruct further.

The red one.... yes, just unsolder it from the neckboard and resolder the new one in.

The other four wires you mentioned shouldn't need to come off at all.
Just leave that all attached as is.

[qrz]

looks like a murata socket  ( ? ) and thus a solderless focus connection.

should be a "clip" that holds the cover in place . once located , a gentle push of a screwdriver will relase it allowing the focus lead to be removed .

after inserting the wire, push the cover into place to seal

qrz

[krick]

looks like a murata socket  ( ? ) and thus a solderless focus connection.

should be a "clip" that holds the cover in place . once located , a gentle push of a screwdriver will relase it allowing the focus lead to be removed .

after inserting the wire, push the cover into place to seal

Anyone want to take bets on the plastic being brittle and a "gentle push of a screwdriver" turning into a disaster?
I'll keep you posted.


I'm still flip-flopping on whether I should do the the cap kit or not while I've got it apart.  I didn't really have any complaints about the picture.  I'm sure that the colors could be brighter and the focus could be better, but that may just be adjustment issues and not cap related.

I did notice that when feeding a signal from an ArcadeVGA through a J-PAC that the vertical hold was VERY sensitive with some resolutions and sometimes I couldn't get the picture to stop rolling until the monitor warmed up.  I also notice that when running 800x600 interlaced, there was a little distortion at the top of the screen.   Again, I don't know if either of these issues have anything to do with aging capacitors or not.

The monitor is dated 1992, so it's 17 years old.  When do monitors start really needing re-capping?

As a side note, while looking over the caps in the kit and comparing them to the ones on the board, it appears that the kit is missing the two largest capacitors, the ones in the power supply area, C106 and C108.  They are both marked "200v 470µF(M)".  Any thoughts why they were omitted from the cap kit?

[krick]

I don't think I can get the cover off this socket without breaking it.  The cover has two square holes and the bottom piece has tabs that pop through and lock into them when you push the cover on.  I tried pushing in on those tabs and prying on the cover, but I'm pretty sure it will break if I put anymore pressure on it.  Any advice?  Here's a pic...



EDIT: Upon closer inspection, I'm not so sure that this cover actually comes off.  I think that the socket is made in two pieces that are snapped together before it is soldered in.  I really don't want to have to de-solder the socket, but it looks like that's going to have to happen.  Ugh...

[grantspain]

the polo have a few different crt sockets,that one looks like the type that actually hinges from from the centre,otherwise there will be a clip on the side

[Oni2382]

Buy a de soldering braid. An absolute must for de soldering. I got one from Happ and have NOT regretted it one bit.

[qrz]

push down and hold, the wire may then release .

for the last  30yrs  the focus lead is readily accessible.

just a matter of how the skt is constructed .  no need to make it difficult ....


qrz

[krick]

push down and hold, the wire may then release .

for the last  30yrs  the focus lead is readily accessible.

just a matter of how the skt is constructed .  no need to make it difficult ....

Trust me, I'm not making it difficult.  The socket doesn't operate in the way anyone here has described.  I tried pushing, pulling, prying, etc...  I don't see any way to get it apart without breaking it.  SOMEONE has to have replaced a flyback on a Polo 25 and run into this type of socket besides me.

[qrz]

ok, lets get some various views of this socket......preferably closeups

there should be a way of releasing the wire.... besides using few pounds of C4.   

just a matter of finding it...




qrz

[krick]

I emailed Bob Roberts about my situation and he said...

There are usually either tabs that you can push to release the cap which
opens hinge-like or some have just a slot for the blade of a small
screwdriver to be inserted to release the dog on the wire so that it can be
pulled out. On that type as you push the new wire in the internal dog grabs
it & holds it. On the hinged cap type it will be soldered to a terminal inside.

With the knowledge that the wire probably wasn't soldered inside (no obvious hinged design) and no obvious place to insert a screwdriver to "release the dog", I decided to try twisting the wire while gently pulling on it and it just popped out.  So I got my desoldering braid out, removed the old flyback, and soldered the new one in.  I pushed the new focus wire into the old hole and it seems to have grabbed ahold of it pretty tightly.

I just finished hooking it all back up and my monitor works perfectly.  I think it looks really good, so I'm going to skip doing the cap kit for now.

Thanks everyone for your help.

[Level42]

Ancient thread I know......but it just saved me from going  nuts over that weird CRT connector.

Had to replace Polo flyback for the first time and was completely puzzled how to open the CRT connector.....which as explained above was actually not needed. Followed Krick's instructions in his last post and it seems to be good to go....just will know 100% when the chassis goes back into the machine.....a Deluxe Oit Run :

[wrkey]

Replaced the flyback on a Polo 25 and ran into the focus wire problem.  I followed the advice here and twisted/pulled on the focus wire at the neck connection and it broke off... inside the connector.   Now I have just enough wire left inside the connector so I can't insert the new wire nor access to the old broken piece to pull it out.

This sucks.   Any new ideas or instructions on this?   If now, anyone got a neck board for Polo 25?  Sigh....

[grantspain]

just replace the crt socket-easy