2 Hantarex Polos: blanking and high brightness issues

[mecha187]

I realize I've been a member here for a little while, and also realize this is my first thread, and it's of the TL;DR variety, but I feel that I need to document everything I've done to improve the chances of figuring out what to do to fix these by avoiding suggestions of things I already did.

I was working on a pair of Hantarex Polos last week and got both of them to work. testing them with my supergun and plugged into a wall outlet, they looked tremendous. ran them for about an hour each with no issues. once I went to install them into my Killer Instinct 2 however, that's when the proverbial ---steaming pile of meadow muffin--- hit the fan.

I will call them Polo #1 and Polo #2.

Polo #1 had a symptom last week of having HV, but no heater glow. thinking I had a bad NEW flyback, I installed an old one that I knew still worked. after multiple inspections of the neckboard, I moved onto the flyback, where I discovered a huge crack that spanned about 8 traces. I patched all of those with solder and voila, I had heater glow again, and the monitor looked perfect. I accidentally touched the color drive heatsinks together though and popped R40. I had another scrap Polo chassis that I sourced an R40 from and then it worked again.

so I got someone to help me pull the temp U5000 I had in KI2 out and put this one in and while it worked, the picture kept bouncing up and down. I cut it off and saved it for the next day when I opened the back door to find the anode sitting on top of the deflection board. I'm guessing the bouncing picture was from a poor anode connection, not sure how, but I know that from putting it back on and going to take it back off again it required zero effort to remove. so I took it out and went to install the NEW flyback in it again. I went to put it back in the game and was greeted to a white screen again, yes, I ---fouled up beyond all recognition--- up and touched the color heatsinks together when I was grabbing the neckboard to put it back in. so I found another 10 ohm resistor to throw in, but I decided I was sick of this nasty film being on the neckboard and opted to remove it and clean it with Simple Green. (STUPID with a Polo, I know)

this is where things get interesting. when I cleaned it and dried it, I put it all back together. I went to test the chassis again the next day and had no HV again, and just a buzzing from the neckboard. after further inspection a day later, yes, I soldered the ribbon cable on backwards. I put it back on correctly and now the monitor works with a white screen that changes from blue, to green, to red and back to blue again, etc. I checked my blanking resistors again and they were still good. I replaced IC1 with another with no change. I neglected to test T1, forgot about that one.

I also get a ticking sound the first 5 seconds the monitor's on that goes away.

what, pray tell, went wrong?

Polo #2 just had no power at all. very easy fix with this one though, R103 had a leg desoldered and the little transformer box next to it had a leg or two with crap solder joints. I ran this one and it looked just as good as Polo #1 with no major adjustments. however, naturally, once I dropped this in KI2 since the first Polo didn't make it, it formulated some new problems too. you can turn the Screen and Brightness all the way down and still see a bright picture. my school of thought is you turn the Brightness just low enough to make the pixels disappear, and you turn your Contrast just high enough (and a little lower) before the picture starts to bleed... however if you do that here, you get a green vertical line and periodically, not sure what causes it, because pounding on the cab didn't cause it (in case it was a cold solder thing), but the entire screen will be scattered with little blue dots. the Brightness thing could potentially be caused by the color pots being turned up too high, I'm not sure as I haven't messed with this one yet, but the blue dot thing concerns me, cause that never happened before. I didn't remove this chassis at all after I initially fixed and tested it, I left it on the tube, and I've never seen the blue dot thing before. I was always under the impression that if you turned the Screen all the way down that you should have a pitch black picture, or does that only apply to Wells-Gardner products? also, I don't remember exactly cause that was a few days ago now but... I think I wound up killing that R40 on this too cause I recall another white screen situation.

what's weird is I never encountered blanking circuit problems before, and I've certainly taken off a lot of Polo neckboards over the last few years, but after reading Fromm's flowchart for the Polos, now I've done it like 3 times.

[mecha187]

Thursday's my lucky day apparently.

the Polo #2 had a whining flyback, the sound would go away if you tinkered with the Screen control. the part that was bad however was if you tapped the monitor frame, the whole picture would flip out. I was ready to throw another flyback at it thinking the one on it was bad when I discovered that pesky pin that KLOV users insist shouldn't be soldered in and just leave it tucked underneath was in fact touching another pin. I moved it away and reinstalled.

then guess what happened? it flashed the same white screen with the rotating colors as Polo #1. so I threw a hail mary and pulled the flyback again and just soldered the pin that everyone on KLOV claims shouldn't be soldered and...

I got a black screen. ran the Test pattern, I saw vertical lines. I couldn't wait to try it on the other chassis and guess what...

I fixed that too.

so that pin that you're supposed to just ignore and leave tucked underneath the flyback? solder that bizarch, cause apparently you need it.

reason Polo #1 suddenly developed this problem was because I had an ORIGINAL flyback on it before (in the Tekken Tag screen). so... that is all.

---fudgesicle--- it. thanks everyone that read, it was a little out of left field but I figured it out.

happy gaming, my Killer Instinct 2 is happy.