Hantarex 25" Polo monitor woes :(

Hey guys I wonder if anyone can help.

I have just bought and collected a Europlay cab with a 25" screen. I tested it on site and it worked fine, good display and no probs. It had CPS2 SF Alpha in it and it was switched on and off a few times and ran for half an hour no probs.

After transporting it home I get nothing from the monitor. The games, different boards including my Neo ones, can be heard playing and the power supply is giving off the correct voltage. Nothing however can be heard from the monitor. No hum from the transformer or power up of the monitor. I have measured the voltage going into the chassis and it is there. No wires appear to be loose anywhere, yet I get nothing. It is a Polo 25" chassis and monitor. I have checked all connections to and from the chassis and they all seem good. Any ideas?

As far as chassis goes what are the bits to avoid? Just the larger capacitors, as I think I may have to remove the chassis and check about on it. And can a working chassis be pulled from one of my other machines and used? Or must I have the correct Hantarex chassis?

I would be grateful of any help guys.

I'm assuming you checked all of the obvious connections right? (power, fuse, etc...) Did you happen to have your adjustment board disconnected from the monitor chassis when you powered it on? If so, then look to your horizontal output transistor (HOT) as it’s probably dead. If the HOT is bad, the monitor will appear to not power on and you will see nothing on your screen. Here is a pic of my Polo 33 monitor chassis with the HOT circled in yellow.



Even though the HOT shown is a NTE2300, you can use a BU508A as a replacement. To be sure that the HOT is bad, perform a gain/diode test on the HOT. You may be able to use a monitor chassis from a smaller/larger sized Hantarex Polo monitor to replace yours if it gets to that point. Just be careful when working around the anode if you have not discharged the monitor or you will get a nasty shock. Good luck to you.

Thanks for the reply.

Yeah I checked the obvious, no loose connections I can see anywhere. Which I thought would be the problem. It worked on site, loaded up, a quick half hour drive and then dead.

I checked the fuse for continuity and its good and various power cables for voltage. The adjustment board has remained attached throughout.

The only cables not attached seem to be earth cables that don't appear to have a home. I might extract the chassis tomorrow and look for possible problems. Unless there is anything else you/anyone can think of.

Well I removed the old chassis and looked for any possible probs then gave in! Traded it in for a refurbed chassis at my local Arcade store. It is now working fine apart from concaving inwards at the sides on certain screens. Probably just needs adjusting somewhat.

Thanks for the help Meanbean, it may have been the prob you suggested, but its out of my scope!

It is now ready to be aesthetically restored and will be home to the new SF3 game providing I don't kill it, which I probably will.

See other thread if you have any experience with USA SF3 NG

Hrmmm...

Sometimes things just come loose when you move a system.

On situations like these... if the HOT is not shorted and the fuse is not blown, you should take the monitor chassis board out and check for cracked solder joints and repair them. Also look at the bottom of the board while shining a flashlight at it from the opposite side. It helps you to see if the board has any cracks that have broken the traces.

Cap kits are also easy to install, but in this case I'd go for the broken/cracked solder joints.

RJ

Yeah I did that but found nothing, no traces seemed to be broken. At least it is working now. I killed my CPS3 though!

On another note my only gripe with the monitor is H Amp. The screen leaves the side of the monitor, I have adjusted the remote pot board but it won't come in enough. The Pot only has the slightest movement on the screen and doesn't use the whole travel of the pot. Is there another pot on the actual chassis, I didn't notice one when it was off, but I wasn't looking!

Sounds like you need to adjust the width coil?. Just out of interest what is the name of the arcade store you got the new chassis from?.

Hi Ace,

It was from the arcade warehouse in Ponterfact. I need to adjust the width coil then. I like the auto discharging malarky. Can anyone tell me where it is?

If I had to guess, I'd say it's that coil right smack dab in the middle of the pic that meanbean posted above...

RJ

I have been reading up a little on them and I think you are right, that'll be it.

But I have also read it makes little difference from one extreme to the other. It seems like the adjuster is knackered on mine. Call it a clock!! From say 12 o'clock (Largest picture extreme) to 11 o'clock it shrinks about 10mm inwards. The pot then can move back to say 1 o'clock with no more effect. I wonder if changing the pot for a similar rated one will make a difference?

meanbean said:

Even though the HOT shown is a NTE2300, you can use a BU508A as a replacement.

Click to expand...

The BU508A does not have a built in efficiecy /damper diode, for horizontal output applications a BU508D would be more suitable.

On that chassis it looks as if the diode is discrete so a BU508A would work.

Well I adjusted the width coil today from one end to the other. The slug was fully out and I adjusted it fully in. I may have gained a cm but that is about it. There is so little movement on the remote pot I wondered if replacing that might do the trick? What do you think?

If you look at ttooddddyy's neo on the right, with MS on. On my display a bit of the M and the L of Metal are missing off the screen. And you can actually lose your character of the side! Credits displayed on games can not be seen also.

Do you think it is just the pot that might need replacing or do you think I need to change the capacitor that is near the width coil? I am not sure which it is though anyone with the same chassis got a photo of the cap that needs reducing?

Or any other suggestions? Like what to adjust to solve the concaved sides? Not noticeable when playing but like on MS again the scoreboard is bent inwards both sides, in the middle.

Cheers

Seeing as people have polo 33" here (even though there are some slightly different components from the chassi pcb I'm working on.) I wonder if anyone got the manual and can tell me the values of C170 & C174 on the 33" polo, my capacitors looks like a cross between charcoal and molten plastic.