Hantarex Polo 25" (I think)

[enter]

Hi guys, hoping someone might have an input on my prob.

Recently acquired a Killer Instinct cab, converted to tekken 3. It cost me little or nothing and was just delighted to get it. To cut a long story short Im having the following issues with the monitor (which I think is a Hantarex Polo 25" - verify from link below?) :

1) Pincushion - the horizontal pincushion pot is maxed out, yet the edges of the screen are heavily concaved inwards at the middle.

2) Whiteish/Blue horizontal lines visible when the screen fades to black. As soon as it gets bright they dissappear again.

3) The brightness pot on the sub board is having no effect at all.

Somebody from a different forum has hinted that the chassis/monitor combo may be incorrect (see thread & photos here http://www.boards.ie/vbulletin/showthread.php?t=2055498989 ). If this is the case, then Ill buy a replacement but Id really like to be 100% sure its not something different causing the issues. Could it be a cap kit? From reading different articles, there is mention of an east/west deflection board....if its applicable to my monitor then I cant see it so maybe its missing. Anyway I'd appreciate any input guys.

[grantspain]

i would check for bad solder joints first

[enter]

Cheers Grantspain, Ill do that. Is there anywhere in particular on the chassis I should focus on? Sorry to sound so noobish, I guess I am when it comes to arcade monitors. Ive built jamma rigs etc so Im handy enough with a soldering iron, just a little lost when it comes to monitors. Anyway Ill report back my findings, thanks agan.

[grantspain]

that is indeed a polo 1 chassis
there could be many possibilities to your fault,
check for dry joints on the chassis around the flyback,on all connectors and neck card crt socket

check the pots on your remote board are good and the cables read continuity from chassis plug to remote plug

the pincushion could be down to leaky east/west diodes  D134 AND D135
does your horizontal size pot work??

[enter]

Cheers grantspain, Ive checked for dry joints today on the chassis/flyback/neck board. All looks well, so I just reflowed some of the connections.

Ive checked the remote boards cable continuity, and traces to pins; again all here seems well.

I located D134/D135 on the chassis, didnt appear to show any leakage signs, I just reflowed again here.

With regards to the pots, horizontal does work with a very limited field of adjusment; from min to max the only adjystment that will show is about 2 inches of the screen and this is near the very end of the pots rtange, shows no effect until it gets to this point. Vertical works fine, as do the horizontal/vertical syncs. Brightness has no effect whatsoever, contrast works fine.

Any other suggestions, Ive ordered a cap kit anyway so see how that goes. The guy on the other forum seems to think that chassis is for a 14" screen, any way to eliminate this theory?

Cheers

[grantspain]

a leaky capacitor is not something you can physically see

if your cap kit don't fix(which i don't think it will) then change
T117 BC5588
T118 BDX53C
D134 BY228
D135 BYV95C
and check the bride coil L107

[qrz]

a leaky capacitor is not something you can physically see

current leakage that is   

seepage of the electrolytic fluid is somewhat easy to see ( SMELL !! )

as for ur brightness issue , also have a look at the bright limiter circuitry .
may have a resistor that has changed value

qrz

[grantspain]

a leaky capacitor is not something you can physically see

current leakage that is   

seepage of the electrolytic fluid is somewhat easy to see ( SMELL !! )

as for ur brightness issue , also have a look at the bright limiter circuitry .
may have a resistor that has changed value

qrz

yes  i meant to say diode

[qrz]

 !no problema!

and diodes can be faulty even when they "test" good.

been fooled before 


qrz

[enter]

Cheers guys, Ill update as soon as I have everything checked. And if I spot any leaky capacitors Ill be sure to post about them   

[enter]

Kit arrived, so just about to start it now. Ive made sure the cap kit is complete, and Ive identified all locations on the board bar one - c401. I cant find any cap locations that go even nearly that high. I can only see up to late C180's. Ive checked the neck board, and the remote board and no joy - can anybody advise? Cheers

[grantspain]

its on the remote control pcb

[enter]

Cheers Grantspain, your right it is on the control board - but mine is listed as c40. (including the .) so maybe a misprint. on the pcb? Anyway Ive completed the cap kit and its made no diff whatsoever, nevertheless I'd have done it as a point of preventative maintanence anyway because Im not sure if it had ever been done before. So looks like next stop is east/west deflection diodes:

https://www.chsinteractive.co.uk/electrical-components/general-components/semiconductors/diodes/diodes-standard-type/by228-dio.htm

https://www.chsinteractive.co.uk/electrical-components/general-components/semiconductors/diodes/diodes-standard-type/byv95c-by208-by210.htm

https://www.chsinteractive.co.uk/electrical-components/general-components/semiconductors/transistors/bd701-bdx53c-bd901.htm

Can you verify these are correct? Or suggest a better retailer, as this one doesnt recognise BC5588. And one that will post to Ireland? Cheers guys thanks very much so far

Edit: With regard to checking the bridge coils, should I be checking for continuity on all four points of the coil?

Ive also attatched photos of the fault

[grantspain]

you are in Ireland are you?anywhere near Tullamore
it a bc558b not bc5588
change T117 bc558b and T118 bdx53c-you can get both from www.dalbani.co.uk
they also do the by228 and byv95c east/west diodes

[enter]

Im in Dublin, but its not too far from Tullamore I presume you have family there? Thanks for the link - very much appreciated I owe ya one! Ill go ahead and just replace them, so results will be updated in a few days when they arrive. Thanks again

[enter]

Ok guys the stuff arrived today. Ive replaced the east/west diodes and the two transistors. No real inprovement 
There is much better range on the pot for adjusting horizontal size, it goes from very small to almost full size now, whereas before there was very very little movement. The brightness pot also seems to work now. Im still left with heavily hour-glassed sides though as per the pictures.

I suppose the next step is the bridge coil L107. There are 5 contact points on the coil, the three in a row all have continuity between them. The other two at the bottom dont. How do I go about checking this coil correctly? I havnt tried adjusting it yet, I need a big mirror which I will do on Saturday.

Also before I put more money into this there is one point nobody has made a comment on, it has been suggested that based on the pictures, the chassis being used is for a 14" monitor therefore its range is maxed causing this effect? Can this please be eliminated?? Thanks as per usual. Ive uploaded photos of the chassis in place.

[grantspain]

if you have swapped chassis from a smaller monitor that could cause the problem also alot of polo needed an extra east/west correction board to match to different crt

[enter]

Hi Grantspain - Ive no ideal of the history of this cab, it was like this from the moment I got it. Are there any part numbers on the chassis I can confirm its correct with? Also where would the extra control board go? Ive no free sockets left on the chassis?

[grantspain]

there is a number on the flyback transformer,if you get that i will tell you what size crt it runs

[enter]

Ok Grant, I have the chassis here beside me and the details of the f/b are as follows:

Diemen HR Spain
Diemen 9952003915
HR 1ACP 7191
28028800

I have included some photos of it too, and some of the neck board just incase. I definitely think this flyback has been changed or worked on before, as youll notoce some of the bad soldering on the underside of the pcb. Also there is a resistor R234 which is now on the underside of the pcb, and topside of the pcb where it should be is a little scorch mark. Any idea what this resistor is for? Perhaps it failed at some stage and because of the awkwardness of where it is on the pcb, a lazy tech just soldered it on the solder side. Anyway looking foreward to hearing you input.

Ps I can get a polo mk 1 chassis here http://www.videotronicsuk.com/ for 100 Sterling delivered to Dublin, just incase this one is a lost cause...

[grantspain]

not sure what is going here but i reckon that is the wrong flyback transformer,the resistor is the wrong value for a 25" chassis as it should be 10 ohm not 20 ohm

now i am trying to work out whether thats a 25" flyback on a 14" chassis or an adaption on the 200v to run the crt

i will contact hantarex on monday to find out what they think

[enter]

Thank you very much Grant - really appreciate that 

[grantspain]

i have not forgotten you,Chris the tech ay Hantarex is now semi retired so I have to email him via Hantarex for info
One thing he asked is if there are any numbers on the main chassis-atm he is thinking what I am thinking,that you have an adapted 14" chassis running a 25" crt

[enter]

Hi Grant, cheers for the help I realise its a bit above & beyond - I owe ya.

Ok numbers on the chassis pcb, let start with the solder side of things:
TF 05 50148373
1A94V0

On the parts side there isnt much to go on really:
T3.15A
250V
TF05

Hopefully these may shed some light on this and put it to bed. Thank again Grant

Paul

[grantspain]

hope to have a reply tomorrow from hantarex but i got a feeling i am correct about this,i have worked on hundreds of polo chassis and all the 25" + normally have a east/west correction board on them
we find out soon enough

[enter]

Hi Grant, did you ever hear anything back from Chris about this?

Cheers

[grantspain]

he never replied,i will phone them tomorrow

[enter]

Appreciate it. Ill wait till you have time too if your busy theres no rush. Cheers

[grantspain]

chris was on holiday,i should have an answer in the next few days i hope