Author Topic: The most stupid Hantarex Polo 25" problem ever (Read 8336 times)

Owl · « **on:** August 30, 2010, 08:14:59 am »

Greetings guys,

I have an Hantarex Polo 25" monitor that i had to replace the flyback and all electrolitic caps. After that the monitor didn´t powered up and was making the tic-tic sound... Had the correct voltage at TP6 (+138V) and still nothing. Anyway i found the problem and corrected it but a new problem showed up:
the monitor displays the image but.. a veeeeeeeery WIDE one and had no H. Amp. control. Once again found the problem and finnaly the monitor work perfectly... well... quite perfectly as the damn monitor ONLY WORKS FINE OUTSIDE!! the cabinet.

OUTSIDE the cabinet the monitor gives a perfect image. Once installed in the cabinet, it gets light green at the lower corners and light blue on the top ones.

Anyone has an idea why the hell is this happening? I worked with monitors before and never saw anything so stupid as this. :S

Franco B · « **Reply #1 on:** August 30, 2010, 08:25:04 am »

Are there any unshielded speakers or anything else magnetic that may be causing the problem?

Owl · « **Reply #2 on:** August 30, 2010, 08:32:26 am »

nop.. nothing at all. :S

i can see the monitor getting green as it gets inside the cabinet. Its a Rene Pierre cabinet. The monitor was always there and never had this stupid problem before

Rick · « **Reply #3 on:** August 30, 2010, 08:48:29 am »

Quote from: Owl on August 30, 2010, 08:32:26 am

nop.. nothing at all. :S

That can't be entirely true. *Something* has to be interfering with the normal operation of the monitor, since, as you say, "i can see the monitor getting green as it gets inside the cabinet." That tells me that something inside the cabinet, or possibly even the cabinet itself, is causing some type of magnetic/electrical interference with the normal operation of the monitor. Can you post pics of the cabinet interior, where the monitor goes in? And possibly a pic of all the internals?

Owl · « **Reply #4 on:** August 30, 2010, 09:14:24 am »

The cabinet is simply wood made.

i will post a few pictures for you guys to have an idea...

Rick · « **Reply #5 on:** August 30, 2010, 09:16:41 am »

I'm wondering, since you mention it's occurring at the corners, if there might be some steel angle-brackets holding the wood surrounding the monitor? If so, it's a possibility they're holding some residual magnetism... Of course, I'm talking through my hat, here. I'll await the pics.

Owl · « **Reply #6 on:** August 30, 2010, 10:04:59 am »

Here´s a few pictures of this "piece-of-work"

Rick · « **Reply #7 on:** August 30, 2010, 10:11:25 am »

Can you take a picture *into* the case, with the monitor leaning outward like it is? (So, take one of the last pictures, and point your camera down and in, from above.)

Owl · « **Reply #8 on:** August 30, 2010, 10:58:23 am »

HaRuMaN · « **Reply #9 on:** August 30, 2010, 11:02:36 am »

Dumb question, but have you tried de-gaussing the monitor after installing it back in the cab?

Rick · « **Reply #10 on:** August 30, 2010, 11:04:51 am »

Ok. I have a request that you might find really strange. (After degaussing, of course, and seeing if that works.) Can you move the cab to another spot in your room? I'm wondering if maybe there's an electrical wire somewhere in your wall that might be running vertically through some of your studs, and possibly might be causing the problem. I know I used to have an old CRT that had some problems like this, and they disappeared when I moved my desk.

Owl · « **Reply #11 on:** August 30, 2010, 12:31:27 pm »

The POLO´s auto degauss at startup (at least the european model)

I already tried to move the cabinet to somewhere else... the problem remains

grantspain · « **Reply #12 on:** August 30, 2010, 03:41:45 pm »

perhaps the PTC component is faulty

qrz · « **Reply #13 on:** August 30, 2010, 04:16:40 pm »

MANUALLY degauss inside the cabinet .
run coil over EVERY piece of steel/nut/bolt/screw near the crt.

something has a stray magnetic field .

i have seen this symptom in tv servicing. had a couple that metal framing was magnetized
by an all too near lightning strike.
in each instance , it took a few tries to neutralize the field.

be persistent !

Owl · « **Reply #14 on:** August 31, 2010, 07:21:49 am »

If the PTC is bad, is it suposed to have a clean image if the monitor is outside the cabinet? :s

and... how can i degauss it manually?

grantspain · « **Reply #15 on:** August 31, 2010, 05:19:18 pm »

Quote from: Owl on August 31, 2010, 07:21:49 am

If the PTC is bad, is it suposed to have a clean image if the monitor is outside the cabinet? :s

and... how can i degauss it manually?

yeah don't always work like that i am afraid
if your degauss circuit is working and you still have a gaussed screen then the only explanation is a very powerful magnetic field close by

manual degauss by way of a manual degauss wand(you see them on ebay)

Mikezilla · « **Reply #16 on:** September 01, 2010, 01:11:27 pm »

I just used a really powerful speaker magnet that I had lying around to just pull the colors away. It was a pain, took about 10 mins but I got it. It was free too!

Owl · « **Reply #17 on:** September 02, 2010, 06:30:27 am »

Well... i´m up to anything at the moment, so i will start with the speaker...

i really have no idea of whats causing the problem... :S

qrz · « **Reply #18 on:** September 05, 2010, 09:01:34 pm »

to deguass , an alternating magnetic field is required .

a degaussing coil produces an alternating electromagnetic field at 50/60 hz (pending country)

i 'spose using a speaker one might be able to induce enough of an opposing field to nuetralize.
though i'd think a bit difficult to accomplish with a fixed field...

Owl · « **Reply #19 on:** September 16, 2010, 08:39:43 am »

i used a pretty strong magnet and it indeed fixed the colors but it doesn´t give a neat look to the arcade since the speaker magnet is outside the cabinet, so i will have to find out another way to fix it. I already tried to push the colors with the magnet to the proper places but they return to the wrong places after a while if the magnet is not present :s

another thing is... i don´t have 138v at TP6 nomore. its alot higher than that in fact (around 180v), but the monitor works fine :s

qrz · « **Reply #20 on:** September 18, 2010, 08:31:16 pm »

check the regulator circuit* . am surprised the HV shutdown is inactive . that should be checked as well .

*assuming you're using the correct ground point

Owl · « **Reply #21 on:** September 20, 2010, 07:40:57 am »

as i stated before... i´m up to anything atm...

what ground point are you refering to?


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