The NEW Build Your Own Arcade Controls

Main => Monitor/Video Forum => Topic started by: perjmolsen on January 26, 2020, 04:50:50 pm

Title: Hantarex polo 25-28 No brightness control (SOLVED)
Post by: perjmolsen on January 26, 2020, 04:50:50 pm: Hi :cheers:

Again a Hantarex Polo trying-to-fix

My Hantarex Polo has no Brightness control, nothing happens at all when I turn the brightness pot.
Also when the picture changes between black and white, the picture gets nearly all white, and then normal "black" again.

R240 a 180K resistor where OL, changed it to a new 180K but still no brightness control, I checked the resistor afterwards and it is still OK.
D401 is OK

What am I missing? :notworthy:
Title: Re: Hantarex polo 25-28 No brightness control
Post by: princess prin prin on January 27, 2020, 05:55:39 am: Check the other parts in the beam current limiting circuit starting from pin 7 of the flyback: R232, C176, D150, C180 and R233, R239, R240.
Title: Re: Hantarex polo 25-28 No brightness control
Post by: perjmolsen on January 27, 2020, 05:55:56 pm: HI :notworthy:

I have checked them all out of circuit including R238, all tested as in spec :dizzy:

The only components that where a bit off where the two caps
C176 100nf 250v replaced with a new 104J 250V poly cap
C180 10n 630v replaced wit a new 103J 400V poly cap

Still no change in brightness when I turn the pot on the remote board.

I have made a small video of the brightness issue when the picture changes

https://www.youtube.com/watch?v=dAiTmbxs3vY
Title: Re: Hantarex polo 25-28 No brightness control
Post by: perjmolsen on January 27, 2020, 06:35:17 pm: Well.... :o

Now it is fixed........ :banghead: :banghead:

The only thing that I not did test where the pot it self.... sure that where the issue....!

So funny how things work if a new one is put in.... :laugh2:

https://www.youtube.com/watch?v=LqsmpHRPAxE

Now time to :cheers:
Title: Re: Hantarex polo 25-28 No brightness control (SOLVED)
Post by: MKFan4Life on March 22, 2020, 03:12:17 am: Congrats on the fix. As I was reading I was like, is he going to check the pot itself? Lol! Glad you fixed it up!