Hantarex 900 monitor focus issue

[Belike]

My Pac & Paint's monitor acts very strange, there is bad focus and some convergence problems on the title screen, but when the demo or a new game starts, there is a normal bright screen.(the right side of the monitor is a bit purple, but I guess it's a degaussing problem).
I tried to adjust the focus when the title screen appears, but it didn't help.
I left the machine switched on more than an hour long and all the focus gone, even when I play the game.
I turned it on again after a few hours and the focus came back, but just for the gameplay, the title screen is the same without focus.
Some pics:



And  a bad quality video:
http://www.youtube.com/watch?v=hMiu-424jow
Any input would be appreciated.  

[Robinholland]

Turn back your contrast and brightness or screen voltage on your flyback

[level42]

Turn back the brightness pot (I don't mean the SCREEN pot on the HVT but the real "brightness" pot.

[level42]

Haha, Robin and I posted at the same time. I don't think it's the "screen" pot though Robin because then the dark area's on the screen would light up too....

[Belike]

Ok, how is the flyback look like?
And if we talk about flybacks, do you know any existing sources where I can buy some for hantarex 900 and 9000?

[level42]

HVT=Flyback. Looks like this:



The mostly have only 2 pots though (this one has three)

Here's an explanation:

http://electronicrepairguide.com/flyback-transformers.html

But as I mentioned I think you shouldn't touch it. First the brightness back (and maybe the contrast)

[Etienne MacGyver]

The MTC 900 that is used in the zacc's dont have the 2 pots on the flyback itself..

the focus is on the "block" on the neckboard (folow the wire that comes from the "suction cup" on your monitor to the neckboard)

The brightness is also on the neckboard, and you can put your trimkey or screwdriver through the hole in the neckboard to ajust it:





its 21 and 22

ps i wish you luck without a desolder station if you want to replace them....  

[Belike]

Thanks for the input.
Any ideas where to buy replacement flybacks?
I have 3 other monitors with dead ones.
Maybe this will fit?

[level42]

Wasn't there a French shop selling them ?

[Vnera]

http://www.coin.demon.co.uk/-video.htm#otherm

is a site that i found. i'm trying to fix up 2 hantrax monitors my self. the type i'm  working on is MTC9110.

The site also has some information about fixing the monitors and a check for fixing basic problems.

[baritonomarchetto]

Not sure there's a MTC900 replacement flyback... be sure it fits your model because Hantarex MTC900, MTC900/E, MTC9000 are completely different models

[Etienne MacGyver]

http://www.donberg.ie/descript/h/hr_6051.htm

200 € 

[Belike]

http://www.donberg.ie/descript/h/hr_6051.htm

200 € 

Interesting price!

[Etienne MacGyver]

dont know if that is the correct flyback, there are more than 1 revisions of the chassis:

MTC900. This has two main boards, one about half the size of the other. The main feature is the Brightness, Contrast and Degaussing controls mounted on a black plastic bracket. This are on a long fly lead and is either mounted on the chassis or remotely in the cabinet. This plugs into the smaller board on the left. There is also the main power supply board mounted vertically on the chassis side to the left. The scan coil plug is on the far right hand side.

There are two versions of this chassis. To determine which type you have, you need to look at IC3 mounted on a heatsink just behind the six set up controls on the main board. If you have a TDA1470 (pins on both sides) mounted on a "U" shaped heatsink you have version 1 and if you have a TDA 2653A (pins staggered on one side only) mounted on a "L" shaped heatsink you have version 2. (This is also used on the MTC900E, look at other features too). The manual for version two only reflects this in the circuit diagram, and not in the pictures or on the cover.

source

[Belike]

dont know if that is the correct flyback, there are more than 1 revisions of the chassis:

MTC900. This has two main boards, one about half the size of the other. The main feature is the Brightness, Contrast and Degaussing controls mounted on a black plastic bracket. This are on a long fly lead and is either mounted on the chassis or remotely in the cabinet. This plugs into the smaller board on the left. There is also the main power supply board mounted vertically on the chassis side to the left. The scan coil plug is on the far right hand side.

There are two versions of this chassis. To determine which type you have, you need to look at IC3 mounted on a heatsink just behind the six set up controls on the main board. If you have a TDA1470 (pins on both sides) mounted on a "U" shaped heatsink you have version 1 and if you have a TDA 2653A (pins staggered on one side only) mounted on a "L" shaped heatsink you have version 2. (This is also used on the MTC900E, look at other features too). The manual for version two only reflects this in the circuit diagram, and not in the pictures or on the cover.

source

Thanks Etienne.
I took this week off from work to take care of my cabs, I will investigate which type of the chassis I have.
Prepare for a lot of noob, aracde related questions!