1084S-P LOPT+HOT replace

[roy_bates]

Hi, can you help me? i'm changing right now the flyback and the h.o.t. and i have a question, the flyback has 3 wire, the red one for "tube", the grey one on the "tube" pcb et the black one go inside a plastic module both side, how do you remove this one to put the new flyback?

i know this is an old thread.


you dont need to remove those leads from the flyback itself the new one should come with these installed.

but,since you asked how to remove the leads from them you just twist the cable and pull at the same time until it comes out.

its better to desolder the grey cable from the neck pcb and twist and pull the black one from the connector that goes on the neck,then desolder the whole lopt from the pcb and install the new one.

[e278c0ffbca5f4a6caaa599fa]

as i am a new member please i need help for my 1084 monitor ,i replase the flyback and the HOT transistor now my monitors red light operates but no picture i try to adjust the screen and focus but nothing happens,the only thing is that the noise stopped ,i check all the weldings eveything seems to be ok,any help will be appreciated.thanks Harry

[jcarvalho]

Did you replaced horizontal transistor of 1084s? When you change the flyback, you MUST change the horizontal transistor

as i am a new member please i need help for my 1084 monitor ,i replase the flyback and the HOT transistor now my monitors red light operates but no picture i try to adjust the screen and focus but nothing happens,the only thing is that the noise stopped ,i check all the weldings eveything seems to be ok,any help will be appreciated.thanks Harry

[roy_bates]

have you checked the fuse(although if thats gone it wont at all) and all the power transistors for the power supply?

and checked the 128 volt line?

and try to get hold of the service manual for test points.

[e278c0ffbca5f4a6caaa599fa]

the horizontal transitor is the HOT philips bu 508a ? this is what i changed,before i replace those 2,flyback and bu508a i had the high frequensy noise going down and no power lihgt.now i have the power light on and no more the noise, but i found that if i put my back of my palm in the screen i dont have this electrostatic effect in my hand.

[jcarvalho]

yes the bu 508a is the horizontal transistor. Does the screen gets brighter when you turn the monitor on? Did you fitted the wires from flyback correctly? that wire with a rubber thing is well fitted on top of the crt?

[e278c0ffbca5f4a6caaa599fa]

Yes i cheked again this morning i removed the red with the rubber cup and fitted again securelly the black goes inside the plastic cover in the neck of the tube and the thiner grey goes to left in the right side of cvbs-lca switch. is that correct ? still nothing and again no static with my back of my palm infront of the monitor. when i switch off i see a very weak flash in the center of my monitor.

i also notice that when i removed the rubber cap and try to dishcharge with a skrewdriver it seemed that no current was on it. i can also say that when i turn off the room light i can see that the back of the tube is lighting on.

[e278c0ffbca5f4a6caaa599fa]

this is my last try, wth a screw driver mains tester close to the rubber cup it doesnt light,so i dont have the high voltage at all,i change again a new HOT transistor nothing again i dont beleive that the new flyback is faulty it was sealed in a box i am desperate i think this is the end of the story......

[roy_bates]

did you check the 128 volt rail?

[e278c0ffbca5f4a6caaa599fa]

no i wiil do it now thanks.