Maker Pro
Maker Pro

hitachi 46ux13k chassis ap33 no picture

M

Mike

Jan 1, 1970
0
I got this chassis AP33 the original problem was, it had a good picture but
when you fi rst turned it on, the picture rolled, had horizontal tearing,
and jittering, along with the PIP not functioning at all. after it warmed
up, the picture would tear and jitter a little bit. almost like watching an
old VHS.


So, I read that the PIP board and 3-line board have bad caps.

First, I recapped the PIP board, and my pip came back. perfect pip, but now
my tuner died. snow.

anyway, it still had the tearing and jittering, So i removed the 3-line
module.

I seen one cap in that module where it was so bad, it eaten away part of the
board and traces. So I carefully removed that capacitor, and traced down
that board, wired a new capacitor in. replaced all other capacitors the same
way I did the PIP board.

Now, I stuck the 3-line back in, whoops, I got sound, I got OSD, i got no
pic. :-(

I checked and doublechecked that board over and over. I dunno what went
wrong. no picture.

am I foced to replace that 3-line? where do I get one?
 
M

Mike

Jan 1, 1970
0
one of them stupid STK4274s is out in it too I noticed. there is no green
correction and that part of the heatsink stays relatively cool.

So, I replaced it, and still doesnt have any green correction, but this time
the green STK gets too hot to touch in the matter of seconds, with or
without the conv yoke connected. rather odd, unless i got a dud STK.

any ideas? S-video works, so thats a good sign my comb is shot.
 
M

Mike

Jan 1, 1970
0
I found 2 2.2ohm resistors that connect the ouput of the STK to the yoke,
its open. Im going to have to order some replacements.
 
M

Mike

Jan 1, 1970
0
i dont think any fuses are open, as red and blue convergence is ok.
 
D

David Naylor

Jan 1, 1970
0
Mike said:
one of them stupid STK4274s is out in it too I noticed. there is no green
correction and that part of the heatsink stays relatively cool.

So, I replaced it, and still doesnt have any green correction, but this time
the green STK gets too hot to touch in the matter of seconds, with or
without the conv yoke connected. rather odd, unless i got a dud STK.

any ideas? S-video works, so thats a good sign my comb is shot.
your missing either -28 or + 28 volts feeding the convegance amp you
replace most likely the - 28 with out the bias it will fry the amp
again look for one of the protection pico fuse open..
 
M

Mike

Jan 1, 1970
0
I just noticed after double checking and triple checking the Y/C seperator
module, I installed a new coupling cap on the YCE pin backwards. im sure
that wouldnt cause a totally black pic, but you never know.


what is YCE anyway. its got Y out, and C out, but whats YCE?
 
M

Mike

Jan 1, 1970
0
i switched it around, still dead video. i scoped my Y, YCE, and C out and
got nothing. but i got a video in pulse, and 9V at the comb. :-(

im assuming the MN8230 digital comb processor is fucked.
 
Top