Philips magnovox projection TV dead now

[Mike]

The guy forgot to hand me the the paper with the model number written down,
so im not sure what it is, but i got the sweep/power module here.

it was a 1997 model thats 53 or 54 inch.

The model number of the sweep board is APD008B002 GR7D LARGE SIGNAL.

Anyway, back to the problem.

everything was working just fine, but the glycol was shot. So everything was
going smooth, cleaned the CRTs and changed the fluid.

I had to fight to get the HV wires back in the splitter which is mounted on
the board.

I went to power it up, everything fired up at first, then the HV charged up
the CRTs. at that second i heard a couple of HV arcs from the splitter
vicinity and it powered down. I had this happen lots of times when the wires
arnt seated all the way.

Thats when i relized one of the HV wires curled up and didnt go in the hole.

so i fixed it, but now its too late. For some strange reason, the set is now
dead. no power, no startup, nothing. ARGH. the only set i had do that too.

I checked all the usuals, the fuses, all the inline circuit fuses, I check
the HOT and the HV output transistors, those are fine. All the diodes, i
checked the chopper transistor. Everything. I cant find anything shorted or
bad. checked all resistors. hmmmmm....

the chopper just dont want to start up. I removed the HOT out of circuit, no
difference. the system draws power when plugged in, but the power supply no
longer "chirps" when plugged in like it used to. I tested for the 5 and 15v
standby, they are present. but no other voltages are. (chopper not running).

so now, im screwed, and dont know what went wrong in the circuit.

Any ideas?

 

[Mike]

i just called him. its a PTV775. i was close though. hehehe

 

[Mike]

JUST HIT ME. PTV730. hehehe

 

[Motorman]

Here some tips from repair world hope they can help:
TELEVISION magnavox ptv 775-ah01 picture dark only red on screen. all tubes
were lit changed fluid in both green and blue. Now good picture.
TELEVISION Magnavox 7P6033W101 PTV775AH01 Q802 HOT shorts intermittently
C811 part #202055890481 330pf 2kv Ceramic TELEVISION PHILIPS PTV775 Q802
Shorts once in a while. HV arc from anode to yoke. Run a 306 degree bead of
silicon around anode cup.
TELEVISION Phillips ptv775 OSD green instead of blue ic600 defective
TA8845an=483520988331
TELEVISION Philips ptv775 Flashes green during channel change ic600
defective ta8845an=483520988331
TELEVISION philips ptv775 No convergence menu set-up IC 600 defective
ta8845an=483520988331
TELEVISION Magnavox PTV775 service info similar to ptv770. philips service
manual #7566
TELEVISION NAP PTV775 Dead Set - Only power led light comes on IC600 and
IC400 on Small Signal Board - 12V Source IC600


Motorman

 

[Mike]

I was over at repairworld. nothing usefull.

 

[Mike]

Where can I get IC401 IC402? or the info on them to test them? im thinking
those are bad.

 

[Mike]

there is definately an overload in the power supply somewhere.


The standby supply was running, I removed both HOTs and for the hell of it,
i removed the drive from the standby FET, and put it on the main fet, so the
standby osc would start the main supply.

So, it pulsed up, and blew the fuse off the main FET, and thats most likely
because of an overload. But both hots are removed, and I statically checked
all the secondary diodes. What else is there?

 

[Mike]

nevermind. I found a service manual and determined IC402 to be shorted.