hantarex polo 28 blows fuse

[perjmolsen]

A new picture of the back pcb after I have cleaned it up and touched the solder points up.
Have i miss anything?

[perjmolsen]

Clearly I must have a short somewhere at the TP6 line...

Therefore I desordeled the new flyback completely, and removed it from the chassis, and removed the HOT (BU508A)
Now i have an OL between chassis and TP6 

And when i put the bulb between flyback pad (leg3) and chassis I get the bulbs ohms reading at 102.9 ohms - so thats all good..

BUT still fluxing volts when i test B+ 
Neckboard and yoke are connected to the monitor when testing

Have also tested with a new HOT in place, still OL in ohms reading and tp6 when bulb is disconnected.

If I turn the bulb out of its socket for a couple of seconds the volt rises to 90V but drops when i turn the bulb back in in order not to blow something up.
(If the bulb is disconnected for a long time the D116 gets hot and blow up)

So is it my transformer.. even that I am unable to measure some shorts between the coils, but if it where the transformer in my opinion, it would not be able to produce 90V without load..

[perjmolsen]

Close up at the back pcb - zener diode connection to transformator
I "think" that the two pads needs to be connected. When i remove the zener diode at do a connectivity test with my multimeter, there still are connectivity to the pad at the transformator.
The is missing a bit of one pad - where the one end of the 16 zener diode is solder in.

[princess prin prin]

The zener is connected to the gate of the mosfet and ground (the half ripped pad). The damaged pad is not to be connected to the pad next to it.

[perjmolsen]

Okay... well grantspain sad the same.. 

Then I  have to figure out why I get connectivity between the pads even with the zener out of its hole...hmm

I must say that both you and Grantspain know laot about chassis repair... THANKS for you help

[perjmolsen]

Hi

I have now removed the solder at the middle leg at the transformer - now there is NO connectivity between the two pads 
(only connectivity if i touch the pin)

So thinking to put in a new zener, test for connectivity between the pads.. then solder the pin in again, and test if that has done something good.. or i might have blown something up by bridging the two pads.

[princess prin prin]

You get "connectivity" because of the jumper. The jumper grounds one of the transformer's legs and the legs are connected together by the windings so yo'll always have "connectivity" across the half ripped pad (which is ground) and any of those three transformer's legs. If the zener is good and you can solder it reliably to that half pad, move on.

[perjmolsen]

Thanks!

I have tested the zener diode - it where fine.
Put it in and checked my soldering 
Even tried a new 18V zener. - but still the same...

[perjmolsen]

Hi

I refuse to give up 

I am still trying to get this chassis to work, it is NOT an option to give up.

The status is that I have tested all, and nearly replaced ALL components in the power supply part on this chassis, but when I put a 40W bulb on L103 the volt is pulsing.
I have also swapped out the transformer with one that i know its good.

If I disconnect the 40W bulb my 145V is present and stable
Also all the other volts are spot on.
TP10 = 11.7V
TP8 = 25V
TP9=16V
TP31=25V

But when I connect the 40W bulb the volts are pulsing, and I can hear a faint ticking sound, and then the two diodes D117 and D116 gets hot.
A small video with the 40W bulb connected:



What controls the feedback?