Troubleshoot SMPS in Zenith TV...again!!!

[EJohnson]

Hello Everyone;

Once again I am still having trouble with a Zenith Model: A32B41
(9-2003) TV set...a wire-wound sand block? power resistor (5W, 0.68oh
RX3401) keeps burning up immediatly when the unit is plugged in. I go
the schematic and looked over the power supply section and the resisto
that connects to the bridge rectifier (DX3401) and supplies the groun
(-) is the trouble maker. This is the set that was killed by too muc
input voltage (240 not 120). I replaced some components including th
470uF (CX3405) main filter cap and couple other resistors. I don'
understand what keeps burning this resistor...any ideas???

Would the HOT (1167-01) be responsible for shorting the power resistor


Also, If you want to have the full (1MB) .PDF schematic for Zenith G
series, contact me through email and i'll send it to you.
Ejohnson1486(at)yahoo(dot)com
Thank You for any hel

 

[Tech Data]

Did you just forget to mention it or, didn't you change the regulator
and driver transistor yet? That resistor is a surge resistor and the
only thing from keeping the fuse from blowing. The reg. is an STR53041
and I forget the driver number except it's a Motorola. Also, there's a
100uf and a 22uf cap that needs changing and you're done. The other
components in the power supply should be just fine.

 

[Tech Data]

I think you can measure pins 3 and 4 for a short but, doesn't matter.
It's bad and so is the driver transistor and the two electrolytics.

 

[EJohnson]

Did you just forget to mention it or, didn't you change the regulator
and driver transistor yet? That resistor is a surge resistor and the
only thing from keeping the fuse from blowing. The reg. is an STR53041
and I forget the driver number except it's a Motorola. Also, there's a
100uf and a 22uf cap that needs changing and you're done. The other
components in the power supply should be just fine.

Hey, I pulled the STR53041 regulator off the board and the replacemen
.68ohm 5W power resistor didn't burn up this time...now, how do I tes
this STR53041 regulator? Just to make sure it is bad. I only have a
ohmmeter (AKA: multimeter) Thanks, Johnso