philips 14gr1236 -- flyback keeps blowing
 

tv was humming when it come for the first time. I cheked psuply,
capacitors, diodos , chokes near flyback, and evertything seems ok. I
checked diodes for leaking, but they tested ok.
so i replaced the flyback, it had shorted pins 1-10. the new one
at2079, lasted 1 second and blows again. Pins 1-10 shorted again. I
checked evertything again. What am i missing? I thought flyback was
defective so i try with a hr7527, but same thing. crt? socket?
any ideas!?
thanks?

philips 14gr1236 -- flyback keeps blowing
 

On Jul 20, 7:40 pm, aldo wrote:
tv was humming when it come for the first time. I cheked psuply,
capacitors, diodos , chokes near flyback, and evertything seems ok. I
checked diodes for leaking, but they tested ok.
so i replaced the flyback, it had shorted pins 1-10. the new one
at2079, lasted 1 second and blows again. Pins 1-10 shorted again. I
checked evertything again. What am i missing? I thought flyback was
defective so i try with a hr7527, but same thing. crt? socket?
any ideas!?
thanks?

You had a problem...you replaced some defective parts, but
did not identify the actual cause of the problem, you missed at least
one other defective part.

How are the parts that you replaced? Did you use the correct parts
when you replaced them? What test equipment do you have?

What do the waveforms look like when controlling the current?
What are the voltages going to the flyback?
What do you mean by blows again?
What are pins 1 and 10, primary, secondary, HV windings?

Why not post the results of standard horizontal output/flyback
troubleshooting rather than just the results of throwing the same
parts at the problem.
Some basic troubleshooting will probably save you much time and wasted
parts.

philips 14gr1236 -- flyback keeps blowing
 

wrote:
On Jul 20, 7:40 pm, aldo wrote:
tv was humming when it come for the first time. I cheked psuply,
capacitors, diodos , chokes near flyback, and evertything seems ok. I
checked diodes for leaking, but they tested ok.
so i replaced the flyback, it had shorted pins 1-10. the new one
at2079, lasted 1 second and blows again. Pins 1-10 shorted again. I
checked evertything again. What am i missing? I thought flyback was
defective so i try with a hr7527, but same thing. crt? socket?
any ideas!?
thanks?

You had a problem...you replaced some defective parts, but
did not identify the actual cause of the problem, you missed at least
one other defective part.

How are the parts that you replaced? Did you use the correct parts
when you replaced them? What test equipment do you have?

What do the waveforms look like when controlling the current?
What are the voltages going to the flyback?
What do you mean by blows again?
What are pins 1 and 10, primary, secondary, HV windings?

Why not post the results of standard horizontal output/flyback
troubleshooting rather than just the results of throwing the same
parts at the problem.
Some basic troubleshooting will probably save you much time and wasted
parts.

B+ es about 8V
i have checked b+ caps and they are ok
i desoldered b+ pin on flyback and still the same b+ voltage
I mean pin 1 and 10 on flyback transformer windings.
give me some hint about basis troubleshooting, 'cause i am a
starter....

philips 14gr1236 -- flyback keeps blowing
 

On Jul 21, 1:24 pm, aldo wrote:
wrote:
On Jul 20, 7:40 pm, aldo wrote:
tv was humming when it come for the first time. I cheked psuply,
capacitors, diodos , chokes near flyback, and evertything seems ok. I
checked diodes for leaking, but they tested ok.
so i replaced the flyback, it had shorted pins 1-10. the new one
at2079, lasted 1 second and blows again. Pins 1-10 shorted again. I
checked evertything again. What am i missing? I thought flyback was
defective so i try with a hr7527, but same thing. crt? socket?
any ideas!?
thanks?

You had a problem...you replaced some defective parts, but
did not identify the actual cause of the problem, you missed at least
one other defective part.

How are the parts that you replaced? Did you use the correct parts
when you replaced them? What test equipment do you have?

What do the waveforms look like when controlling the current?
What are the voltages going to the flyback?
What do you mean by blows again?
What are pins 1 and 10, primary, secondary, HV windings?

Why not post the results of standard horizontal output/flyback
troubleshooting rather than just the results of throwing the same
parts at the problem.
Some basic troubleshooting will probably save you much time and wasted
parts.

B+ es about 8V
i have checked b+ caps and they are ok
i desoldered b+ pin on flyback and still the same b+ voltage
I mean pin 1 and 10 on flyback transformer windings.
give me some hint about basis troubleshooting, 'cause i am a
starter....


this is excellent step by step for beginners:

http://www.highlandelectrix.fsnet.co...ir/repair.html
and the tv section of www.repairfaq.org

It is rare for the flyback to short out suddenly like that. the
horizontal transistor usually goes first.
firstly remove the horizontal transistor and place a 60w bulb across
c-e. measure the b+.

test the horizontal transistor. depending on the problem you may need
to change: Horiz. transistor and the cap across it's c-e terminals.
use exact replacement.

you might want to disconnect secondary loads like the RGB or audio
stages to help narrow down the fault.

-B.