Hantarex Polo 25 R255 burnout why?

[Triple3Fast]

Changed the HOT and it worked!

 

[mecha]

Changed the HOT and it worked!

there's that array of poly block caps in front of the HOT, you need a secret decoder ring to figure out what their values are, but as those go out of whack it can lead to premature HOT failure later.

at least your HOT's demise was done at your own hands!

 

[Triple3Fast]

Agreed. I just ordered a few of the poly caps to be extra safe down the line.

 

[Triple3Fast]

Pulled one poly cap (c172) and it had a crack in it!

 

[Ohmerone]

Pulled one poly cap (c172) and it had a crack in it!

Often they are Bulged on the sides as well.

One or two is more likely then the others around it.

If you really what to know who does what and after your done

add one back at a time and you can see a symptom with each one

or you can go my experience and just swap them out and don't test nothing.

A flyback can not control the size of the drive pulse and larger it is the higher

the secondary voltages can get, there fore rising the voltages off the secondary

which lead to other circuits and supply voltages are what get messed with

so restoring the circuits will eliminate hours of troubleshooting why parts are burning

for no good reason.

There are a few symptoms but all lead to poor high voltage regulation

as well as Power supply regulation.

If you O-scope the H.O.T collector your see the changes in the pulse

and when it P~P levels increase and shape of waveform because of the

Polys and in extreme case's it kills the damper and modulation diodes.

you could wait till that happens if you like, to validate replacing parts around it

also.