RCA no power indicator

[Minkota]

Re: RCA no power indicator

Measure the 12V pin also to see if it is showing 10V too.

It is showing 10v.

[Doc38343]

Re: RCA no power indicator

It is showing 10v.

Q12 on the back side of the board (great photo by the way) is blown apart.
or there is a piece of trash that looks like foil on the otherwise very clean looking board. Top right of photo near the bottom right of the center coil connectors... 2 up from D12

OOPS it is the TOP right of the center coil connections

[budm]

Re: RCA no power indicator

So to me without the main board connected you have PS-ON to turn on the 12V power supply and probably the switched 5V as well which means it has pull-up resistor for the PS-ON which is pretty rare for re-badged RCA TV.
It still does not make sense to me to have TWO separated power supply with low output Voltage, especially the 5v to run the main board.
Something is not making sense here at all.

[Minkota]

Re: RCA no power indicator

Q12 on the back side of the board (great photo by the way) is blown apart.
or there is a piece of trash that looks like foil on the otherwise very clean looking board. Top right of photo near the bottom right of the center coil connectors... 2 up from D12

OOPS it is the TOP right of the center coil connections

I see that now, I will see if I can do a continuity test later tonight and see if it is in fact burnt. I will also try to post a close up as well.

[Minkota]

Re: RCA no power indicator

Attached is a close up of the area in question....

[Minkota]

Re: RCA no power indicator

Attached is a close up of the area in question....

is it safe to assume this is most likely the cause of the issues?

[Doc38343]

Re: RCA no power indicator

is it safe to assume this is most likely the cause of the issues?

Hard to tell from photo could be trick of the lighting... you need to test the transistor... see if it is shorted to ground or shorted thru itself.

Something is cutting you voltage, but if it was a full short to ground it would either smoke and be obvious or just pull the rail to 0V.
I had a board once on a computer that had a low voltage issue and after many hours i found a shorted smd cap that was connecting a resistor to ground on a 3.3v line and the math for a voltage divider made it 1.2v and that would not let a mosfet trip on.
I don't know if that is your trouble just a possibility that is why it is hard to find.

That part looked completely blown in the other photo but not i'm not sure it may be ok just a lighting illusion... back to the testing board!! (sorry)

[Minkota]

Re: RCA no power indicator

Hard to tell from photo could be trick of the lighting... you need to test the transistor... see if it is shorted to ground or shorted thru itself.

Something is cutting you voltage, but if it was a full short to ground it would either smoke and be obvious or just pull the rail to 0V.
I had a board once on a computer that had a low voltage issue and after many hours i found a shorted smd cap that was connecting a resistor to ground on a 3.3v line and the math for a voltage divider made it 1.2v and that would not let a mosfet trip on.
I don't know if that is your trouble just a possibility that is why it is hard to find.

That part looked completely blown in the other photo but not i'm not sure it may be ok just a lighting illusion... back to the testing board!! (sorry)

I will be out of town for a week or two, I will continue testing then. Thanks for the help.