DX-L32-10a won't power on stuck in standby

[2smoovedaddy]

All voltages are good 5,12,24. C610,C611,N603 on the right side of the board in the pic of the main board are getting extremely hot to touch. Any ideas. There's no picture standby light is on but nothing when power is pressed. I've went through another post on here of the same exact model and tried all those things. Thanks!

[2smoovedaddy]

Re: DX-L32-10a won't power on stuck in standby

Tv is Dynex by the way.

[retiredcaps]

Re: DX-L32-10a won't power on stuck in standby

1) Did you change the capacitors on the power board? It is strange to see Rubycon caps (quality) mixed in with Changex? (crap).

2) Measure your voltage regulators to see if they are within specification (see below).

[budm]

Re: DX-L32-10a won't power on stuck in standby

Those two caps should never get hot to touch at all unless the N603 (NUMBER???) gets so hot that it heats up that area. You should get the voltage reading on the caps and on all 3 pins of that N603.

[2smoovedaddy]

Re: DX-L32-10a won't power on stuck in standby

Thanks RetiredCaps and Bud. N602,603,604 are hot as hell as are the caps surrounding them. I need a little help interpreting these voltage regs. N603 is AZ1117D 3.3EI and it looks good. The other 2(n602,604) are 1117L and I looked at the data sheet but i was lost. Heres the readings.

N602 N603 N604
1)2.01V 1)0V 1).5V
2)3.25V 2)3.31V 2)1.78V
3)5.29V 3)4.95V 3)3.30V

Voltage Across
C610=4.96V
C611=3.30V
C621=3.32V

Thanks for your help.

[2smoovedaddy]

Re: DX-L32-10a won't power on stuck in standby

Bump

[budm]

Re: DX-L32-10a won't power on stuck in standby

The Voltages of the regulators are normal, still the caps should not be hot at all, something does not make sense yet, those cap should be bulging right now with that much heat.

[2smoovedaddy]

Re: DX-L32-10a won't power on stuck in standby

Thanks BundM. Just an update. We pulled the N603(AZ1117D3.3ei) and now none of those caps get hot. Could that be the problem.

[2smoovedaddy]

Re: DX-L32-10a won't power on stuck in standby

bump

[2smoovedaddy]

Re: DX-L32-10a won't power on stuck in standby

bump

[budm]

Re: DX-L32-10a won't power on stuck in standby

OK. for the regulator to get that hot and causes the surrounding component to get hot also, it means that too much current is flowing through the regulator. But I do expect the regulator to go into shut down mode. Not sure what else to tell you at this point.
You can take the resistance reading between chassis ground and each pad of the regulator to see if the output is feeding the current into really low Ohm.

[tom66]

Re: DX-L32-10a won't power on stuck in standby

If the regulator is oscillating, the capacitors will get hot.
The regulator can oscillate if the capacitors on the output fail.

[budm]

Re: DX-L32-10a won't power on stuck in standby

Thanks, Tom, I forgot about that, may be he should replace the caps for the input pin and the output pin at the same time. He does not have the scope to look for the oscilltion, so replacing caps may be the easiest thing to do.

[tom66]

Re: DX-L32-10a won't power on stuck in standby

Also, usually (not always) when the regulator oscillates, the output will be a little low, maybe 5% or so. Most LDOs are 1% or 2% grade.

[2smoovedaddy]

Re: DX-L32-10a won't power on stuck in standby

Thanks guys replaced N603 and no go. N604 gets hot as sh*t as does c10 and c11. Whats the easiest way to remove those smt caps on the input/output. Tried an iron but no go. Also emailed Dynex for a schematic. Thanks!

[budm]

Re: DX-L32-10a won't power on stuck in standby

But you did not replace the caps, the circuits will oscillate if the filter caps are bad a s Tom has pointed out.