Emerson LCD TV/DVD combo DEAD

[[email protected]]

I have a one year old Emerson LCD TV/DVD combo model # LD200EM8
Dead set, I found AND replaced the following faulty parts in the SMPS
section:

*shorted MosFet switcher transistor on primary Q601 2sk3563
*shortet "fast" diode on secondary D901
*open line fuse 4 amp GMA
*shorted zener diode on primary D624 (39 volt, I think)

Note: It is hard to read the markings on the burnt zener D624, I
"think" it is a 39 volt zener, MTZJT-7739B, although it might be a 33
volt MTZJT-7733B instead, or something different, can anyone confirm
the correct voltage?

I have tried to power up the unit and NOTHING. None of the parts I
replaced were damaged, I have primary B+ but nothing else. What have
I missed on this single board chassis? Anyone having experience and
a diagram on this unit would be most welcome.
Any repair ideas from you smart people out there????
Common "dead set" issues with this unit? Help.
thanks,
electricitym

 

[Franc Zabkar]

I have a one year old Emerson LCD TV/DVD combo model # LD200EM8

Try this Funai service manual:
http://www.funai-corp.com/6pdf/sm/LD200EM8.pdf

This is the owner's manual:
http://www.funai-corp.com/6pdf/om/LD200EM8.pdf

- Franc Zabkar

 

[Arfa Daily]

I have a one year old Emerson LCD TV/DVD combo model # LD200EM8
Dead set, I found AND replaced the following faulty parts in the SMPS
section:

*shorted MosFet switcher transistor on primary Q601 2sk3563
*shortet "fast" diode on secondary D901
*open line fuse 4 amp GMA
*shorted zener diode on primary D624 (39 volt, I think)

Note: It is hard to read the markings on the burnt zener D624, I
"think" it is a 39 volt zener, MTZJT-7739B, although it might be a 33
volt MTZJT-7733B instead, or something different, can anyone confirm
the correct voltage?

I have tried to power up the unit and NOTHING. None of the parts I
replaced were damaged, I have primary B+ but nothing else. What have
I missed on this single board chassis? Anyone having experience and
a diagram on this unit would be most welcome.
Any repair ideas from you smart people out there????
Common "dead set" issues with this unit? Help.
thanks,
electricitym

Have you tried ESR checking all the electrolytics on the primary side ? Is
this a 'typical' LCD power supply that has effectively three SMPSs on the
same board ? ( PFC supply, standby supply and run supply) If so, is the
standby supply running ? I repair a lot of LCD switchers, and sometimes,
they can be very difficult to get going again. One little trick on an
'unknown', is to cast around on the 'net to see if there is a "PSU repair
kit" available for the model. If there is, it is often worth investing in
one, and fitting ALL of the parts which come with it, irrespective of
whether they look / read / don't seem to be faulty. Almost always, this will
result in a long term fix. By doing this, you eliminate the uncertainty of
interpreting 'ambiguous' markings on tiny surface mount components.

Most modern switchers are quite well behaved repair wise, when you fit a
genuine repair kit. After using such a kit, you can file away the parts list
that comes with it, and next time you get one in for repair, you can source
the individual parts cheaper than buying a kit.

Arfa

 

[b]

I have tried to power up the unit and NOTHING. None of the parts I
replaced were damaged, I have primary B+ but nothing else.

disconnect the secondaries on the psu transformer , see if the psu
comes to life.

chances are you have an open resistor somewhere near the MOSFET.

 

[[email protected]]

Try this Funai service manual:http://www.funai-corp.com/6pdf/sm/LD200EM8.pdf
This is the owner's manual:http://www.funai-corp.com/6pdf/om/LD200EM8.pdf
- Franc Zabkar
Please remove one 'i' from my address when replying by email.

-------------------------------------------------------------

THANK YOU everyone for the terrific and helpful information you
provided.... and Franc Zabkar, thanks for the link for the service
manual, most helpful as you can imagine. I will post another reply
when I get this unit repaired or if I am still having problems and
might need more good advice. thanks again.
electricitym

 

[[email protected]]

disconnect the secondaries on the psu transformer , see if the psu
comes to life.
chances are you have an open resistor somewhere near the MOSFET.

------------------------------------------

THANK YOU everyone for the terrific and helpful information and
suggestions that you
provided.... and Franc Zabkar, thanks for the link for the service
manual, most helpful as you can imagine. I will post another reply
when I get this unit repaired or if I am still having problems and
might need more good advice. thanks again.
electricitym