Sylvania LC320SLX No Power-Dead

[budm]

Re: Sylvania LC320SLX No Power-Dead

What do you get at pin 3 of T601?

[kevinm34232]

Re: Sylvania LC320SLX No Power-Dead

Think I may have found something. Figured I check this group of resistors.

R604 tests open
R605 and R606 test good .392-.395
R614 the large resistor test 0.000?

R604-606 RES CARBON FILM T 1/4W J 390k Ω
R614 METAL OXIDE FILM RES. 2W J 0.39 Ω

Could R604 be the problem? What about reading on R614?

[kevinm34232]

Re: Sylvania LC320SLX No Power-Dead

Let me resolder them and Ill check.

[kevinm34232]

Re: Sylvania LC320SLX No Power-Dead

What do you get at pin 3 of T601?

If I'm checking correctly 2.9v

[budm]

Re: Sylvania LC320SLX No Power-Dead

From the SCH, the line voltage is fed to L601, L602, then it goes to 4 Diodes D601~604 bridge setup, the + output feeds R602, 603, 617 then the output feeds pin3 of the T601.
So check all those connections of all those component, and the resistors.

[selldoor]

Re: Sylvania LC320SLX No Power-Dead

Also what would be a good resistor for discharging large capacitors? Or is there another way?

Modern capacitors have a resistor built in which normally discharges them in less than a minute. If you want to check to make sure just test the voltage with your meter - observe the polarity.

[tom66]

Re: Sylvania LC320SLX No Power-Dead

Modern capacitors have a resistor built in which normally discharges them in less than a minute. If you want to check to make sure just test the voltage with your meter - observe the polarity.

This isn't true... I know myself having touched plenty of caps and gotten plenty of shocks... They will self discharge slowly but it can take days.

[selldoor]

Re: Sylvania LC320SLX No Power-Dead

This isn't true... I know myself having touched plenty of caps and gotten plenty of shocks... They will self discharge slowly but it can take days.

Hmm? well I did say to check? - I do on BIG caps if im in a hurry and am pleased to say I have never been shocked at least not by a cap.

Anyway to answer the question as asked- it is all in here
http://www.repairfaq.org/sam/captest.htm#ctsdc

[kevinm34232]

Re: Sylvania LC320SLX No Power-Dead

This main on this cap definetely stays charged for awhile I found out when one of the pins touched the chassis

Anyway I heard about using a resisitor to discharge them, or a 100w light bulb, just curious what you all do..

Back to the TV as I said above, it seems R604 is bad although I haven't checked everything, could that one cause TV not to turn on?

[RON_CET]

Re: Sylvania LC320SLX No Power-Dead

yes if R604 is open it will stop set from powering ON, FYI i use a 680 ohm 1 watt to discharge most caps.

[kevinm34232]

Re: Sylvania LC320SLX No Power-Dead

OK Ill try that. Also Im curious why the large resistor (R614 METAL OXIDE FILM RES. 2W J 0.39 Ω) gives me a resistance reading of 0.000?

[RON_CET]

Re: Sylvania LC320SLX No Power-Dead

R614 if you are reading this in circuit your going to read just like short due to one side is connected to ground,but what i do is remove one side of R614 to read and you should get about .3 ohms also the zener diodes there D608,D610,D612 should not read shorted to ground in circuit

[kevinm34232]

Re: Sylvania LC320SLX No Power-Dead

I pulled 1 leg of all the resistors and R614 still read 0.000

[RON_CET]

Re: Sylvania LC320SLX No Power-Dead

how accurate is your dvm? also you do have a tolorance factor but either way you should read .39 ohms plus/minus i say 10% out of circuit

[kevinm34232]

Re: Sylvania LC320SLX No Power-Dead

Well now Im not sure how accurate it is, it's an Ideal Digital Multimeter, model ND 3267-1.
I'm definetely not getting a reading on that resistor but the other ones were very close so I don't know.

Maybe it is my meter the lower resistance ones seem to be the problem Ill have to try to change batteries first. In any case that one R604 is the only one that looks open so I will try replacing that and report back. Thanks!

[budm]

Re: Sylvania LC320SLX No Power-Dead

You know, pin 3 of that T601 was reading 2.9V as indicated in post 24, that power supply section is an always on, so if you got the shock from that large cap, then that reading of 2.9V cannot be right.

[RON_CET]

Re: Sylvania LC320SLX No Power-Dead

agreed budm cuase that voltage should be around 135 volts DC

[budm]

Re: Sylvania LC320SLX No Power-Dead

I have feeling his meter is not working right.

[kevinm34232]

Re: Sylvania LC320SLX No Power-Dead

You're right Bud but not my meter, the main fuse FH601 is blown, must have happened with the spark...

At Pin 3 of T601 get 166v

[kevinm34232]

Re: Sylvania LC320SLX No Power-Dead

You said I should be getting 135v is something wrong if Im getting around 165v which is what Im getting off of large cap?