LG 32le5300 with bad power supply (help)

[CapLeaker]

Re: LG 32le5300 with bad power supply (help)

Huh? Why doing that when you don't have any short there?

[Dannyx]

Re: LG 32le5300 with bad power supply (help)

Huh? Why doing that when you don't have any short there?

No worries - I wasn't gonna do that anyway, since I quickly remembered that upon shunting the relay, the bulb stayed off, so the caps were fine (unless they start experiencing breakdown under high voltage, which is just as unlikely).

[budm]

Re: LG 32le5300 with bad power supply (help)

No worries - I wasn't gonna do that anyway, since I quickly remembered that upon shunting the relay, the bulb stayed off, so the caps were fine (unless they start experiencing breakdown under high voltage, which is just as unlikely).

I am not really looking for shorted cap but shorted Load, and I still suspect something in the PFC IC, when you jump the relay but not applying the force on then there will be no VCC to feed the PFC IC so there will no bias Voltage to fed the GATE of the MOSFETS..
We still need to resistance betwen the VCC and the Gate drive of the IC.

[Dannyx]

Re: LG 32le5300 with bad power supply (help)

I am not really looking for shorted cap but shorted Load, and I still suspect something in the PFC IC, when you jump the relay but not applying the force on then there will be no VCC to feed the PFC IC so there will no bias Voltage to fed the GATE of the MOSFETS..
We still need to resistance betwen the VCC and the Gate drive of the IC.

I'll do that on Monday, since the board is at work and I don't work on Sundays

[Dannyx]

Re: LG 32le5300 with bad power supply (help)

I am not really looking for shorted cap but shorted Load, and I still suspect something in the PFC IC, when you jump the relay but not applying the force on then there will be no VCC to feed the PFC IC so there will no bias Voltage to fed the GATE of the MOSFETS..
We still need to resistance betwen the VCC and the Gate drive of the IC.

Just measured the resistance between VCC and GD: it's 5.3kOhms in both directions (that is, no matter how I connect my + - probes).

[Dannyx]

Re: LG 32le5300 with bad power supply (help)

I am not really looking for shorted cap but shorted Load, and I still suspect something in the PFC IC, when you jump the relay but not applying the force on then there will be no VCC to feed the PFC IC so there will no bias Voltage to fed the GATE of the MOSFETS..
We still need to resistance betwen the VCC and the Gate drive of the IC.

Bad news: replaced the PFC IC and the check lamp STILL stays on.....where the heck could this short be ? I've stripped down almost EVERYTHING ! The only thing left is the PFC coil....

[budm]

Re: LG 32le5300 with bad power supply (help)

I wonder if you change the 40W lamp to 100W lamp to see if it will still light up brightly or not. Did you use 40W lamp on other 32" TV before with just the power supply board by itself forced on but without loads connected?

[Dannyx]

Re: LG 32le5300 with bad power supply (help)

I wonder if you change the 40W lamp to 100W lamp to see if it will still light up brightly or not. Did you use 40W lamp on other 32" TV before with just the power supply board by itself forced on but without loads connected?

A 100w bulb obviously won't be AS bright, just because it requires more amps to flow through it, which in turn would make it more dangerous to the circuit. I've already packed up the TV and returned it as it was sadly, since the guy didn't want to wait any longer, so the only thing we can do at this point is speculate what could've been wrong with it. I've always used the 40W bulb, as it seems to be just the right value: neither too high nor too low. A 25w one would glow dimly even when the circuit is fine, while a 100w one might not come on even when a fault is present, plus it would allow more current to flow due to its lower resistance, possibly destroying something on the faulty circuit under test. Bottom line: 40w FTW ....too bad they're disappearing and hard to come by, with everything turning "eco, green" and shitty. Try that with a CFL....>_>

[Dannyx]

Re: LG 32le5300 with bad power supply (help)

I wonder if you change the 40W lamp to 100W lamp to see if it will still light up brightly or not. Did you use 40W lamp on other 32" TV before with just the power supply board by itself forced on but without loads connected?

Also, the answer to your last question is YES (have used it on just the boards - I never use the lamp on a fully assembled TV). I felt like I didn't really answer it in my long post

[CapLeaker]

Re: LG 32le5300 with bad power supply (help)

I use a 100W bulb nothing else.

[budm]

Re: LG 32le5300 with bad power supply (help)

I use a 100W bulb nothing else.

That is what I use also when testing just the board and no load.

[Dannyx]

Re: LG 32le5300 with bad power supply (help)

That is what I use also when testing just the board and no load.

Could also be because you're on an 120V line and you can use a lower series resistance to compensate....just a thought.

[addltd]

Re: LG 32le5300 with bad power supply (help)

Budm,

Did you get to a resolution on your powersupply fix for the LG 32LE5300? I have exactly the same CAP and fuse blown, but I don't want to start down the replace everything path. Did just the cap and fuse do the trick? Thanks!

[Dannyx]

Re: LG 32le5300 with bad power supply (help)

Budm,

Did you get to a resolution on your powersupply fix for the LG 32LE5300? I have exactly the same CAP and fuse blown, but I don't want to start down the replace everything path. Did just the cap and fuse do the trick? Thanks!

I eventually gave up on this one, but you might get away with applying power straight to the primary side with no PFC (that is, from the bride rectifier, you go straight to the reservoir caps and see if it turns on).

[addltd]

Re: LG 32le5300 with bad power supply (help)

Thank you!