LG 50PK350 Plasma

[tw2005]

Re: LG 50PK350 Plasma

LOL, you just answered previous post.

Not sure if it will damage it, they say

Note:
Always test the SMPS under a
load using the 2 light bulbs.
Abnormal operational
conditions may result if not
loaded.

I know I've had no issues with Panasonic PSUs with no load except my TV shutsdown with no load after 30secs but another model it just runs with correct output.

Ideally for a proper test a load would be better.

I guess you have no globes? Over here I think they are phased out.

[rigeback]

Re: LG 50PK350 Plasma

Yes I am going to look around for the hardware, the globes are going to be a problem as we only use the neon types here for low consumption.
Please have a look at since I cannot upload it, I'm not sure where to fix the ground wire that they indicate?

[tw2005]

Re: LG 50PK350 Plasma

I wonder if the logic board has an autogen.

They show it for the PJ350 but I see a spot it might be on the PK350 but no marking so would be reluctant to suggest it, other wise that would be a handy way to confirm the PSU

[tw2005]

Re: LG 50PK350 Plasma

Yes I am going to look around for the hardware, the globes are going to be a problem as we only use the neon types here for low consumption.
Please have a look at since I cannot upload it, I'm not sure where to fix the ground wire that they indicate?

I've got 50 and 42 guides, do you have the page number?

[tw2005]

Re: LG 50PK350 Plasma

if you're asking about grounding the globes, the tell you. Pins 1,2 Vsus, Pins 4,5,8 are gnd. i'd be soldering wires direct to the underside. This is at P812 on psu.

[rigeback]

Re: LG 50PK350 Plasma

I guess its on page 40 although so far I have found 3 X 60 WATT globes

[tw2005]

Re: LG 50PK350 Plasma

I guess its on page 40 although so far I have found 3 X 60 WATT globes

I'd run with that in series.

[rigeback]

Re: LG 50PK350 Plasma

Do you reckon it will be okay to the VS and VA independently because I've got add globes to get the 100W

[rigeback]

Re: LG 50PK350 Plasma

I wonder if the logic board has an autogen.

They show it for the PJ350 but I see a spot it might be on the PK350 but no marking so would be reluctant to suggest it, other wise that would be a handy way to confirm the PSU

I'll confirm this and I also noted:

To Test Control Board:
Disconnect all connectors. Jump STBY 5V from SMPS P813 Pin 13
to pin 3 (bottom leg) of IC231.
Apply AC and turn on the Set. Observe Control board LED D201, if it's on, most
likely Control board is OK.

However while the TV is working the green is also blinking which seems to suggest that the control is ok?

As for Static test I'll get the globes tomorrow, the PSU is back in the TV so the kids can watch TV for the weekend. Once it starts up we use the screen off energy saver otherwise its a pain to start again, possibly due to fact that the components are hot.

[tw2005]

Re: LG 50PK350 Plasma

I was not suggesting control board issue, looking for another way to run thePSU with a load with the mainboard isolated.

Interesting note about the energy saver? So what does that feature do?

[tw2005]

Re: LG 50PK350 Plasma

Do you reckon it will be okay to the VS and VA independently because I've got add globes to get the 100W

It does not mention Va, just a load on Vs. So once it's been running a while it just clicks if you turn off and try to restart?

Once on it stays on with no issues?

Starting from dead cold starts first time, every time?

[rigeback]

Re: LG 50PK350 Plasma

So once it's been running a while it just clicks if you turn off and try to restart?

Once on it stays on with no issues?

Starting from dead cold starts first time, every time?

Yes it seems to start much easier if the TV has been off or in standby for some time although it takes about 5 -10 times before the white screen comes out.

Once running its good no problems but if you shut down and try to restart it can become very frustrating because some times it continues clicking, restarting by its self and the best is to pull plug and wait.

[rigeback]

Re: LG 50PK350 Plasma

Yes it seems to start much easier if the TV has been off or in standby for some time although it takes about 5 -10 times before the white screen comes out.

Once running its good no problems but if you shut down and try to restart it can become very frustrating because some times it continues clicking, restarting by its self and the best is to pull plug and wait.

Interesting note about the energy saver? So what does that feature do?

This feature allows one to run the TV without a screen like a radio, there are 3 options of power saving for the TV depending on the input.

The input might have some thing to do with the problem I'm not sure, updates are supposedly updated through Digital Terrestrial antenna which I do not use. The other method is by USB which I have tried but indicates the firmware for the switch update is already up to date.

[tw2005]

Re: LG 50PK350 Plasma

That's a tough one to fault find. I read in one of the guides if the the power cable is removed from the main board and power is swithed on the TV starts by itself.

I wonder if it's worth checking that. maybe if it does, run the TV long enough for the clicking issue to start and retry it without the main, just not sure if the auto-gen needs jumping on the control board is required for the startup.

[tw2005]

Re: LG 50PK350 Plasma

This feature allows one to run the TV without a screen like a radio, there are 3 options of power saving for the TV depending on the input.

The input might have some thing to do with the problem I'm not sure, updates are supposedly updated through Digital Terrestrial antenna which I do not use. The other method is by USB which I have tried but indicates the firmware for the switch update is already up to date.

So heat may be a contributing factor but on what board, PSU or sustains?

very frustrating

[tw2005]

Re: LG 50PK350 Plasma

Ok, just found a training guide more useful and the PSU in the pictures will be yours as it has the same part number and has the 3 ceramic resistors you mentioned.

Also there is an auto-gen on the control board and was at the pads I suspected but is unmarked.

I'll upload it as an edit, about 18meg.

[tw2005]

Re: LG 50PK350 Plasma

having nothing but trouble getting this guide up.

I think we need to go back to TOM's post when he asked about AC DET.

that info looked like it was good I posted from the PJ350, but it's NOT.

I've been reading waiting to upload and in this it says.

AC Detection (AC Det) is generated on the SMPS, by rectifying a small sample of the A/C Line and routed to the Controller (IC701) where it outputs
at P813 pin 16 (4.06V) and sent to P400 to the Main Board where it is sensed and monitored by the Main Microprocessor
(IC701).
If AC Det is missing the set will not come on, the relays will click when RL_ON arrives, but then no other functions from that point.


Any time AC is applied to the SMPS, STBY 5V will be 3.49V and will be 5.13V when the set turns on.
AC DET WILL NOT be present until set comes on.
If AC Det is missing, the TV will NOT come on.

RL On is also quoted higher... 3.26V

this is what I copied from the other PJ350

Any time AC is applied to the SMPS, STBY 5V will be 3.46V and will
be 5.14V when the set turns on.
AC DET WILL NOT be present until set comes on.
If AC Det is missing, the TV will come on and shut off in 10 Seconds

[rigeback]

Re: LG 50PK350 Plasma

Thanks for the new training manual and trouble shooting help, yes it resembles this TV in many ways and RL_ON must have a problem because I measured only 2V on this line.
I will remove the PSU tomorrow for the static test and re measure all the points.
Or I could try run this auto-gen on the control board although still not sure how it really works.

[rigeback]

Re: LG 50PK350 Plasma

Well I eventually hooked up the globes in series although I had to use 2 sets to arrive at 100W.
Things are not looking good as the globes do not come on.
With Auto_Gnd connected to Ground the relay does not click on.
With 5V Standby to RL_ON there is no 17V out put.
With 5V line to M_ON M5V, VS and VA do not come on.
I personaly think RL_On has a problem on this board.

[rigeback]

Re: LG 50PK350 Plasma

Well I eventually hooked up the globes in series although I had to use 2 sets to arrive at 100W.
Things are not looking good as the globes do not come on.
With Auto_Gnd connected to Ground the relay does not click on.
With 5V Standby to RL_ON there is no 17V out put.
With 5V line to M_ON M5V, VS and VA do not come on.
I personaly think RL_On has a problem on this board.

After giving it some thought the test was better off with PSU connected to the TV, so replaced the PSU and spent half an hour click the remote and eventually she came on as usual, whilst trying to start up took some readings and it seems the fet with 12 V has a high degree of fluctuation during the relaying clicking, short spikes that reach over 100V, maybe this is tripping the safety system on PFC into not starting??
Rest of the readings all read good apart from RL_ON line which come and goes during the relay start up, on the hot side there 400V.