Samsung 930b LCD cold start problem (inverter?)

[rico_st]

Re: Samsung 930b LCD cold start problem (inverter?)

I believe that's a BIT3195 or BIT3195G.

PlainBill

It is BIT3195G

[PlainBill]

Re: Samsung 930b LCD cold start problem (inverter?)

I am unable to find a data sheet on the controller; if a data sheet could be located it should be very easy.

I believe that's a BIT3195 or BIT3195G.

PlainBill

[alexanna]

Re: Samsung 930b LCD cold start problem (inverter?)

Hi!
Im not very good in electronic to track it to the controller.
Not shure but i think writes something like BIT31956 FMF17 60511

I am unable to find a data sheet on the controller; if a data sheet could be located it should be very easy.

[rico_st]

Re: Samsung 930b LCD cold start problem (inverter?)

It would be a good idea to see if the BL on/off voltage is making its way down to the backlight controller, and it is the correct voltage.
Can you read a number on the 16 pin back light controller?

Hi!
Im not very good in electronic to track it to the controller.
Not shure but i think writes something like BIT31956 FMF17 60511

[alexanna]

Re: Samsung 930b LCD cold start problem (inverter?)

Ok!
I conected videoboard and power board (without lamps and panel) video cable to pc and turn on pc and monitor and measured On/Off 2.37v, A-Dim 0.01v.
Is that ok?

It would be a good idea to see if the BL on/off voltage is making its way down to the backlight controller, and it is the correct voltage.
Can you read a number on the 16 pin back light controller?

[Rtech]

Re: Samsung 930b LCD cold start problem (inverter?)

Waste of money if its the Backlights !!!!

[rico_st]

Re: Samsung 930b LCD cold start problem (inverter?)

No luck
I will risk 20$ and buy new(used) power board on ebay.
Thanks!

[Rtech]

Re: Samsung 930b LCD cold start problem (inverter?)

Well, looks like Last Chance Saloon,before the Backlights become the Main suspects,so I would resolder the Inverter transformers,and all other joints between the secondary and the Lamp sockets,eg the small Blue Caps etc etc.

[rico_st]

Re: Samsung 930b LCD cold start problem (inverter?)

Thanks for yor effort helping me.
I measured resistance in transformers secondaries (onboard) and they are similar. 1.32 and 1.35. They are ok? What else to check?

[Rtech]

Re: Samsung 930b LCD cold start problem (inverter?)

Maybe, but measure the resistance of the secondaries of both of the Inverter transformers, they should be very very similar measurements.

[rico_st]

Re: Samsung 930b LCD cold start problem (inverter?)

No problem, the Dim voltage varies depending on where the OSD level is set, BUT the on/off voltage should have turned the Lamps on, so plug them in....

Nothing
Still no backlight. Lamps are gone?

[Rtech]

Re: Samsung 930b LCD cold start problem (inverter?)

Ok!
I conected videoboard and power board (without lamps and panel) video cable to pc and turn on pc and monitor and measured On/Off 2.37v, A-Dim 0.01v.
Is that ok?

No problem, the Dim voltage varies depending on where the OSD level is set, BUT the on/off voltage should have turned the Lamps on, so plug them in....

[rico_st]

Re: Samsung 930b LCD cold start problem (inverter?)

Ok!
I conected videoboard and power board (without lamps and panel) video cable to pc and turn on pc and monitor and measured On/Off 2.37v, A-Dim 0.01v.
Is that ok?

[Rtech]

Re: Samsung 930b LCD cold start problem (inverter?)

The A-Dim and On/Off are supplied by the video board,so you need to,have it connected to the PSU/Inverter,and then you need to arrange the Monitor to be switched on,with the VGA lead connected and your PC switched On.There are other ways but this is maybe the best way for you.When your Front panel lamp shows the PC signal has been recognised, then you should be able to measure the A-Dim and On/Off voltages.

[rico_st]

Re: Samsung 930b LCD cold start problem (inverter?)

Measure the ON/OFF and A-DIM pins on the connector. ON/OFF should be about 3.3 volts, A-Dim will probably be lower, around one volt. If these are correct, trace the signals from the connector to the inverter controller. Check for proper voltages at the inverter.
......
PlainBill

Hi!
My knowledge about electronic isn't too good but i measured it on the back of the board. On/OFF 0v, A-dim 0v, 5v and 13 are ok.
(i measured it without connected videoboard?)
Here are pics of the back.

[PlainBill]

Re: Samsung 930b LCD cold start problem (inverter?)

Hi!
Problem is that backlights arent working at all.Power light is on. I replaced 3 bad CapXon 820uF 25v caps with 1000uF 35v and others 2x100uF16v,1x330uF 16v, 1x10uF 63v, 1x47uF 63v. I replaced them with new "JAMICON" caps. Replaced picofuse with litle wire.You can see picture but still no backlight. Where else to look?
Thanks!

Measure the ON/OFF and A-DIM pins on the connector. ON/OFF should be about 3.3 volts, A-Dim will probably be lower, around one volt. If these are correct, trace the signals from the connector to the inverter controller. Check for proper voltages at the inverter.

Tip: You gave us good pictures of the top of the board. An equally good picture of the bottom would help us help you.

Tip 2: A fuse is placed in a circuit to protect components in case of an overload. Substituting a wire for a blown fuse without verifying the cause of the blown fuse has been eliminated often leads to more expensive and expensive repairs.

PlainBill

[rico_st]

Re: Samsung 930b LCD cold start problem (inverter?)

Hi!
Problem is that backlights arent working at all.Power light is on. I replaced 3 bad CapXon 820uF 25v caps with 1000uF 35v and others 2x100uF16v,1x330uF 16v, 1x10uF 63v, 1x47uF 63v. I replaced them with new "JAMICON" caps. Replaced picofuse with litle wire.You can see picture but still no backlight. Where else to look?
Thanks!

[Rtech]

Re: Samsung 930b LCD cold start problem (inverter?)

More detail on 'problem with Backlight', would certainly help,to allow members to maybe help you,eg None work,they work sporadically, they go on and go off BUT Power light stays on etc etc etc.

[rico_st]

Re: Samsung 930b LCD cold start problem (inverter?)

Hi to all!
I have Samsung 930BF and have problem with backlight. I replaced all caps and picofuse but still no backlight. Any idea where else to look?
Here are pictures of my board.
Thanks!

[Logicsays]

Re: Samsung 930b LCD cold start problem (inverter?)

Well, I'm no expert on electronics. I learn quickly but I was following this thread from the start and i replaced the caps. Others mentioned the fuse being problematic so I was looking for it to test it.

I did the whole power on and check with a flash light. I see the image so something is working right. I still will take some pics if I ever get some time.. been really busy fixing computers.

I think I found the fuse under a glob of rubber stuff. I'm going to check it out and see if its tests good. A friend of mine repairs defective Toyota ECM's so I might have an in on some help.. lol