Samsung Syncmaster 245BW

[Aruba]

Re: Samsung Syncmaster 245BW

You might want to check fuse FB802S if you haven't yet. It should be a 2A fuse.

The 5.2V standby output is developed using an Infineon IC controller ICE3B0365J at location ICB801S.

The 5.3V output is developed using a Sanken controller SI-8008HFE at location ICM852.

The 24V output is developed using a Fuji Electric controller F9222L at location ICM801S.

I also have one of these Syncmaster 245 for repair but the symptom on this one is flickering video. What I have found is that the 24V output is oscillating from 20-24V
when all 6 inverters are hooked up. If any one of the 6 inverter output harness is removed the 24V is stable. Appears the 24V output can longer supply the 3A as printed on the silkscreen on the solder side of the power supply board.
I removed the 5 wires that supplies the 24V from the power supply over to the inverter board and then hooked up a lab power supply set for 24V to the inverter board. Once the 24V on the lab power supply is turned on I can see the video is no longer flickering and the 24V is steady. The current meter on the power supply shows that it is supplying about 2.2A. This confirms the 24V converter is not operating correctly. To confirm this the 5 wires for the 24V output is connected to an electronic load and the load increased from zero to the 3A max. The output was only able to handle 1.6A when it went into current limit mode. I now need to determine if it is the controller F9222L or any component that determines the amount of current coming out of the power supply is at fault. I do not have a spare F9222L IC to try out though.
Once I figure out what is exactly the problem I will post it here.

[Aruba]

Re: Samsung Syncmaster 245BW

The voltage between pin 7 and pin 8 on the ICB801S is 15.5VDC on my unit.
The spec of this IC says that it could be anywhere between 10.3 to 26VDC.

[cloepula]

Re: Samsung Syncmaster 245BW

For the fuse i m not shure if i checked it, but i take alot of measurement on this board and only thing thet is working on this board is this unstable power supply on 5.2 volt section ic, other two ic dont get any power supply. This ic f9222L have two fet incorporated and one fet is possible to test because have all three pin comming out from ic, and testing this fet i noted thet is not blocking complitly when is discharged and the pin configuration for this fet is not like is in datasheet from fuji. You say thet on your 5.2 volt ic the supply is 15.5v and stabile without oscilation like on my ic?

[cloepula]

Re: Samsung Syncmaster 245BW

Ok. Checked fuse, is ok. still dont get answer from you about the voltages on ic. If is possible , check on dc and ac curent, because on my board there is somme ac curent to on this two pins.

[Aruba]

Re: Samsung Syncmaster 245BW

From your description you only have the 5.2V standby output. I have since figured out that you can't get the 5.3V output unless you also have the 24V output. The input of the 5.3V 8008HFE regulator is the main 24V so without it there won't be any 5.3V.
On my working unit except that the 24V output cannot deliver more than 1.6A,
I go these voltage measurements for you on the 24V Fuji Electric controller.
All the voltages is referenced to pin 8 on the IC which is primary hot ground
(as opposed to secondary ground). When making the voltage measurement on the IC please be careful with the meter probes and do NOT slip as the pins are
very close to each other and you do not want to short one pin to the other.
The F9222L IC has pins that are not populated and some that are cut. You still
need to count each pin# even though they might not be present. For instance the first three pins are not present but I still needed to count them starting from 1 to 3. The first pin available is pin 4.

All measurements referenced to pin 8 (ground):
Pin 4 - close to zero
Pin 7 - 19V
Pin 10 - 4.94V
Pin 11 - 1.26V
Pin 12 - 4.94V
Pin 13 - 3.03V
Pin 14 - 1.02V
Pin 15 - 4.93V
Pin 16 - 0.50V
Pin 23 - 391V

Remember these voltages are with the 24V output working so you should
get different measurements as your 24V output is not working.
See attachment for the pinouts for this Fuji F9222L controller.

[cloepula]

Re: Samsung Syncmaster 245BW

Thanks for this voltages, my ic f9222L have no voltage on it, all pins are completly without power, but i have a unstable voltage on ice3b0365J is going from 11v to 16v and fast changing 11, 14, 12, 16, 13, 15, 11, 14, and this is what i have on my board, and you say thet yours is 15.5 and not changing. Or maybe is changing to??

[cloepula]

Re: Samsung Syncmaster 245BW

And when measuring for ac curent on same ic, i have from 30v- to 35v changin on the same way.

[cloepula]

Re: Samsung Syncmaster 245BW

And my 5.2 voltage on boars, is unstable to, is changing fast from 4.8 to 5.3 volts.

[singlet]

Re: Samsung Syncmaster 245BW

Hi guys, I have 2 of these and one of mine has failed too. I was hoping that you might run through the process of opening the case without ripping it to pieces...

[cloepula]

Re: Samsung Syncmaster 245BW

Found smd component marked " br " on oposite side from f9222L just below. On internet found thet is a npn prebiased transistor. In my measuring with dmm one side is ok and other is open circuit. May be bad, will try tomorow to search in somme stores to find a replace and try to change it. Will post results tomorow.

[cloepula]

Re: Samsung Syncmaster 245BW

Component marked BR on power supply board, found open in one way and ok in other.

[mladen82]

Re: Samsung Syncmaster 245BW

Hi to all!
I have exact problem with Syncmaster 245B, model code LS24HUBCBQ/EDC
Power board: BN44-00173A
Standby voltage +5V is present but no main +5.3V and +24V for inverter
Stay tuned for problem seeking.

[Aruba]

Re: Samsung Syncmaster 245BW

Hi guys, I have 2 of these and one of mine has failed too. I was hoping that you might run through the process of opening the case without ripping it to pieces...

Attached are pictures of the tabs on the bezel you will need to pry and pass
them by to remove the cover. There are 6 of these tabs on the top and
bottom ends and 4 on each side of the monitor. I have a home made bamboo
tool I use to go around the periphery of the cover and bezel to snap each of
these tabs away from the cover one by one. Once all of them are off the
cover you should be able to remove the cover easily. You can use two flat
blade screwdrivers in a pinch to remove the cover. I usually start the opening
of the cover somewhere near the middle top or bottom side. Use one
screwdriver to hold the initial position and a second one to go around the
periphery of the monitor. Good luck.

[mladen82]

Re: Samsung Syncmaster 245BW

Y

The 5.3V output is developed using a Sanken controller SI-8008HFE at location ICM852.

I can't find that ic on my board!!!???

[mladen82]

Re: Samsung Syncmaster 245BW

Hello to all you guys !!
Me to trying to find the solution on same monitor, samsung syncmaster 245b. Simptoms are the same like yours here. When try to power on, only blue led on the on button lit blue. Monitor dont start, inverter dont start, but there is a 5.2v standby power. This is the only voltage from power supply. No 24v or 5.3v, Found burned resistor RB805 68ohm. All caps ok, tested with esr tester, and tested for capacity. Tested all other resistor, all found ok. When testing for voltages on vcc pin on ice3B0365J found strange voltage, 11v-16v dc fast changing values, testing for ac was 30v-35v on the same pin (. Tested diodes for vcc pin power and found all ok, then try to change this two diodes with similar, and again nothing, same strange and not stable voltages on vcc pin. Other two integrated circuit are without any power supply. Tested optoisolators , and all seams good. Tested all other diodes and rectifyers, and everithing seams ok, but power supply just dont start. So for now, only one resistor burned, and changed. Ordered new ice3b0365J for 5 euros and maybe in 2-3 days will arive. I dont know if this will fix the supply but i will try this solution, and if you didnt solve the bug on this monitor, and dont have any sugestion or news on your problem, wil change the ic and see if this was the reason for dead supply. Any sugestion or help is greatly apricieted.

I find burned resistor RB805 burned too.

[mladen82]

Re: Samsung Syncmaster 245BW

Component marked BR on power supply board, found open in one way and ok in other.

Its marked BQ on my board, QM802 and seems ok. It is probably NPN transistor.

[mladen82]

Re: Samsung Syncmaster 245BW

I shorted Stb +5V with PS_ON pin, so i can simulate Power On state.
I done some measurement, voltage on primary capacitor CP803 is 310V, so i assume PFC controller is not in working condition.
PFC controller is 4863G, VCC is 0V in Power On state, so PFC is not running.
Will continue to troubleshoot this.

[mladen82]

Re: Samsung Syncmaster 245BW

Ok, problem is solved with replacing burned resistor RB805 (temporaly with 45ohm).
Now i reading both main voltages +5.3V and +24V.
PFC was not in function because of open RB805.

Thanx cloepula for resistor

In for turn, i measure normal condition (PS ON) voltages VCC for IC's
VCC voltage on ICE3B0365J - 12,5V (stable)
on PFC 4863g - 15V (stable)

[cloepula]

Re: Samsung Syncmaster 245BW

Ok, Mladen, i ordered new F9222L, ICE3B0365J, and thet brnpn transistor, and tomorow will go to post office to pick them up. First will try to change only npn br, then if no result i will change both controllers and post here the results for further help to ours friend from forum.

all best....

[cloepula]

Re: Samsung Syncmaster 245BW

And for Mladen, must be som other thing bad on your monitor to, because this resistor is for protection, go on and test all caps with esr tester for hi esr.