How to repair Power board BN44-00503A ?

[budm]

Re: How to repair Power board BN44-00503A ?

Pin 1 = 396v
Pin 2 = 13.64v
Pin 3 = 13.71
Pin 4 = 0v
Pin 5 = 13.77
Pin 6 = 13.77
Pin 7 = 14v
Pin 8 =
Pin 9 = 13.78
Pin 10 = 14.18v

That is not right, per spec pin 5 and 6 are GND pins.

[budm]

Re: How to repair Power board BN44-00503A ?

RM807 really shows 0.5 Ohms?
Pin 5 and 6 are returned to circuit through that RM807 so it should not have 13.77V on pin 5 and 6 unless the resistor has much higher than 0.5 Ohms. What Ohm scale are you using?
Has to be measurement error or that resistor is no longer 0.5 Ohms.

[Louis82]

Re: How to repair Power board BN44-00503A ?

resistor off the board measures 0.5v

[budm]

Re: How to repair Power board BN44-00503A ?

resistor off the board measures 0.5v

0.5 v?

[Louis82]

Re: How to repair Power board BN44-00503A ?

I have my meter on Auto Range. 0.5 . pics attached

[budm]

Re: How to repair Power board BN44-00503A ?

OK, solder the resistor back in place and measure the DCV between the two legs of that resistor to see if you get 13.77V per your earlier measurement.
BTW, as you can see, one end of that resistor is connected to the negative leg of the main filter cap which is the GND ref for the primary side, the other end should be connected to pin 5 and pin 6 (please verify that)

[flibby3655]

Re: How to repair Power board BN44-00503A ?

OT. In the second picture of post 25. Is that an acceptable way to remove one side of a component? Can one just solder the leg back together?

[Davi.p]

Re: How to repair Power board BN44-00503A ?

Post #12, Budm:
"I look at the board layout, without B13V present then you will not have B5V"
I can't see well this, i see 13v goes to a little double diode but is impossible to track paths for me... anyway to be sure that B13 and B5 v are working first is possible that pin ON-OFF from mainb. is active low then i think first one have to check optoisolator PC802 and RS852, or maybe force pin on-off low to test.

[budm]

Re: How to repair Power board BN44-00503A ?

Post #12, Budm:
"I look at the board layout, without B13V present then you will not have B5V"
I can't see well this, i see 13v goes to a little double diode but is impossible to track paths for me... anyway to be sure that B13 and B5 v are working first is possible that pin ON-OFF from mainb. is active low then i think first one have to check optoisolator PC802 and RS852, or maybe force pin on-off low to test.

PS-ON is fine because he is getting the 396V PFC Boosted Voltage as indicated in post 1.

[budm]

Re: How to repair Power board BN44-00503A ?

I have my meter on Auto Range. 0.5 . pics attached

I still wonder if your meter is showing 0.5 Ohms, 0.5 K Ohms, or 0.5 M Ohms.
13.77V on 0.5 Ohms resistor, that is LOTS OF CURRENT!

[Louis82]

Re: How to repair Power board BN44-00503A ?

Ok. No voltage between the legs of the resistor. And, here are the new readings Im getting for that IC: (I don't know why is different than the ones I gave you before, this is weird)

Pin 1 = 396v
Pin 2 = 0v
Pin 3 = 0v
Pin 4 = 0v
Pin 5 = 0v
Pin 6 = 0v
Pin 7 = 14v
Pin 8 =
Pin 9 = 0v
Pin 10 = 14.18v

[thoma]

Re: How to repair Power board BN44-00503A ?



Wait until Get Manual appears!!!!!!

[Davi.p]

Re: How to repair Power board BN44-00503A ?

Measure in diode test between pin 1-10 and 6-10 , one way and reversed probes, and report..

[Louis82]

Re: How to repair Power board BN44-00503A ?

Diode Mode
Pin 1-10
one way and reversed it measures 0 (no measure)
Pin 6-10
Black probe in pin 6, red in pin 10 = 0
Black probe in pin 10, red in pin 6 = 0.580

[Louis82]

Re: How to repair Power board BN44-00503A ?

Ok I replaced the IC and circuit board is working. I connected a LED strip I use for testing and it's on.
IC location ICM801 P#FSFR1700XCL.

One last question, May this IC be replaced with part # FSFR1800XCL. ?

[dskall]

Re: How to repair Power board BN44-00503A ?

Trying to modify led current. I believe R9113 is the CS sense resistor. But I've been wrong before

[budm]

Re: How to repair Power board BN44-00503A ?

Do you mean R9131, 3.5 Ohms, resistor?
Unless that IC has the LED current ref. pin for setting the current.

[dskall]

Re: How to repair Power board BN44-00503A ?

The .25 ohm off of CS pin

[budm]

Re: How to repair Power board BN44-00503A ?

I cannot really tell from the picture if it is 3.5 or 2.5 but it is R9131.

[dskall]

Re: How to repair Power board BN44-00503A ?

This schematic must be a little different. I have an R9120 that is 2 ohms and about 1 watt. Would that be the one to change/increase?