Bn44-00514a psu no stby

[budm]

Re: Bn44-00514a psu no stby

So is this RM806 burned up just like the other resistor we put a 43 Ohm in place of?

Yes you can, and then take the DCV reading between the two legs of the resistors so we can see how much current is flowing through them.

[krygods]

Re: Bn44-00514a psu no stby

I replaced RM806 and RM817 with 46 Ohm resistor and now RM882 is burning up and smoking when I plug in the TV

[krygods]

Re: Bn44-00514a psu no stby

Alright RM817 wasn't a 30 Ohm so i replaced that with the correct value. I replaced RM882 with a 46 Ohm and now nothing is smoking.

Across RM806 the DCV fluctuates from 0V to as high as 1.2V on and off over and over.

[krygods]

Re: Bn44-00514a psu no stby

Just checked again now across RM806 I have 9.1VDC

Still no DCV across the GATE and SOURCE of QM801

[budm]

Re: Bn44-00514a psu no stby

The Voltage between 'A' and 'GND' is 26V is fed by DM81, please check the Diode. 26V feeding the two 30 Ohms (RM882, 806) Voltage divider resistors, that is lots of current (0.43A). I wonder if they are really 30 Ohms resistors. It is either the Voltage is too high or the resistors are not the correct value.

'Just checked again now across RM806 I have 9.1VDC' that is almost 200mA! alomost 2W, RM806 is 46 Ohms, something is not right.

[krygods]

Re: Bn44-00514a psu no stby

is the Diode you are referring to DM831?? I don't see a DM81

[krygods]

Re: Bn44-00514a psu no stby

I have two other variations of this power board that are for 64" plasma but are the same.

I tested RM882 and RM806 on those other boards and they measure around 170 kOhm but are marked '300'

[budm]

Re: Bn44-00514a psu no stby

I have two other variations of this power board that are for 64" plasma but are the same.

I tested RM882 and RM806 on those other boards and they measure around 170 kOhm but are marked '300'

That made no sense either.

[krygods]

Re: Bn44-00514a psu no stby

I have two boards P/N bn44-00515a they are the same just different size panel.

Reason i mentioned is that i am able to test resistors from those other boards if i need to in order to determine what the values of the resistors are supposed to be.

So I tested those resistors that I assumed to be 30 Ohm with 300 marking and they measured at around 170kOhm

[budm]

Re: Bn44-00514a psu no stby

I have two boards P/N bn44-00515a they are the same just different size panel.

Reason i mentioned is that i am able to test resistors from those other boards if i need to in order to determine what the values of the resistors are supposed to be.

So I tested those resistors that I assumed to be 30 Ohm with 300 marking and they measured at around 170kOhm

That is I am not so sure if those resistors on the other board are also bad. We need working board or diagram to figure what is going on.

[krygods]

Re: Bn44-00514a psu no stby

Ok, I'll come back to this thread when I find a working board that we can compare to.

Thanks for the help thus far, I've learned quite a bit from this troubleshooting.

[f67bird]

Re: Bn44-00514a psu no stby

I have two other variations of this power board that are for 64" plasma but are the same.

I tested RM882 and RM806 on those other boards and they measure around 170 kOhm but are marked '300'

What you are looking at is most likely 30D
This is probably the EIA-96 marking system for 1% smd resistors.
EIA-96 code examples:


01Y = 100 x 0.01 = 1Ω
68X = 499 x 0.1 = 49.9Ω
76X = 604 x 0.1 = 60.4Ω
01A = 100 x 1 = 100Ω
29B = 196 x 10 = 1.96kΩ
01C = 100 x 100 = 10kΩ


more EIA-96 SMD examples...

01= 100 25= 178 49= 316 73= 562
02= 102 26= 182 50= 324 74= 576
03= 105 27= 187 51= 332 75= 590
04= 107 28= 191 52= 340 76= 604
05= 110 29= 196 53= 348 77= 619
06= 113 30= 200 54= 357 78= 634
07= 115 31= 205 55= 365 79= 649
08= 118 32= 210 56= 374 80= 665
09= 121 33= 215 57= 383 81= 681
10= 124 34= 221 58= 392 82= 698
11= 127 35= 226 59= 402 83= 715
12= 130 36= 232 60= 412 84= 732
13= 133 37= 237 61= 422 85= 750
14= 137 38= 243 62= 432 86= 768
15= 140 39= 249 63= 442 87= 787
16= 143 40= 255 64= 453 88= 806
17= 147 41= 261 65= 464 89= 825
18= 150 42= 267 66= 475 90= 845
19= 154 43= 274 67= 487 91= 866
20= 158 44= 280 68= 499 92= 887
21= 162 45= 287 69= 511 93= 909
22= 165 46= 294 70= 523 94= 931
23= 169 47= 301 71= 536 95= 953
24= 174 48= 309 72= 549 96= 976
Multiplier:
Z 0.001
Y or R 0.01
X or S 0.1
A 1
B or H 10
C 100
D 1000
E 10000
F 100000

So, 30D = 200k ohms

[budm]

Re: Bn44-00514a psu no stby

"I tested RM882 and RM806 on those other boards and they measure around 170 kOhm but are marked '300'" So may be it is 30'D', not '300'.

[pokepoke0610]

Re: Bn44-00514a psu no stby

I may or may not have a similar situation and have been reading this thread. I had originally made a post
called Samsung S64FH Sound but no picture. I had found that QS802 and QS804 were shorted. I bought the
replacement kit (which included those transistors) from ShopJimmy.com and have replaced those 2 MOSFETs.
I powered up my board (BN44-00516A) via a dim bulb fixture using a 100W light bulb. The light bulb did not
turn on which was a positive development. I have made the following measurements following the conversation
between budm and kyrgods
DC voltage across CP801, CP802, CP803 each measures 170V
DC voltage from "A" to GND: 25.5V
DC voltage from "B" to GND: 12.65V
DC voltage from "C" to GND: 12.65V
Resistance from "C" to GND: 130k and increasing
Gate to Source voltage on QM880: 7.4V
Gate to source voltage on QM801: 0V
Source voltage of QM801 to GND: 0V
I believe PS_ON measures 4.3V to GND (I made this measurement on the connector jumper labeled PS_ON)

I am trying to make sure that the power supply board is working properly (or as much as can be figured out) before
I reinstall it in the TV.

Any suggestions would be appreciated. Thank you.