Samsung LE32R88BD/ BN44-00155A

[alvhann]

Re: Samsung LE32R88BD/ BN44-00155A

Take a pat on the back Mr retiredcaps.
Your observations appear to be correct in a round about way.

When you referred to BN44-00192A (instead of BN44-00155A)
I was puzzled and assumed you had got some threads crossed and took little notice of your comments.

I can know see I had posted the wrong image (of a BN44-00192A),
which I must have downloaded in my research. The two boards look remarkable similar, (maybe just a different Europe/ US designation}.

The point is, I decided to check the board again visually. I noticed a faint black line on the circuit board where the yellow adhesive fixes blue capacitor CM810,(44nf 1KV) to it.I figured that if this was some sort of leaky conduction path across the capacitor lead out wires it was capable of passing enough current to blow safety resistor RM801.

After chopping away a the adhesive and removing the capacitor I scraped away the (carbonated?) black line, (track). With capacitor reinstalled and a new resistor in place, TV was back in business. It's still early days yet, (two), but as the theory appears sound, I am quietly confident.

As an extra precaution, I have removed adhesive from around other components where a leaky path could develop.

Attachments show actual board BN44-155A and problem area before and after capacitor removal.

[budm]

Re: Samsung LE32R88BD/ BN44-00155A

Just another bad brown glue problems.
https://www.badcaps.net/forum/showthread.php?t=34692

[Alastair E]

Re: Samsung LE32R88BD/ BN44-00155A

The effects of this damned glue have been known for 20 years or more!

WHY do they keep using it!

[skywalker one]

Re: Samsung LE32R88BD/ BN44-00155A

Hello,
Thank you very much for all the information here.
Could you please tell me where I can purchase the RM801 resistor please?
What is the difference between a fusible resistor and a standard resistor?

Thank you very much

Paul

[repollo]

Re: Samsung LE32R88BD/ BN44-00155A

Hello, first time poster long time reader here, since yesterday I received a Samsung LCD TV with this power supply board. and for some kind of reason I don't seem to find what is wrong with it. Now I have decided to ask for some help after finding not a clue.

So physically the red led light from the front button switch flashes really consistently with no change, and if I depress it no voltages change on the Power Supply. There is no kind of damage whatsoever on the PS board, nothing burnt, fusible resistor is great. No swollen caps, still haven't got around making my own ESR meter to test them so no luck there until I build the meter. Nothing smells burnt either.

Electrically - Voltages are all over and I can't seem to figure out why since is everywhere.

S/BY jumper JP801 and JP807 are at +270V to +315V. (I think this is the same issue that shokat was trying to fix too.)
M_VCC is at -50V to -80V. This one is true for almost all of the IC's and transistors pins.

Everything at COLD side seems to be at 0V.

---OUTPUT---
ST-BY 5V pin 3 on CNW801 at 5V.
PS/ON 5V pin 1 on CNW801 at 5V.
+13V pin 7 on CNW801 at around +1V(maybe).(My multimeter isn't that great.)
+12V pin 19 on CNW801 at 0V.
+24V on CNM802 at 0V.

And lastly I can hear some really low whistling(high pitch noise humming), or some hissing, like something charging up and then discharges. I tried to use my oscilloscope but its just a sine wave and on its peaks there are some weird fast spikes going on which I haven't tried to decipher since I have a Tek 2225(analog scope).

Anyways, thanks for all the help you guys have provided since it has helped me understand power supplies a little bit better and all the info you can still provide its welcome. If you guys think I should post pictures, schematics or scope vids, let me know.

Thanks again,

Cheers,
Repollo

[repollo]

Re: Samsung LE32R88BD/ BN44-00155A

Hello again, just to give you a little bit more info, I noticed zener diode DZM854 27V 1/2W in the 24V rail shorted, replaced it and still shorted again. And have been trying to figure out why does it shorts with no results. Any thoughts? Please someone? Thanks in advance.

BTW: The information I provided earlier is almost all wrong since I was probing the HOT side of the board with respect to earth ground. So sorry for that, if someone could tell me how to edit posts I will greatly appreciate it.

EDIT: Just noticed my second post has an Edit button, but not the first one.

[stj]

Re: Samsung LE32R88BD/ BN44-00155A

a 1/2w zener can only handle 1/2w - obviously.
so see if there is something inline with it that would normally limit the current flow.
if it's 27v rated on the 24v line then it's probably a crowbar circuit to kill the supply if the voltage goes over 24v (well over 27v to be exact)
so maybe you should check whatever generates the 24v.

[stj]

Re: Samsung LE32R88BD/ BN44-00155A

o.k. i looked at the schematic.
i suspect you have a shorted diode.
check the 2 double-diodes on the heatsink that supply the 24v.
DM851 & DM852

[Agent24]

Re: Samsung LE32R88BD/ BN44-00155A

The effects of this damned glue have been known for 20 years or more!

WHY do they keep using it!

Then that's probably exactly why they keep using it - they know it will cause a failure and they hope you will buy the latest model thing when it does.

[repollo]

Re: Samsung LE32R88BD/ BN44-00155A

I checked those earlier but just to double check them here are some photos of curve tracer on them. They seem to be working properly, not shorted and show to be working like a diode on its respective polarities.

They read same value all around. So no shorts there.

1st anode to cathode on A diode

2nd anode to cathode on A diode

1st anode to cathode on B diode

2nd anode to cathode on B diode

anode to anode on A diode

anode to anode on B diode


Edit: Pictures got rotated by the forum server :/

[stj]

Re: Samsung LE32R88BD/ BN44-00155A

hmm - i never liked that type of testing.
if your sure then check the 2 1000uf caps.
if they are bad the zener will get hammered by high frequency spikes.

[repollo]

Re: Samsung LE32R88BD/ BN44-00155A

I'll need an esr meter for that then, can try it with the oscilloscope but won't be sure if they are starting to go, I have other caps to compare 'em but I don't think its a suitable way to test 'em. Any ideas on making a scrap-together-esr-meter?

Anyhow any other thoughts until I figure out the best way to test the caps?

And yes I need a new multimeter and a couple other testing equipment.
Thanks in advance.

[stj]

Re: Samsung LE32R88BD/ BN44-00155A

do a resistance test on the caps - they may be totally open circuit.

or just stuff a couple of 1000uf or a single 2200uf in for a test from something else.

[killaboona]

Re: Samsung LE32R88BD/ BN44-00155A

hi all

I have Samsung le32r88bd been switching it's self on/off for some time now finally the tv stopped working or should I say STUCK IN STAND BY MODE.

I have look at all the post in relation to this problem, I have changed all 13 caps although none of them had any visible damage but still changed them, also changed RM801 resistor as this was damaged with what I would say was a burn mark

I have also removed all visible brown/yellow glue tv still stuck on STAND BY MODE

any help would by welcome

[Agent24]

Re: Samsung LE32R88BD/ BN44-00155A

I have look at all the post in relation to this problem, I have changed all 13 caps although none of them had any visible damage but still changed them, also changed RM801 resistor as this was damaged with what I would say was a burn mark

Resistors don't burn up just by themselves. Verify that is is burnt and not just discolored from glue or heat etc. Check value, according to the schematic it should be 0.22 Ohms. if it is burnt out, check for other burnt components. Look at the schematic (page 2) since RM801 feeds QM801 and QM802, likely some component in that area also has issues.

[swhatszup]

Help - Samsung LE32R88BD/ BN44-00155A

Hi All,

I am new to this forum and attempting to repair a Samsung LN-T3253H with the BN44-00192A PWR SPLY. After visual inspection I had one bloated cap (2200uf-10v) and a glue short between RM801 and CM810. So far I have replaced (Caps -2200uf-10v, 2 x 1000uf 35v, 1000uf 25v, 470uf 25v, 1000uf 10v and RM801 resistor). The TV does not short of burn anything but sits there with the standby light blinking every once in a while...that's it. Should next step be to check the output voltages on the power supply pins. Should I have replaced CM810? Please advise. Thanks! Great forum...you guys rock!

Armand

[budm]

Re: Samsung LE32R88BD/ BN44-00155A

Are you getting steady 5.2V Standby voltage? You should take the voltage readings on the connectors when TV is turned OFF and when TV is turned ON. 192b SCH may be close enough to use for troubleshooting. C8100can be left out for now but should be replaced, the board can function without that cap.

[sordids999]

Re: Samsung LE32R88BD/ BN44-00155A

posting some pictures may help you further to fixing your problem

[selldoor]

Re: Samsung LE32R88BD/ BN44-00155A

deleted

[swhatszup]

Re: Samsung LE32R88BD/ BN44-00155A

Thanks for the advise Budm! I will check the voltages today or tomorrow. Busy schedule today.

Regards,
Armand