Re: Samsung LE32R88BD/ BN44-00155A



Ah yes that would have been a better idea! I did think about that, but I've had no experience with them before and I wasn't sure if they turn into a total short, or they're still slightly resistive when they turn on? However, thinking about it, it would have been a problem since the resistors would have been there

Since I've lost the zenner, I'll have to wait for them to come in the post. Then I'll short the opto out. Thanks again!...

Re: Samsung LE32R88BD/ BN44-00155A

Sorry, not too sure what I meant to write there, but just to clarify:

I replaced the safety resistor and still had no 24v output. I then removed the zenner/diode/opto-coupler and biased the NPN with an external 12v and it now works.

So, it must be either the zenner/diode/opto-coupler that's failed

Re: Samsung LE32R88BD/ BN44-00155A

I thought I'd just let people know, in case it happens to them, but it seems like either my Zenner diode (ZDB805) or signal diode (DB804), or the opto-isolator (PC801S), failed. I removed the zenner (and unfortuanlty dropped, and lost it) and the signal diode, and biased the base of QB802 with an external 12V supply (I don't have a 15V) through a 2.2K resistor. I also removed RB808, so that I could apply 12V without the resistors affecting it and dividing it down.

Doing this worked! So, it seems, that the failure was in RM801. I replaced...

Re: Samsung LE32R88BD/ BN44-00155A

Sorry, what I meant was I put a resistor from pin 1 to pin 3, to try and emulate the on switch. However, j no longer have 5.2v on the standby windings, so I will have to take a look tomorrow, I don't have any more time tonight. I'll let you know my findings!

Thanks!

Re: Samsung LE32R88BD/ BN44-00155A

Thanks for the speedy reply!

Yes, the standby works and I do get >20v, 26.4v to be precise. I've tested the optocoupler off the board, by applying incremental currents to the led, and measuring the resistors which does decrease, so I think that's okay. But, as you mentioned, I don't get 15v on the emitter of QB802, however, I'm not sure what the ps_on is, is this the on/off pin (pin 3 of Cmn801?)

The zener and diode (zdb805 and db804) seem to be okay with a diode checker, likewise the QB802 is okay, so what could...

Re: Samsung LE32R88BD/ BN44-00155A

Hey guys!

I'm relatively new to bad caps, and to repairing consumer products.

I have the BN44-00155A board, with a blown RM801 resistor. The same story, glue everywhere, which after time.becomes conductive (I saw an EEVblog video a while ago with the same issue). I did find the problem before this forum, but after replacing the resistor with the closest value I had (0.7ohm) I still can't get it to work.

Here's a list of things I've tried, not exhaustive, butthe most relevant:

1) Dm831-835...