Logik l32digb20

[tom66]

Re: Logik l32digb20

yes i forgot sorry pin 1 going from the left of the regulator is
PIN 1 5.15 Volts
PIN 2 3.26 Volts
PIN 3 2.02 Volts

That part is working. Pin 2 OUT minus Pin 3 ADJ = 1.25V reference, so it is working fine.

You should try loading the PSU with bulbs as previously suggested before needlessly replacing parts. It will save you money and time and help in narrowing down the cause.

BudM has some photos of jigs he builds I seem to recall one was using car headlamps as a load as they are an inexpensive and high power load. Obviously not as good as a precision load tester, but it's a good substitute for basic tests.

Board returns are the reason I only ever sell parts to trusted badcaps.net members. Otherwise, it's too much hassle. I have so many to sell. All in known good or known bad condition.

[flocko]

Re: Logik l32digb20

I had the understanding that if this was an adjustable regulator Pin 1 5.15v Pin 2 3.26v Pin 3 2.02v Pin 1 5.15v +1.25v = Pin 2, if it were a 1117 33 it would be fine? but as yet we dont have the part number Flocko

[sordids999]

Re: Logik l32digb20

Bm1084 adj 1006tq

[tom66]

Re: Logik l32digb20

Output for MOST (not for all, but 1084 and 1117 types it is) is the middle pin. Input is pin 1, adjust or ground is pin 3.

[flocko]

Re: Logik l32digb20

So Tom are you saying that Retiredcaps how to test a voltage regulator is wrong ? and should not be followed ? so on a 1084/1117 ADJ regulator the 1.25v reference is between Pin 2 and pin 3 not as he tells us Pin 1 and Pin 2 Flocko

[tom66]

Re: Logik l32digb20

Pin 1 and pin 3 might be reversed order -- it depends on how they are numbered! But the lowest voltage is adjust, second lowest / middle voltage is output, highest is input.

A vreg can only drop voltages. It is a linear device. It cannot increase output voltage given any particular input voltage. It also must have about 1V or more between input and output to regulate correctly (the drop out voltage.)

If unsure, it never hurts to check the datasheet. 1.25V = Out-Adj.

[flocko]

Re: Logik l32digb20

Sorry Tom so Sordids 999 dont know his left from his right my mistake, i did not think of that?

[tom66]

Re: Logik l32digb20

I think it's more likely his pin 1 is different from the pin 1 you or I are assuming...

[flocko]

Re: Logik l32digb20

hi Tom had a look at the data for BM1084 ADJ and Pin 1= ADJ= 5.15v
Pin 2= V out=3.26v
Pin 3 =V in=2.02v
he tells us he read from left to right so some thing wrong here and if the readings on the other regulator on page one is correct then two regulator need replacing the one over the top of the 1117 33 and the BM1084 ADJ at the bottom Flocko

[tom66]

Re: Logik l32digb20

I'm following what's most likely. Input always less than output. It can NEVER be more than the input voltage. LDOs can't increase output voltage for a given input. Therefore, the pins are being counted differently. Most likely counted back to front.

[flocko]

Re: Logik l32digb20

And now he has gone all quiet on us ? but i never say never as it has a tendency to bite you on the arse Flocko

[sordids999]

Re: Logik l32digb20

Sorry been busy So shall i order the two regulators ?

[flocko]

Re: Logik l32digb20

Sorry I think you should recheck the regulators again as Tom thinks you have them wrong with the pin numbers? so if you could do them as before and mark them on photo and can you tell us the part numbers as well Flocko

[tom66]

Re: Logik l32digb20

Perhaps best to go over all the readings again?
But in my opinion it's either the PSU, then bulbs or panel-frame arcing, in that order.
A PSON check would rule the main board out completely - you can see PSON marked on bottom of PSU board.

[flocko]

Re: Logik l32digb20

With the set i worked on only last week i had PS on, 24v to inverter but no BL on from the AV and was told that before it failed the screen would flash on and off, then the backlight failed to come on at all and the set would only turn on from the side buttons and remote but not off, fault was the 3.3 regulator on the Av main board. so far he has had the side buttons fail to work and also the remote, the regulators on the main are not right, how would the PSon supply show it not to be the mainboard?

[sordids999]

Re: Logik l32digb20

ok hope you can see the pictures with everything you have asked for
and tom i cant see ps on on the psu

[tom66]

Re: Logik l32digb20

Readings look OK to me.
I haven't asked -- how often does the backlight flicker. Once a second, 2-3 times a second, 10 times a second...?
What about this pin?

[sordids999]

Re: Logik l32digb20

of that pin on the psu im getting 1.1 Volts,but with regards to the backlight flashing its every second but its intermittent one minute it flashes every second but sometimes just once then no backlight and sometimes the tv will go into standby all by itself

thanks

[tom66]

Re: Logik l32digb20

That 1.1V is steady? In the case where the backlight does switch off, do BLON or DIM change too?
If you adjust the BACKLIGHT in the user menu - if the option is available - what happens? Does flicker get better/worse?

[sordids999]

Re: Logik l32digb20

The 1.1 Volt yes is steady not sure which ones are BLON etc,and no tom i dont have the option to get into user menu basically the tv will load up with the logik logo then keeps flashing on and off,just now checked the voltage in the ps on and i had one backlight blink then nothing !