Samsung ps50q97hd

[sordids999]

hello

just got this tv it seems the psu is clicking on powering up ive tried disconnecting the ysus/xsus but seems to be the same so im gathering its the psu ?

any help appreciated

[tom66]

Re: Samsung ps50q97hd

Check all the fuses on the PSU - a common fault on these is shorted FETs on the Vs or Va/15V tract; easily fixed.

[sordids999]

Re: Samsung ps50q97hd

it seems on further testing ive noticed on the underside of the psu some blown components

[tom66]

Re: Samsung ps50q97hd

Yep, looks like you have the common fault. It's not too hard to fix, and those component values are known from the schematic. I bet you will find adjacent transistors shorted.

[sordids999]

Re: Samsung ps50q97hd

yes tom as per picture there shorted alright

[tom66]

Re: Samsung ps50q97hd

Yep ! Pretty explosive failure there...

QX801,QX802 = FQFP11N50CF
DX803,DX804 = BAR43C (the "C" very important)
RX833,RX832,RX803,RX802 = 20R 1206
RX804,RX805 = 10k 1206
F803 = 250V 8A time-delay fuse

Power up initially with lightbulb in place of F803 = if bulb flashes install fuse and test TV.

[PowerAmpFreak]

Re: Samsung ps50q97hd

From pictures it's easily seen that reason for blowing is poor solderjoints on QX801 and 802.
Actually, I have only had one blowing up and numerous fixed only by doing new soldering.¨
Those PSU's are quite reliable.

[sordids999]

Re: Samsung ps50q97hd

http://www.ebay.co.uk/itm/CLICKING-1...item416e8f262a

would that work guys ?

and never really changed the small components before but i would say my soldering skills are pretty good so any good tips on changing these properly ?

[tom66]

Re: Samsung ps50q97hd

Looks good.
The small SMDs are easy enough - just flood each side with solder to lift off.
Look up SMD removal on youtube.

[sordids999]

Re: Samsung ps50q97hd

ok thanks hopefully update soon

[sordids999]

Re: Samsung ps50q97hd

Power up initially with lightbulb in place of F803 = if bulb flashes install fuse and test TV.

im guessing you mean incase something else blew the psu ? ive also checked fuses on ysus and xsus seems ok
but fingers crossed ive ordered the parts and ill update when i have recieved the parts
now time to test my skills on a old board before they arrive

[tom66]

Re: Samsung ps50q97hd

Mainly to avoid blowing up new parts - It is very rare for other parts of the TV to damage the PSU.

[PowerAmpFreak]

Re: Samsung ps50q97hd

As I said, failure is 99.9% because of bad soldering. This made the bridge crossconduct and blow.

[sordids999]

Re: Samsung ps50q97hd

hello i connected the parts but the test bulb comes on fine but switches of then comes on again with the relay clicking on the psu,ive tried disconnecting the ysus/xsus but its still the same ?

[tom66]

Re: Samsung ps50q97hd

That is normal for this PSU, all you care about for now is that it does not light up continuously meaning there are no shorts. You will have to put a fuse in and test it.

[sordids999]

Re: Samsung ps50q97hd

ok thanks its working VS is 205 VA is 62.5 but the tv wont turn on no picture sound etc

[sordids999]

Re: Samsung ps50q97hd

control board light is coming on and staying consistent but it seems the side button and samsung main power switch on the front is not working possible main board failure ?

[tom66]

Re: Samsung ps50q97hd

Is there a light glowing on the Y-main?

[sordids999]

Re: Samsung ps50q97hd

it seemed the ribbon going from the ysus to control board was removed and not put back properly from the previous guy who owned the tv all working at the moment but time for testing

thanks guys for your help

[sordids999]

Re: Samsung ps50q97hd

Does anyone know the length and size of the screws to mount the stand i never had any with the set