samsung ps59d6900 no vs or va after unplugging xsus

[daz2206]

hope someone can help with this as i have no idea where to start , the tv came to me working but restarted every 15 seconds (picture and sound were perfect) i assumed it was the mainboard but tried unplugging bits one at a time to see if it stayed on or not, when plugging the xsus back in (tv unplugged) i got a little spark at the connector and the picture didnt come back on after that, everything else seems fine but no picture, i bought a complete tv the same with a faulty psu and fitted the mainboard so tv stays on now but still no picture, on the ysus connector from psu i get.....
VS = 0.378V
VA = 0.01
B15V = 15.27V
i can add more pics if needed,
any help would be really appreciated

[Andrew F. Ali]

Re: samsung ps59d6900 no vs or va after unplugging xsus

Unwise decision to unplug the connectors while TV is powered. The Safer thing to do was remove power, then unplug connector, then re-apply power. You probably damaged the PSU, X-Main Bd. and the Main Bd.

[freakaftr8]

Re: samsung ps59d6900 no vs or va after unplugging xsus

The spark you received on the x connector is usually because the power supply has stored voltages in the capacitors I usually wait about 10 to 15 minutes after powering a supply down to reconnect either power connector to the sustain boards. You might wanna check and make sure that you didn't arc over the contact on the pin and now it's not making a firm connection. Also make sure that you didn't blow in a fuses from the spark.

Agreed. Hopefully you were not trying to connect and disconnect power connectors with the power on not only is it's dangerous but deadly to a power supply and sustain boards

[R_J]

Re: samsung ps59d6900 no vs or va after unplugging xsus

Remove the power supply board and check the solder connections on the transformers.

If you get lucky, the arc may have just shut the power supply down, But you may have either damaged something on the power supply board or the Ysus board, check the resistance across the pins Vs and Ground WITH POWER OFF

[freakaftr8]

Re: samsung ps59d6900 no vs or va after unplugging xsus

Remove the power supply board and check the solder connections on the transformers.

Right that was my next comment I forgot to add. Also check the soldering underneath the mosfets and diodes that are attached to the aluminum rails. it would not hurt to re solder them anyways along with the transformer contacts

[daz2206]

Re: samsung ps59d6900 no vs or va after unplugging xsus

thank you all for your replies, i did have the tv powered off while disconnecting/connecting things but even after reading toms plasma troubleshooting guide i kind of skipped the wait 15 mins bit :-( and only waited a couple of minutes (which felt like 15 mins when stood waiting) il check the power supply when i get home tonight and try resoldering, i have all the boards from the donor tv so i can use the ysus and xsus from that if needed, as far as im aware it was only the power supply blown on the donor tv, i did try plugging the donor tv psu in and it blew the thermister, mains plug fuse and tripped the house electrics. (it wasnt connected to any other boards when i plugged it in) hopefully if its just one or 2 components damaged on my psu i can salvage them from this donor psu. thank you again for your help

[daz2206]

Re: samsung ps59d6900 no vs or va after unplugging xsus

After wasting an hour or so messing with it i gave up and bought another power supply but unfortunately it was still the same (no vs/va) so i swapped the ysus from the donor one and it all works fine apart from a buzzing noise from ysus board. My question now is should i leave it alone now its working or can i try my original psu back in to check its still ok or do i risk more damage by trying it with a good ysus ?

[Andrew F. Ali]

Re: samsung ps59d6900 no vs or va after unplugging xsus

I think you could retry your original PSU now that everything works. This way you would know for sure if you have a working PSU or not. As far as the buzzing in the Y-sus Bd., look for loose soldering on the heatsinks and on the board in general and tighten the screws on the HV Upper and Lower scan/buffer Bds. attached to the Y-sus Bd.

[daz2206]

Re: samsung ps59d6900 no vs or va after unplugging xsus

Thank you. Il try now. No i wont !! Il turn it off and wait 30 mins then try :-)

[R_J]

Re: samsung ps59d6900 no vs or va after unplugging xsus

Check the voltage on that Vs plug after you unplug the tv and make sure the voltage has droped down to a couple volts. then you will be ok.

[daz2206]

Re: samsung ps59d6900 no vs or va after unplugging xsus

original psu was still fine (just the original ysus was damaged from plugging it back in too soon), i couldnt fix the noisy ysus so just bought one off ebay so finally all up and running fine, thank you all for your help and a lesson learned for me.