Sony KDE-50XS955 11 flashes

[freakaftr8]

Hello all,
Long time, been busy with the kiddos lately,

Well I picked up this set from a friend that said it just died when he went to turn it on. Alot of people seem to have this particular issue in this model Sony plasma. Panel is made by Pioneer. All other boards in the set are propreitary sony. Anyway, as it turns out all voltages are there upon startup except VD and VS. All I found on the internet is board replacement and the Power supply is vague on any schematics.

So as I have it now, after much troubleshooting the SMPS, turns out that if I monitor the VS output with a DVM which hovers around 1.5vdc on startup and I heat up the very bottom area around the opto isolator, and I can only assume this IC is AC DETect, the voltage increses sligtly to 3v and then I get full 195vdc and the tv comes up perfect.

So I replaced the opto, no avail. What can cause this issue? Im thinking on the lines of caps around the opto, or possibly the shunt regulator? Has anyone had this issue before?

Thanks


Thanks

Edit: It appears that the area may not be isolated to around that optoisolator but the other opto's as well. Replaced those too, no change. I get so startup voltages in vs and VD unless I either heat the areas, or short pin 3 and 4 momentarly of the opto's. Heat made dono difference this that that area

[freakaftr8]

Re: Sony KDE-50XS955 11 flashes

Ok it seems to be directly related to the shunt regulator off the optoisolator on the bottom of the power supply if I heated up the set powers up if I cool it down the set goes into fail mode. Has anyone ever seen a temperature-sensitive regulator IC

[tom66]

Re: Sony KDE-50XS955 11 flashes

I have, several times. Looks like you've found the problem...

[freakaftr8]

Re: Sony KDE-50XS955 11 flashes

Its a to-92 package. Part Number 1431a. I dont quite have this transistor. I do however have az431a the cathode and anode in reference are backwards but the characteristics seems similar

[tom66]

Re: Sony KDE-50XS955 11 flashes

TL431 is the same part, just be sure to match pin out. AZ431 should work too, if you can swap the pins.

[freakaftr8]

Re: Sony KDE-50XS955 11 flashes

Hmm not the problem. Replaced the regulator and still the same.

[freakaftr8]

Re: Sony KDE-50XS955 11 flashes

Found it ic6701 is a sony proprietary cxd9841m ic that seems like it feeds vs abd vd circuits. When I heat it up its on. When cold its dead.

[tom66]

Re: Sony KDE-50XS955 11 flashes

Well, at least you can buy it
http://www.ebay.com/itm/1-Piece-New-...-/190801890580

[freakaftr8]

Re: Sony KDE-50XS955 11 flashes

On a side note I have never seen a plasma where the y and z sustain boards are combined into one board! Very interesting pioneer design for sony so sony can implement all there other crap into it. The power supply takes up the area for the y board and the y/z combo is on the right side.

[tom66]

Re: Sony KDE-50XS955 11 flashes

It's actually an NEC plasma. NEC used to make plasma panels, actually they were one of the companies to make it commercially viable. One of the first panels after Pioneer bought them out but it's exclusively NEC with the odd Pioneer logo on the panel and PCB. There are a few components on the common driver (Z sus) but yeah, all the main power electronics in one large IPM under the massive heatsink.

I've never understood why NEC put the scan driver (Y-sus) on the right hand side, but after Pioneer put out their new panel, they switched it to the "conventional" left hand side... very odd.

I fixed one of these up for my dad (well it had an NEC badge but was otherwise the same.) Awesome TV. Aside from the black level not being as low as I'd hoped, it looked better than any LED TV I have ever seen, and it was 7 years old!

[freakaftr8]

Re: Sony KDE-50XS955 11 flashes

That explains it. I repaired a marantz with an nec panel and guts and was identical to an nec. I didnt know pioneer bought nec pdp business. Thought it was fujitsu. Learn something new every day. Lol. Now im worried about the cof ribbons. Lol nec is known for that defect.

[freakaftr8]

Re: Sony KDE-50XS955 11 flashes

Hey guys. Just got done replacing that ic6701 on the power supply. I may have shorted something because I briefly had a pic then alot of mal discharge and then I unpluggedit right away. And then I checked my connections and found nothing wrong. no when turned on im getting 6 blinks red. I don't know what this code means but I can tell you that I have no vs or VD voltage is at all no fans no nothing I did find a burned out ceramic resistor 3ohm 10watt on the vd tract output. I replaced it and did some general testing on the board it did not find any problems. So now I'm trying to figure out in backtrack what I did wrong. So does anybody know what six blinks is all about?

by the way all my primary voltages coming off of the sub power supply board for the 380v supply input are.there.

[freakaftr8]

Re: Sony KDE-50XS955 11 flashes



r6801 is what went bad afrer ic6701 replaced

[freakaftr8]

Re: Sony KDE-50XS955 11 flashes



ic6701 is what I replaced

[freakaftr8]

Re: Sony KDE-50XS955 11 flashes



the whole board

[freakaftr8]

Re: Sony KDE-50XS955 11 flashes

If anyone is familiar with this chassis please let me know. I found 6 blinks means low B+

[tom66]

Re: Sony KDE-50XS955 11 flashes

B+ typically means the voltage across the large 450V caps.

[freakaftr8]

Re: Sony KDE-50XS955 11 flashes

Would that be something loading down? Its internal to the power supply. I cant seem to tell what I managed to do.

Oh well. Maybe ill go tinker with my 1973 RCA CTC-42. Shes good to me. Lol

[Truncatedhose]

Re: Sony KDE-50XS955 11 flashes

Hey Freak, did you ever revive your KDE-50SX955? I just got one with the 11 blink code.

[Truncatedhose]

Re: Sony KDE-50XS955 11 flashes

Bump