Sony KDL-46X3500 switches off and shows 5 red led diagnosis.

[jas123]

Hi, I have a sony kdl-46x3500 that presents with a 5 red led flash code.

It happened after it was moved, although I was told by the person who gave it to me that the tv had a power issue and wouldnt turn on, thats why he was throwing it out.

I took it off him and got it home and it worked straight away with out issue for a day. Then I moved it and got the fault.

The tv will turn on (green led) but no picture, then after about 30-1min will automatically switch off to show fault code.

I think the code means TCON problem, but I have unplugged the TCON and the connectors but the fault code stays the same.

After I removed the back and had been working on it (removed the tuner and the AVC board to access the FB2 board, I reinstalled the boards and the TV turned on to show normal picture. But when I turned it off and on again it went back to 5 led fault.

This has happened randomly twice, where it has come on, but then goes back to fault at restart?

I have tested some of the voltages but I need a more logical approach, as I dont know what order to test which voltage to where, to eliminate possible problems.

The caps on the pwer board look ok, and I cannot see any obvious problem....

I have the service manual and the schematics.

Im ok but no expert, I need someone with a bit of real experience to help if possible.

Thx.

[downunder]

I'm not terribly familiar with expected voltages on the T-con, but code 5 on Sony's invariably means a T-con error. Just once, I had the main board causing it. If the fault was induced by movement, I'd try using contact cleaner on all the flat flexi cables associated with the T-con and the display panel. If that fails, disconnect one of the flexies between the T-con and panel _ if panel ok, you'll get a pure white half screen. If this doesn't happen,refit that flexi and remove the other one. Again you'll get a white 1/2 screen if panel is ok. A black screen or a mass of lines in each case means the panel is faulty. You may have to remove the base &/or some hardware at the bottom to get at the flat ribbon cables.                 Bruce

[jas123]

Hey Bruce,

Thanks for the reply.

Bearing in mind what you have said. I have made some other progress which may change your advice.

First of all, I have unplugged the power to the TCON and the LVDS cable - restart gets same fault, so isolating the TCON does not change fault status.

If I unplug the LVDS cable from the FB2 Main AV board, and restart, the fault still remains.

If I unplug CN6150 from pwr board which directly feeds pwr to FB2 main AV board - and restart - the original fault disappears, and the green led start light stays on, but seems to cycle every 37 seconds - i.e. briefly go off, then on for another 37 secs) - but no 5 led self fault diagnosis shows?

I am wondering if this means the fault lies in the Main AV board FB2?

I have done other practical things also...

I have heated each individual board gently with a heatgun, allowing components to get pretty warm, and after each successive board, tried restart - no luck (Note I didn't heat actual left and right inverter boards.)

However....

As I was gathering and testing voltages at different points on different boards, continually recycling the power to get the readings, the TV display came on.... it stayed on for about a min and then turned off.

I noticed that the FB2 Main AV board was where the main IC heatsinks were heating up the most upon this recycling of power....the TCON IC heatsink warmed up also but not as much. So the FB2 board seemed to be the primary place heat began to pool.

I started to recycle the power, told myself I would do it 50 times as a test, that should replicate the effect of what I was doing as I was voltage testing previously when the TV came on.

On the 14th recycle, the TV came on again...

Stayed on for about 2 mins and then switched off.

When I tried to reapeat the process immediately afterwards it failed.

Bear in mind, that previously the TV/display had come on randomly in this way, once I replaced and reconnected the FB2 Main AV and TCON boards which I had removed...?

It was very random, but maybe the FB2 board has some micro solder joint damage, which was caused/exacerbated in moving the TV...me removing the board and replacing it may have briefly bridged the hypothetical crack allowing the board to function and TV to start...

Equally, as the FB2 Main AV board seems to react quickest to the heat, although its not conclusive, it does seem possible that recycling the power and raising the temp of components may create the same bridging effect to a micro fracture...

I a just trying to come up with theories, I could be completely wrong, and probably am.

I will try the power recycle test again from dead cold - see if the TV/display will come on again.

I have checked all the voltages on powerboard GF1 / primary inverter power board DF2 / Slave inverter power board DF3 / and FB2 which is I think classed as the Main AV board (LVDS from here to connects to TCON).

I will list the connectors by number and ref volt typed on circuit board and ACTUAL voltage, for reference.

The questionable things I noticed in my fairly ignorant diagnosis were...

On GF1 the Power Board...

The DIMMER voltage fluctuates steadily between 3.2v and 0v  ?

On DF2 the Primary Inverter Power Board....

INVRT DV 1L and 2L have 0 volts...where as INVRT DV 1H and 2H have 5v.   ??  (This reading also appears on the slave board CN6900 as they are directly connected.)

What I dont know, is where the circuit board has refs like BACKLIGHT, V-FB1, OCP2, FB etc which are all currently 0 volts - is whether this is correct. I am thinking that if the TV/display was actually on some of these other refs would get a reading.

But maybe I should have a reading at this stage anyway...that's my current level of ignorance..

I've checked around the boards and components generally to see if any readings seemed obviously suspect with my limited knowledge, and comparing with similar components elsewhere for similar readings and I have found nothing really. One 16v 10uf cap reads 9v where the two next exact same caps next to it read 4.3v. These caps are connected close to SCART input, so probably nothing.

One of the fairly large big red components on the AC side, There are about eight in total across the Main / Primary / Slave Power boards (regulating or smoothing?) next to the 4 large diodes which I believe cut part of the wave out of AC feed in. On of them on the Main Power board looks marginally damaged....but if you compare the AC readings all the others are 123v on one side and 121v approx on the other - and the damaged looking one reads 123v and 120v, which is less than 1% different so I don't think this is relevant. 

Having digested my progress, or lack of, I would appreciate any other practical ideas, or anyone with specific electrical expertise who could spot a missing voltage reading etc...or something out of line.

I wonder if there is any way to bypass certain areas of the whole system in order to test certain others individually, so as to remove them as potential problems.

I will try to upload some photos and I will put a video on YOUTUBE and paste a link here if I can. I cant connect my phone to my PC at the moment, so the photos are not as easy as they should be, but I will find a way shortly.

Bear in mind the TV worked under heavy use for a whole day when I rescued it, so theoretically it cant be that terminal hopefully?

Peruse the voltages below if it helps, and I will speak to you soon.

All the best.


GF1 - POWER BOARD CONNECTORS (TOTAL 5 - FROM NORTH TO SOUTH)

REF READING - ACTUAL READING

CN6151

REF - ACT

12 - 12.3
12 - 12.3
GD - 0
GD - 0
GD - 0
 6 -  6.2

CN6150

12 - 12.4
12 - 12.4
12 - 12.4
12 - 12.4
GD - 0
GD - 0
GD - 0
NC - 0
  6 - 6.14
  6 - 6.15
GD - 0
GD - 0
GD - 0

CN6152

12 - 12.38
12 - 12.38
GD - 0
GD - 0
AUDIO GD - 0
AUDIO GD - 0
AUDIO VCC - 13.6
AUDIO VCC - 13.6

CN6153

NC - 0
NC - 0
BALANCE ERR - 0
12 - 12.4
GD - 0
INVERT ERR - 0
BACKLIGHT - 0
DIMMER - 3.2V TO 0 VOLTS. (This reading rapidly fluctuates reliably between 3.2V and 0 volts?)
GD - 0

CN6154

BALANCE ERR - 0
INVERT ERR - 0
BACKLIGHT - 0
DIMMER - 3.2V TO 0 VOLTS (This reading rapidly fluctuates reliably between 3.2V and 0 volts?)
GD - 0
AC RLY - 4.82
PFC DETECT - 2.99
PS ERROR - 0
STNDBY - 4.9
GD - 0
GD - 0
NC - 0

 DF2 - PRIMARY INVERTER (LEFT) POWER BOARD (3 CONNECTORS TOTAL FROM NORTH TO SOUTH)

CN6706 -  (DIRECTLY IN FROM POWER BOARD CONNECTOR CN6153)

   - 0
   - 0
   - 0                                        ALL CN6706 MEASUREMENTS JUST REFLECT THAT THE CABLE FROM
   - 12.4                                    PWR BOARD CN6153 IS GOOD. THERE ARE NO REFERENCE MARKINGS
   - 0                                         BESIDE CN6706.
   - 0
   - 0
   - 3.2V TO 0V FLUCTUATING - (THIS IS DIMMER FEED FROM CN6153)
   - 0

     CN6701 - DIRECT OUT TO MIDDLE CONNECTOR OF LEFT INVERTER CN135

12 - 12.3
FB - 0
GD -0
NC - 12.3                    *
LD - 0   --  NO WIRE?  * THESE TWO MAY BE MISLABLLED?
LD - 12.3
LD - 12.3

CN6704 - FEEDS DIRECTLY TO SLAVE INVERTER (RIGHT) CN6900

CONN DET - 0
12 - 12.4
NC - 0
V FB1 - 0
GD - 0
INVRT DV 1H - 5V
GD - 0
INVRT DV 1L - 0 ?? - NOTICE ONLY INVERTER DV 1H AND 2H HAVE 5V READING? INVERTER DV 1L AND 2L = 0?
GD- 0
INVRT DV 2H - 5V
GD - 0
INVRT DV 2L - 0 ??
GD - 0
OCP 2 - 0

 DF3  SLAVE INVERTER POWER BOARD (RIGHT) CN6900 - FED DIRECTLY FROM CN6704 (PRIMY INV PWR BD)

OCP2 - 0
GD - 0
INVRT DV 2L - 0 ??
GD - 0
INVRT DV 2H - 5
GD - 0
INVRT DV 1L - 0 ??
GD - 0
INVRT DV 1H - 5
GD - 0
V FB1 - 0
NV - 0
12 - 12.38
CONN DET  - 0

ACTUAL INVERTER BOARD (LEFT)

CN 136

TP005 - LOOP2 - 0
          - LOOP2 - 0
TP006 - LOOP1 - 0
          - LOOP1 - 0
TP007 - PROTECT - 0
          - PROTECT - 0
TP008 - VCC - 12.3
          - VCC - 12.3
TP009 - GD - 0
          - GD - 0

CN135 ACTUAL INVERTER (LEFT) MIDDLE CONNECTOR. (CONTROL??).  FED FROM DF2 PRIM INV PWR CN6701

LD - 12.3
LD - 12.3
LD - 12.3
GD - 0
FB - 0
VCC - 12.32

ACTUAL INVERTER BOARD (RIGHT)

CN 235

TP055 - LOOP2 - 0
          - LOOP2 - 0
TP056 - LOOP1 - 0
          - LOOP1 - 0
TP057 - PROTECT - 0
          - PROTECT - 0
TP058 - VCC - 12.3
          - VCC - 12.3
TP059 - GD - 0
          - GD - 0
         

[downunder]

Wow! that's quite an essay. A couple of points.

If you disconnect power to, or the LVDS cable from, the T-con, the microprocessor on the main board still sees this as a fault.
When the TV is powered on, the micro does a wizz around and checks the functionality of the various boards. The absence of the T-con is akin to a defective T-con, and raises red flags for the micro, which then generates the error code.

If you disconnect CN6150, you're probably removing the 12V and 6V rails to the main. This possibly disables it, hence it is unable to detect faults. I think you said it sometimes does power on. If so, try and put it into the self-check mode. From standby, press Info > 5 > Vol+ > Power on the remote control. The resultant display will tell you which item caused the error.

If you have an electronic manual, why not upload it to "downloads" at the top of the forum page. I get the impression that this is an older LCD model that uses CCFLs to backlight the display panel - uses inverters instead of LED Drivers. Might give me a better idea of what I'm looking at.           Bruce

[promo7uk]

it does sound like a faulty led's 5 flashes on sony tv's is back light error.. if your dim is moving from 3.2 -> 0v id say backlight drain issue on psu., most sony tvs as downunder states here, will do checks and if it detects a fault gives the error codes. ive has alot of sony problems lately with the latest models. and most of them have been backlight issues what with the 5 flashes,, also had ,, colour test mode issues on some, turned out to be paired t-con. that sony like to be silly with software no wonder they fail alot.