Sony Bravia KDL-46VE5 Repair Help/Service Manual Power-On Click - Page 1
Forum section: electronics / repair

author: edy
author_rank: Super Contributor
timestamp: December 31, 2017, 05:09:10 pm
content: Hi Folks,I picked up a curb-side Sony Bravia KDL-46VE5 LCD TV, circa 2010. No obvious screen damage. Checked continuity across the mains plug, there was some resistance initially that dropped with time. Popped open the hood, took the attached pictures, checked the fuse which was fine. Unplugged the logic board plugs (top right corner) ribbon cables from power board to see if would get backlight on... no luck.The TV makes a CLICKING sound when the power button is pressed, then after a while the click happens again, then it starts to click again... Sounds like a relay trying to get it started. I've had this issue with a Samsung which I successfully fixed by replacing some bad caps... The Sony doesn't have any obvious physically-bulged or leaking capacitors that I can see. Where do I go from here? Should I just remove all caps and use my ESR tester to check every one? How do I more quickly isolate the problem? I don't have a service manual... any help would be appreciated.Consumer manual:http://static.highspeedbackbone.net/pdf/S190-5242.pdfPower supply found here:http://www.shopjimmy.com/sony-8-597-105-10-power-supply.htm(no parts kits listed, otherwise that would be a good place to start checking those components first)There is a physical flip-switch that is supposed to completely turn off the TV power (completely isolate from mains), or turn it on to supply "soft-power" to the TV to be in standby mode. I was reading some forums that discuss pressing soft power and home buttons at the same time for a few seconds, that might reset some software. However, I see no LED light anywhere, no status light whatsoever. I need to look and see if those are on, I didn't look carefully enough. However I would expect at least the status light to be on once the physical switch is turned on to indicate standby. There were a bunch of suggestions here:http://community.sony.com/t5/Television-General/Sony-Bravia-wont-turn-on/td-p/444692Knowing the age of the TV and the clicking, I suspect capacitor issues... also many of the comments seem to indicate that the TV does eventually power up but it takes a while, and that once it powers up it seems to stay on. This is similar to the classic Samsung clicking on power up issue, which capacitor replacement fixed. I will keep searching for a service manual and parts list but if anyone can give me some advice in the meantime I would be grateful.

author: edy
author_rank: Super Contributor
timestamp: December 31, 2017, 05:34:30 pm
content: I found service manual online here but can't download it... can view one page at a time for now, will see if there is free subscription option for this site to download the whole PDF:https://servicemanuals.us/sony/tv/kdl-40ve5-kdl-46ve5-kdl-52ve5.htmlI propped up the TV so I could see the front panel and buttons more clearly. The STANDBY light does come ON... When I press POWER, the green light comes ON! Then after 5-10 seconds it turns off and then the STANDBY RED light comes on again and blinks 6 times, then stays off, then blinks again 6 times, etc.... I can press POWER button again... does same thing, turns power light to GREEN... again 5-10 seconds with no image (no menu display, no input indicator, nothing but blank screen) and then off again to the RED STANDBY light which blinks 6 times, repeatedly.According to the service manual page 6 it indicates a backlight issue:https://servicemanuals.us/sony/tv/kdl-40ve5-kdl-46ve5-kdl-52ve5.html?start=11I also found this guide, worth a shot:Quote

author: edy
author_rank: Super Contributor
timestamp: December 31, 2017, 06:42:49 pm
content: Ok.... some progress!!!!I unplugged one of the ribbon cables going from the main power board to the left side of the TV... in order to check power coming off the board. That port indicates a number of 12V outputs and GND which I did not get any voltage on when checking with multimeter. However, just by unplugging that connector the TV powered on! Backlight on, menu system working, seemingly everything works?Now I need to delve deeper into what exactly that ribbon cable feeds and whether the correct voltages are being sent across. Interesting....I REPEAT.... WITH THE CABLE UNPLUGGED (as indicated in picture SONY7.JPG below) THE TV POWERS ON AND LETS ME BROWSE MENUS, ETC... I DID NOT CHECK SOUND (could be a sound amp issue... perhaps that power supply is feeding the speaker system is causing a fault). As soon as I reconnect that cable, the TV goes back to having that same issue!It is a 9-pin cable with pins as follows and labelled as "107 1-910-057-81 CONN ASSY, 9P MM CRIMP (KDL-46VE5 ONLY)" in the service manual:HEATER-ONFBGNDGNDGNDProtectVCC-12VVCC-12VVCC-12VIt says on the schematic then it goes TO BALANCER BOARD.

author: edy
author_rank: Super Contributor
timestamp: December 31, 2017, 08:40:06 pm
content: Ok, I'm a bit perplexed at this point....I plugged in a Roku stick and was able to play Star Wars from Netflix with beautiful sound and graphics (see images below), no issues whatsoever. The "input" detection was a bit wonky but it did manage to see the Roku and displayed things once I pressed some menu buttons. I also activated the input detection on all inputs just in case, I turned off all the "eco" settings and such. I'm still not sure what the heck is going on.What in the world is that cable supposed to be doing? Cable 107 (9-pin going from the POWER SUPPLY to BALANCER BOARD isSTILL UNPLUGGEDyet the TV is working. Schematic shows it to be cable going from MAIN POWER to INVERTER BOARD (INV)? Although other manuals call is a "balancer board". I have no remote and cannot go into the diagnostic modes, unless I can use my Universal remote (not sure if it is compatible or has all the appropriate buttons programmed to match Sony's original remote).The cable runs from the port on the lower right side of this schematic:https://servicemanuals.us/sony/tv/kdl-40ve5-kdl-46ve5-kdl-52ve5.html?limit=1&start=44...To the inverter board.... which unfortunately is listed as being part of another Service Manual on this page:https://servicemanuals.us/sony/tv/kdl-40ve5-kdl-46ve5-kdl-52ve5.html?limit=1&start=50The inverter board is labelled 212 and it says to REFER TO THE LCD PANELS SERVICE MANUAL.Is it part of the eco save mode? Is it supposed to balance out the backlight? Is that circuit erroneously telling the TV to power down? I'm still going through schematics to figure out what that part of the circuit is involved with, but if it works as is without causing any damage I would just leave that cable unplugged and away we go.Any ideas?I found a service manual that talks more about the "Balancing Board" here but it is for another model of TV:http://diagramas.diagramasde.com/otros/Sony%20Service%20Manual%20KDL-40Z4100_B.pdf

author: edy
author_rank: Super Contributor
timestamp: January 01, 2018, 11:08:43 pm
content: I've run the TV with a variety of sources, set up a universal remote, so far it is working fine AS LONG AS the cable I showed above is UNPLUGGED from the power supply. I have not found any more information on the purpose of the cable. Both inverter boards seem to work fine, the image is bright and clear across from entire screen so I assume that cable powers some logic involved in diagnostics or balancing brightness in case of change in lamp characteristics over time?Any ideas yet from anyone why the TV works and what it's for?

author: Bud
author_rank: Super Contributor
timestamp: January 02, 2018, 07:42:07 am
content: Did you say there was no 12V on the connector on the power supply side? I think you should check why. The cable may supply power to a circuit on the inverter board , which controls the Protect line. And abscence of the signal on the Protect line shuts the power supply off.

author: edy
author_rank: Super Contributor
timestamp: January 02, 2018, 04:31:02 pm
content: Thanks for the suggestion. That's what is perplexing... Absence of the signal actually allows the TV to turn on and function normally. Whatever is going on, it must use a "0 V" as the signal to allow it to power up, or there is a comparison between 2 ZERO-voltage signals and it uses a "0" difference as being "ok" status, except that in this case BOTH are 0V instead of 12V. As long as the cable is unplugged, it works.If I plug the 9-pin cable to the power supply (while the TV is in operation) then it immediately shuts it off. With this cable connected as it should be, the TV powers on and then shuts off a few seconds later with 6 STANDBY LED flashes indicating some fault (in either the Inverter board, power supply or some other thing). When I disconnect that cable, it works.

author: Bud
author_rank: Super Contributor
timestamp: January 02, 2018, 08:39:02 pm
content: This is what you said:QuoteSo I was asking did you trace why you do not have VCC-12V on that connector? This line seems to be supplied via L6604, so maybe that inductor is bad ?You can find the service manual with schematic onthis forum(need to register).

author: Bud
author_rank: Super Contributor
timestamp: January 02, 2018, 08:46:11 pm
content: If to assume the level on Protect line is active High in normal operation, which means Q6714 is off, then disconnecting that connector will not change the off state of Q6714. If you have a fault in the Balancer module and the Protect line is Low, it pulls the base of Q6714 to ground causing it to turn On and indicate a fault to the MCU. In this case disconnecting the cable will return Q6714 to Off state removing the fault condition from the CPU pin. Possibly this is what you are observing.

author: edy
author_rank: Super Contributor
timestamp: January 03, 2018, 07:58:42 am
content: Thanks for the suggestions and schematic, and suggesting the Russian forum... I registered and downloaded schematics/service manual from this thread, it is a few posts down as they list a number of Sony models:http://televid-sib.ru/index.php?topic=22332.msg62615#msg62615I see the inductor L6604 which is connected to the three 12V pins and the Q6714 is connected to PROTECT. It looks to be quite a complex system, which is beyond my experience level. The problem may be on IP3N power board, but I do not trust having tested the pins properly with my multimeter... if so, then I would be able to check across L6604 for continuity if I don't see 12V on the pins... if that failed then that may be causing no 12V on the cable pins, which then causes the fault perhaps to signal back from the balancing/inverter board to the power supply as it is complaining it is not getting 12V to some circuit? Maybe then with the cable not attached it doesn't allow signal to pass back to the power board (presumably through the PROTECT pin?)... which is strange if it was designed this way as it would mean LOW signal on PROTECT meant all ok (not HIGH). I still can't understand how disconnecting a 9-pin ribbon cable would not cause major issues with the set ... unless it is used only for self-diagnostic sensing and not supplying any otherwise critical circuits for TV functions. It could be the self-diagnostic circuits are faulty and removal of that cable somehow bypasses them (which may be how the TV was designed)?If the issue is on the balancing/inverter board then it will be a more difficult job to fix. There are many SMD's on there and some chips, apparently it is one piece part with the entire display including all the CCFL's. I cannot find any schematics on the balance/inverter board and apparently if that goes then you have to change the entire panel which is why they don't bother putting it in the service manual even (it has it's own separate service manual). The TV service manual only lists BM3 (main video/audio logic board), HLR4 (LED indicator board), HSR (optical "presence" sensor board) and IP3N (power supply). Assuming one of the CCFL's has gone, it is not noticeable. I cannot see any deficiency in the display at all. The backlight settings seem to work, I can change the brightness up and down and also notice the difference in VIVID/STANDARD/CINEMA/CUSTOM modes. The display is bright and well illuminated across the entire image from edge to edge (as seen in previous photos posted).So for the time being I am going to leave it alone, but I am still bothered by not solving the problem and wish I could devote more time to figure it out. I am also anxious about damaging the TV further by poking around. Whatever is going on, it is not affecting the set from operating normally, and whatever that cable is doing seems to also be non-critical. I've been running the TV for hours on end for the past couple days watching Netflix off a Roku stick and there is absolutely nothing I can see wrong.I have another 46" Samsung in the basement (also grabbed from a curb on garbage day) which will entertain me further. I'll devote my time to fixing that one and meanwhile keep you posted on how this Sony 46" does.Thank you everyone for your help!!!

author: Bud
author_rank: Super Contributor
timestamp: January 03, 2018, 03:32:00 pm
content: Quote from: edy on January 03, 2018, 07:58:42 amYes your thought flow is correct. But I am not sure why is it so difficult to measure and confirm +12V on that connector on IP3N board. That would give you more clues, you should do that as the next step.

author: edy
author_rank: Super Contributor
timestamp: January 03, 2018, 03:48:27 pm
content: Yes thank you, I agree. I don't want to defeat protection on the TV if it may cause a fire hazard due to some overloaded overheating component on the power supply. Now that I have the schematics I can look more carefully at the power board. If I am not getting 12V off that 9-pin connector on IP3N then hopefully that isolates the main problem to the power board (and my LCD panel/balancing/inverter boards are hopefully fine).Is it ok to simply check the 12V pins against those GND pins on the same 9-pin connector, or should I clip somewhere on to a main GND somewhere else? I can check continuity of those GND pins to a more main GND rail somewhere while power off to make sure they are all at the same level relative to each other, to confirm that the connector GND is indeed ground... otherwise if I am seeing 0V difference at the connector between GND-12V it could also mean that my GND is at 12V or floating? And I should be able to confirm that I am getting 12V higher upstream (before the inductor) relative to GND and see where in the circuit I lose my 12V indicating the failed component?

author: edy
author_rank: Super Contributor
timestamp: January 03, 2018, 09:10:45 pm
content: OK, I pulled the TV off the wall. I don't want it to cause any fires until I figure out what is happening and fix it. I checked the pins on the 9-pin connector at the power supply, and voltage do check out ok (HEATER ON, FB, GND, GND, GND, PROTECT, 12V, 12V, 12V). Voltages on the 12 V pins was hovering around 11.9 V or so compared to all the GND pins. When I plugged in the cable and checked the voltages again, all were still ok and PROTECT was at 12V while it was flashing green LED (power up diagnostics) until it auto shuts off and flashes red 6 times... at which point everything drops to 0V since it turns off.I've attached some photos of the balancing/inverter board. There must be some diagnostic circuits there at the corner as you can see it passes that 9-pin connector to CN8001 at the side of the board and then runs down with almost all the pins through to CN8002 which then continues on another 7-pin connector over to the other side of the TV (the other inverter board) presumably to check some stuff over there for errors as well. Notice all these "000" jumper SMD resistors/links to jump traces across the board without having to use another layer.Any suggestions as to what to check from this point on? I do not have schematics for the inverter board for this TV so I am not sure where to go from here. I could start by checking all the jumper links and resistors... first check continuity of all jumper resistors to make sure all of them are 000, and perhaps some of the other ones to see if the values match what is written on them? I can try and trace the PROTECT line and see where it goes to.I can also try to short PROTECT to a 12V line or down to GND and see what it does by forcing the signal to either HIGH or LOW... but I don't want to fry any components in the process. I can also try to dig up the other side inverter board and see whats on there but it will take more work taking apart stuff because it is hidden behind more boards as the last photo indicates.Thanks for any suggestions.

author: coromonadalix
author_rank: Super Contributor
timestamp: January 05, 2018, 12:29:48 am
content: the tl494 is an pwm osc controller you can find datasheets for it may help a littleon this site : you have your inverter board for 12$ :http://www.shopjimmy.com/sony-a-1602-920-a-zl-board.htm-- i would buy it immediately at this price, maybe 2 boards.ebay :https://www.ebay.com/itm/Sony-A-1602-920-A-1-878-645-13-173046713-ZL-Board-For-L42HDTV10A-/252328649865You could remove the board and check around the metallic aluminum capacitors for low impedance between the capacitors pins and ground,Maybe its my eyes, but between the cn8001 and the ic tl494 the board seems to have heated a little, ''brownish''' looksJust checks for cold joints, i would redo all the solders there with a fine tip and flux ... could you host the schematics on a file hosting service and pm me the link, i could help you ... i'm a technician i've worked on sony plasma and lcd tv's ... im checking for a service manual

author: coromonadalix
author_rank: Super Contributor
timestamp: January 05, 2018, 12:50:10 am
content: this inverter board is not shown in the service manual it seem ??Normally the main psu would need recapping even if the capacitors are physically fine, and check for bad solders, this board heat a lot ...My hint would be to check the two smt transistors near the 2 pwm black transformers, may became leakyBetween the 12v and ground on the pcb once cn8001 is disconnected what impedance do you have ?

author: edy
author_rank: Super Contributor
timestamp: January 05, 2018, 07:16:29 pm
content: Thanks for the help. I've done some more testing for Voltage on the pins of then CN8001 and CN8002 connectors when the TV is turned on and here are the results:Testing the pins at CN8001 with the 9-pin cable still plugged normally (from LEFT inverter to PS board), I am getting ~11.9V on all 3 of the 12V lines when compared to the GND. However, the PROTECT pin is showing 0V. Remember, when the 9-pin cable is not plugged in I measure about 12V on the PROTECT pin on the power-supply side. Somehow it is being pulled down to 0V when the 9-pin cable is being used... Perhaps that is how it is signalling the PS board to shut down. By default the PROTECT pin seems to be set at 12V on the PS board... and it is being pulled down to GND by the inverter board when there is a fault? When I don't have the cable connected, the PROTECT pin doesn't get pulled down and stays at 12V leaving the TV to stay on?Continuing with voltage testing now at CN8002 (which is 7-pin cable going to the other inverter on the RIGHT), with all cables still plugged in normally, now I am getting also around 11.5V on the two 12V lines (a bit lower than what I was seeing at CN8001) when compared to the GND pins at that connector. There is also a PROTECT-2 pin, which I am getting 10.5V signal on.... maybe that means the RIGHT inverter is ok. Perhaps if the right inverter was a problem it would also show 0V on PROTECT-2 pin at the CN8002 connector. Meanwhile the PROTECT at CN8001 is still showing 0V.

author: coromonadalix
author_rank: Super Contributor
timestamp: January 05, 2018, 07:56:48 pm
content: pm sentWhen the tv stay on with the removed cable of the inverter board, did you check all the main psu voltages ... normally when capacitor are leaking you will have some ac voltage on top of the dc voltages, sure its an high frequency, it may go up to 100-200khz pwm frequency ...Just to be sure that the main psu is ok as a good start, normally i recap the psu automatically with good capacitor brand at 105 degree temp, this model is not recent loll0.5 volts drift are sometime acceptable, depends of the circuit tolerances and structure.As i said, check voltages impedance when tv is off on the cn800x connectors, when plugged and unplugged ... and i did not see any inverter schematics, it will be hard to help without having it on my benchThe inverter board is essentially an pwm power supply, may outputting up to +/- 600v for cfl lamps, sometime variable because of the contrast / brightness settings, but seems fixed in this tv.The tl494 may send protection signal because of over current, bad solders, bad capacitors, bad contacts etc ... the two power mosfets near the black transformers may have heated a lot and degraded over time, seen lot of that in lcd monitors, they use the pcb has heat transfert.

author: edy
author_rank: Super Contributor
timestamp: January 05, 2018, 08:14:39 pm
content: Thanks I will start looking at those things you suggested. By the way I confirmed if PROTECT pin is shorted to 12V on inverter board at CN8001 it will keep TV on even when cable still connected. So that must be signal of fault, circuit on inverter pulls PROTECT pin to 0. If you short it to 12V or unplug cable, power supply sees 12V remain on PROTECT pin and keeps things on after diagnostics bootup.

author: Bud
author_rank: Super Contributor
timestamp: January 05, 2018, 08:20:14 pm
content: In abscence of the LCD inverter schematic you should not place a dead short to 12V on the Protect pin with the cable connected, you can permanently damage the LCD board.

author: edy
author_rank: Super Contributor
timestamp: January 05, 2018, 08:32:51 pm
content: Note taken... I realize it's a stupid idea, I can fry something on the protect circuit as I have no way to know without a schematic what is further upstream and what kind of current can result through those other components.I tried to remove the inverter board but can't figure out how to safely pull it away from the white tabs at the side holding it in. I assume those white things secure in the ends of the CCFL's. Do I need to apply more pressure or pry something in each one to loosen up the board?

author: coromonadalix
author_rank: Super Contributor
timestamp: January 05, 2018, 08:41:17 pm
content: it will be removed when you lift one side and slide it opposed to the cfl sockets if i'm relying to the ebay photos?Just buy a spare part, it will be easier to service ... at 12$ usd minus shipping its not expensive i tell you, if you have basic electronic skills, don't loose to much time, you may do some damages on the tvI had an commercial grade sony plasma tv in the past, bought 25$, costed me around 75$ for the inverter, this tv had an really huge backlight, not cfl based.But WOW once repaired, terrific image quality .... my only plasma tv in my life, resold it for 150$ after 2 year of use, it weighted a ton, could not put it on a wall loll

author: Bud
author_rank: Super Contributor
timestamp: January 05, 2018, 11:01:23 pm
content: I'd agree on buying a replacement LCD board, it seems to can be found cheap. Even if it won't work it is a small loss.

author: coromonadalix
author_rank: Super Contributor
timestamp: January 07, 2018, 04:48:25 pm
content: hum under your BU board (the rca inputs ....) could you dismantle the long black cover of the board under it, if its not a second inverter i dont know what it is ?? but it receives the cn8002 plug seen on your photosThe sony service manual show mostly the 40" model, the cabling is incomplete and i have hard time to see where cn8002 goes ...page 72 and p73 show some inverter schematic, but they don't fit your 46 "model who as an tl494 ic controllerthe secret here is your chassis number ...

author: coromonadalix
author_rank: Super Contributor
timestamp: January 07, 2018, 05:06:29 pm
content: Not even sure i would order a new inverter board, try to find an Sony service center, sometimes they could accept to print and or sell you service manual copiesyour lcd controller interface is on the top under the shielded aluminum casing, not related to the cn8002 connector ...It is not complete for your 46 to 52 " model ... Sorry don't know what to say more

author: Bud
author_rank: Super Contributor
timestamp: January 07, 2018, 05:44:22 pm
content: What IC8000 is marked?

author: coromonadalix
author_rank: Super Contributor
timestamp: January 07, 2018, 06:19:46 pm
content: ic8000 should be an lm339 or any equivalent number, the photo flash is negating the ic markings ... i cant see