Pioneer KRP-500A Kuro plasma tv with KRP-M01 Media Receiver - Page 1
Forum section: electronics / repair

author: August
author_rank: Contributor
timestamp: December 09, 2014, 11:07:30 am
content: *Modified to show problem, probable cause and repair.This particular series of 9th generation Kuro plasma t'v's has a seperate media receiver which is connected to the panel by Displayport. The panel has to be connected to the media receiver to work. If there is a problem, the LED of the media receiver will blink.Problem: Set will not turn on or only sporadically, blue LED blinking eight times in a rowProbable cause: One of the voltage regulators is faulty (part is NJM2846DL3-18) These cost a couple of euro's or dollars, depending where you get it. I got mine in Germany fromhttp://etus-landgraf.com/index.php/component/virtuemart//pioneer/tv-plasma/krp-500a?oberkategorie=3&hilfskategorie=12&unterkategorie=2231Location: These voltage regulators are on the underside of the mainboard of the media receiver. There are several. Most likely culprit is ic 4606, but please measure during startup phase to be sure.Difficulty: Board level repair on a small part. Not quite SMD, but very easy to lift solder pads. Be sure to know what you're doing and have proper desoldering and soldering tools and skills.Otherwise, please leave the repair itself to a professional. The TV is worth it (best plasma ever made). Seperate media boxes are hard to come by and fetch quite a lot on Ebay.------------------------Original post:I picked up this set with a defect. Fault is as follows:When power is applied, the set will either stay in standby (red LED on) or give a fault. Most often, when cold the set will not give the fault and switch on. It can then be used for as long as I like with all possible sources. When I switch off and on again, it will show the fault and fail to switch on.I have the service manual for the panel and the media receiver including block diagrams and such.This fault is flashing of the blue LED on the Media Receiver eight times in a row. This is a shutdown mode, based on failure of the IIC communications. There are several faults possible.When pressing the info button on the remote during the shutdown, the fault is further designated by the orange LED. It flashes one time. This indicates a fault in communication with the DVB-T tuner frontend.For all IIC communications faults, the main IC that controls the periphial IC's on the pcb is a Pioneer/NEC unit. It is mounted as a BGA package.Anyone with experience with these units? As Pioneer has ceased plasma production years ago, spare media receivers are hard to come by and hideously expensive. I would be inclined to try a board/component level repair. Not having measured properly yet on the board, my current working hypotheses are:1. BGA solder failure on the main chip, rework/reball needed.2. Auxillary componentry such as onboard voltage regulator failure. Need to measure/probe signals with a scope or sniff out I2C communications.I don't think it's a fault in the panel as then the panel LED would blink to indicate a fault there. All indications show a fault in IIC communications line with the tv-tuner module. This fault does not occur in a cold situation.I can share the service manuals if anyone wants to take a look and chime in.

author: August
author_rank: Contributor
timestamp: December 15, 2014, 05:18:24 pm
content: From what I could find around the net (on a slovenian forum something about the kuro tv 5090h, which is from the same generation ) it seems that in this 9th generation pioneer plasma series the following voltage regulator can give rise to these kind of problems: NJM2846DL3-18. After finding this partnumber, I could find more indications on fora and even a reference to a youtube video.I disassembled the mediabox KRP-M01 and measured all those voltage regulators while powered and within the startup fase. Actually IC4606 is one of these 1.8V regulators which does not give any output when the fault occurs even when I do measure an incoming voltage. When the fault is not present this regulator does give the proper 1.8V out.I will order this regulator IC, replace it and let you guys know.

author: d3ron
author_rank: Newbie
timestamp: January 11, 2015, 05:15:36 pm
content: I've joined this forum, especially to fix this fault.So I also have the krp-500a and have started seeing exactly the same symptoms as yourself.I've watched the youtube video I presume you're referring toWere you able to fix it in the end?I have no electrical or soldering experience, but think I could carry out what is done in the video. Would you be able to post a picture of the krp-500 circuit board to show where NJM2846DL3-18 is?Regards

author: August
author_rank: Contributor
timestamp: February 11, 2015, 11:16:05 pm
content: I fixed it, it's working perfectly now.Warning, I do not recommend to do it yourself if you have little or no soldering experience. Especially you will need good desoldering equipment and skills. If you don't have that please just order the part and have a technician do the soldering for a little extra money. The part is quite small and it's easy to lift some of the soldering pads. These voltage regulators are on the underside of the mainboard so you have to take everything apart first. There is a service manual on the net.

author: d3ron
author_rank: Newbie
timestamp: February 12, 2015, 05:11:15 pm
content: Many thanks for the update...The reason I've never tried soldering is because I've never fancied using a soldering iron.However the hot air blower looks a lot safer. I reckon i should be able to gently heat it up using that and remove, add flux and replace.

author: d3ron
author_rank: Newbie
timestamp: February 20, 2015, 01:02:42 pm
content: Hi mate...I've got the NJM2846DL3-18 part and opened up the krp-m01 media box.Just a quick question...are the ic regulators on the bottom of the circuit board? I can't see them on the top, but would like to make sure before I fully disassemble.

author: tom66
author_rank: Super Contributor
timestamp: February 20, 2015, 02:28:49 pm
content: I've fixed two PDP-LX5090 with this same fault. One on my wall, one for a friend. Great TVs. (The PDP-LX5090 has the board with the 1V8 regulator inside the TV.)

author: d3ron
author_rank: Newbie
timestamp: February 20, 2015, 03:34:18 pm
content: That's good to know.I'm just trying to avoid pulling the media box apart completely until I know exactly where the ic regulators are.

author: August
author_rank: Contributor
timestamp: March 01, 2015, 09:36:50 pm
content: Quote from: August on February 11, 2015, 11:16:05 pmI'll just reconfirm they're on the underside of the mainboard. You have to take it apart completely.

author: d3ron
author_rank: Newbie
timestamp: March 01, 2015, 09:46:00 pm
content: Thanks for confirming.I'll contact an authorised repair center first and see how much they want and decide whether to go ahead.

author: vincentleung
author_rank: Newbie
timestamp: July 09, 2015, 10:26:18 am
content: Can anyone teach me how to open the krp-m01 receiver? The fan of mine doesn't work. I?want to replace it by myself. thanks.

author: vincentleung
author_rank: Newbie
timestamp: July 09, 2015, 10:37:26 am
content: Quote from: vincentleung on July 09, 2015, 10:26:18 am

author: August
author_rank: Contributor
timestamp: September 08, 2015, 10:50:20 am
content: Quote from: vincentleung on July 09, 2015, 10:37:26 amSorry, I don't visit these forums very often. Please google for the service manual: pioneer_krp-m01_wysixk5_wysxj5.pdf

author: borpet3339
author_rank: Newbie
timestamp: January 11, 2016, 04:59:37 pm
content: Hi there. I share the same problems as you mention with my Pioneer KRP-500AW (eight blinking leds). But when I follow your threads you are saying that IC4606 can be found on the down side of the main board on the receiver. When reading the service manual I can't find this part in the receiver so please help me out. Where do I find it?PS The YouTube you are refering to does not cover the KRP-500. DS

author: August
author_rank: Contributor
timestamp: January 27, 2016, 09:36:34 am
content: You need to completely get the mainboard out. There are three of these regulators. And I must warn, it is very easy to damage solder pads. I have now started to work with a hot-air station to do this. But still a lot of care is needed. Otherwise you can blow off other small components.My own Pioneer is working quite good, but not 100%. Most of the time it will take several tries on the remote to turn the tv on. It does not work from the power button on the media receiver at all. For me that's acceptable.Success is not guaranteed. There might be other components at fault. I tried to help someone else, but the problem remained even after replacing all three regulators.Please ask official Pioneer service to help if you can't fix it or are afraid to.

author: borpet3339
author_rank: Newbie
timestamp: February 29, 2016, 05:13:49 am
content: Thanks for your reply to my previuous question. I have found a man who were able to repair the box without changing the whole motherboard. He measured all the IC Circuits on the main board, found one faulty, changed it and then tried to stress the board up to 80 degrees without any problems. Got the box back and it now works perfect.

author: Philip J Fry
author_rank: Newbie
timestamp: July 28, 2016, 10:13:35 am
content: Hi everyone,I seem to have the same problem here, I'd just like to have some informations before starting the repair process.The first time the blu led blinked 8 times I disconnected the power cord from the media box, waited some time and reconnected. That seemed to fix the problem when it all started.Now it gotten worse: as soon as I connect the power cord to the media box, let's say 3 seconds after, the blu led starts blinking 8 times.So it doesn't allow me to even try to turn on the TV.Could anyone confirm the cause is the same as above and can be solved in the same way? Replacing voltage regulators?Thank you all

author: patrick93320
author_rank: Newbie
timestamp: July 31, 2016, 09:17:23 am
content: thanks to all people having shared the information.I got same issue ( blue led blinking 8 times at the start up) on my kuro KRP MR01 receiver.Problem was the IC4604 ( 1.8v regulator) . For the test, note that the 1.8V voltage appears only at the start up sequence. You can test it if you just open the bow by using the test point 4623 at the power up.The system was working only after several minutes in rthe fridge !!! so we can conclude to a component failure !I got some difficulty to change the CI so I soldered the new one using the existing CI and I just cut the output to solder the new CI output.Everything works now.

author: robash
author_rank: Newbie
timestamp: November 25, 2016, 11:22:58 pm
content: Hi, is there any chance of sharing the manual with me, im having the same issue, would really appreciate thisQuote from: August on December 09, 2014, 11:07:30 am

author: Bjoern
author_rank: Contributor
timestamp: July 01, 2019, 07:31:32 am
content: Hi there,can anybody here recommend how to check whether its the TV or the Media box that's at fault when the red and blue LED flashes and the TV doesn't switch ON ?When I disconnect the Media Box from the TV should both LED's blink once I press the start button ?I measured all the voltage regulators on the bottom of the Media Box board and they all seem OK.How could I insure that the issue is not caused by a faulty cable to the TV or the TV itself ?Cheers Bjoern