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Hi,

A couple of years ago, I posted a repair procedure for Benq W5000/W20000 with half image artifacts. The cause was a design flaw on one of the onboard DC-DC converter, feeding power to RAMBUS framebuffer memory.



Now, I wanted to share with you some repair solutions that you can try for yourself if you have some soldering/desoldering skills/tools or you can go to an electronic repair shop and ask them to change the parts for you.

The fixes will apply to many JVC models (DLA-X3, X7, X9, RS40/50/60 etc), the ones that use Rubycon RPB-0526GA or QAL1305-001 in JVC part numbering.

A bit of background story.

After my first experience with JVC LCOS projector, all I can say is that I've converted from 1 chip DLP to 3 chip LCOS. So, I've traded excellent inherent DLP sharpness with fantastic native contrast and black levels of JVC optical engine.



I've bought mine (DLA-X9) with a faulty ballast, in excellent condition otherwise. At that time, I knew the fault was on the ballast board after trying with a new lamp and measuring signals from mainboard to ballast unit. The mainboard attempted a few times to turn on the lamp then the projector entered in error state with LED condition indicating a failure to start the lamp. Back then, I was lucky to find one used for about $100. I bought it as I was anxious to see the projector working, not having seen one in action before. The joy lasted for about 700h and then again, same symptom. Good lamp would not ignite...another failed ballast. I started to look at my old ballast board to see if I find something wrong with a basic DMM, not having it powered. I found none. I've dismantled again the projector, took the second ballast and looked at the board. Here, there was a fault that I saw without even using the DMM. A resistor close to the power input connector appeared shot. I measured it and it was open. Now, the resistor would not fail on it's own so the culprit was a SMPS controller chip, LNK364 which was feed through this resistor directly from the main 400V. This chip is used as a DC step down from approx 385V to about 17V for other low power circuit stages and finally stepped down to 5v (through a 3 pin LDO) for MCU on logic daughterboard. LNK363DN was shorted so that's why the resistor failed. I replaced LNK chip, LDO chip, resistor. Measured once more the other parts of the circuit for shorts. All appeared good. With hope that the logic daughterboard survived this, I put the projector back together and tested it. BINGO, it worked. I was happy that I was able to cure this just with a couple of $ not having to buy a ballast again. I started to think again at my old ballast...resistor and LNK chip were fine on this one. But as I didn't had time to further investigated I let it away. It didn't take more than a month and again, the projector didn't want to ignite the lamp. I tried to imagine myself dismantling again the projector to get to ballast board. It's not such an easy task. There are a lot of cables, connectors, screws, plates etc. I did it again. This time, resistor fine, LNK chip fine, LDO fine so the logic board received power, like on my old ballast. So I had 2 ballast boards, not working, with apparently the same fault. I did some online research and then I found out that it's a common problem on these models. I even found a guide to replace the resistor and "other component" although it didn't say which. Anyway, I started again to find the recurring fault, this time with the ballast powered, and manually turning it on (the protocol is quite simple), with the lamp connected. I first suspected the HV ignition circuit is bad (I did not have a way to test it live back then) but after some time spent getting to somehow know the circuit, I finally was able to find the fault. Another SMPS/PWM controller chip!!! This time it was the one controlling the power for the lamp. It's present on the logic daughterboard.


So, to summarize. After about 10-15 refurbished units over the years, I can say that ballast board is the number one fault on these models.

The ballast has 2 faults discovered by me.

1. Logic daughter board power supply failure (Resistor/SMPS chip blown, possible other surrounding components). If the logic board was affected by this, further repair might be needed.

Parts needed for repair:
4.7 Ohm resistor, 0.5w or more
LNK363DN
Check/replace electrolytic caps near LNK363 and LDO chip


2. SMPS chip for lamp power supply
Parts needed for repair:
M51995AFP

All the parts are common and you can find them at many places around the globe. For replacement you need a hot air gun for desoldering SMT components and a soldering iron/station.

Aside from this ballast problem and the capacitor from the IR boards which is mounted the wrong way from factory and will definitely fail sooner rather than later (easy fix, one time) , I still love my JVC projector.


Please note that this fixes only work for the faults described, if your ballast have a different fault, changing above mentioned parts will not cure it. Also, there's a risk of electric shock once you open the projector (even after you removed the power cable) so take the necessary measures to avoid nasty accidents.
View attachment 2658034 View attachment 2658036 View attachment 2658038


Thanks for writing this up. I was wondering if you are able to repair other people's as well? I have a JVC x3 that I bought a few days ago and it has the same issues with the ballast board that many people are experiencing. I have already taken out the ballast board, but I have not had much experience in diagnosing issues with each of the components parts. I was either going to buy a brand new board or have someone fix it who knows what they are doing.

Please let me know,

Thank you!
 

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Hi Cream. Thanks for your detailed information. I'm in the process of ordering parts for repair but need so clarification. In the description you first mention LNK364 but than refer to LNK363 in the parts list. I assume either is fine as the LNK364 is slightly higher current? Also for the 4.7ohm, is it SMD or axial form and what values of electrolytic caps are around the LNK and LDO devices? I couldn't find a schematic of the ballast board. Thanks.
 

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Hi, would this method work with the JVC X550R? The projector started to have the same sequence of light blinking. The standby light turn on green and ILA showed on the screen and the standby light immediately turned red and then the warning light also turn solid red along with the blinking orange lamplight. I did swap out the lamp but did not fix the issue.
 

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Hello Punks123.
I have the exact same problem with my JVC X5000. I believe the X5000 and the X550R are the same machines.
The JVC repairer in France, asks me 1350 € = 1600 $ for the repair. I do not know what to do.
 

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Hello Punks123.
I have the exact same problem with my JVC X5000. I believe the X5000 and the X550R are the same machines.
The JVC repairer in France, asks me 1350 € = 1600 $ for the repair. I do not know what to do.
The X500 is the X5000, or RS49, while the X550, or X5500, is the equivalent model of the following generation.

Anyway, ballast problems can occur to any projector. Although these models are not known for having this issue (like the 2010 and 2011 are), I've seen people who have had to replace the ballast on models of the same year as yours or punks123. Did the repairer tell you what the problem is? If he estimated a repair cost, he must be able to tell you what the problem is. If the problem is the ballast, it shouldn't cost that much to remove and replace/repair the ballast. I mean, for 1350 euros you can find a higher model than yours on the used market.
 

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Thanks for the response, i found few videos on you tube repairing the ballast and would give it a try once i have more times. I could the link if you want once i get home. I believed the ballast would cost about 294 u. dollars if i'm not mistaking.



Sent from my ONEPLUS A6003 using Tapatalk
 

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I just replaced a bad ballast on my JVC RS4910. If anyone is rebuilding these and would like my old one to work on, let me know. I’d be glad to send it to you.

THIS HAS BEEN CLAIMED
 

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Can you send it to me. Im looking forward to rebuild it. Can you send me a photo of it.

Sent from my ONEPLUS A6003 using Tapatalk
 

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I think I have a bad ballast. A new one cost me $300 shipped from Encompass Parts. I will be replacing within a week, so we will see what happens.
 

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Based on my experience, the fault involving M51995AFP chip is the number one fault, with 6 occurrences out of 10.


As for the caps, to properly measure them, you need an ESR meter, indeed. But the caps are pretty cheap and could be changed in case they had degraded. In my case, I didn't change them. They can appear fine visually, but their capacitance and/or internal resistance can vary outside tolerance.

Just wanted to say thank you. I had given up on this projector ever woking again. Been dead for 4+ years sitting on a shelf. I had already done number 1+ based on some info i had found previous to this post in early 2019. Still would not work. Found this post when i was thinking about just selling it for parts. Did fix number 2 and it turned right on and seems to be working fine so far
 

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I think I have a bad ballast. A new one cost me $300 shipped from Encompass Parts. I will be replacing within a week, so we will see what happens.
After hundreds of screws and removing or lifting just about every circuit boards on the right side (when looking at the front of the projector RS-45), I put everything back with no extra screws left! It powered on successful. Below is the link to the board I bought:


It was $267 + shipping + tax = ~$300. I have plenty of pics, and it looks just like a bowl of pasta. Regardless, I do have to give those JVC engineers a lot of credit on designing this projector. They probably didn't know that the ballast would go bad so frequently. Otherwise, they would have made an open like the lamp door replacement. If you're in Houston and need help, ping me while it is still fresh in my mind.
 

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