Re: JVC JLC42BC3000 screen froze on "JVC" logo.
I'll make some local calls and see what I find out. I saw the EEPROM sold for ~$30 as a kit with 2 caps. Thank you again, nomoresonys.
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Last Activity: 11-19-2020, 09:09 PM
Joined: 06-11-2019
Location: Urbana, Illinois
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Re: JVC JLC42BC3000 screen froze on "JVC" logo.
Thank you nomoresonys and Davi.p. I did try all the tricks suggested in this forum. Nothing worked. I even replaced 6 electrolytic caps, although they were not really puffed up, but their tops "might" have not been perfectly sealed when viewed with a magnifying glass. Still the stuck-on-JVC-logo persists.
I showed the U12 EEPROM on the main CB, which has 48 tiny pins, to the local repairman and he changed his mind. He said that he thought that the EEPROM was similar to others he was familiar with, which...Leave a comment:
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Re: JVC JLC42BC3000 screen froze on "JVC" logo.
Davi.p, I guess a better question than my last one would be: what is the label on the main CB for the EEPROM? And is it on the top or bottom side of the CB? That would certainly identify it uniquely and clear my confusion.Leave a comment:
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Re: JVC JLC42BC3000 screen froze on "JVC" logo.
Davi.p, Sorry for not seeing this earlier. I used to get an email message whenever something new would be posted, but I have not gotten any for this! Thank you for the reply. I can connect the TV to the serial port of a PC running Windows (either XP, or 7, and maybe 10). Will that also give me an informative log file? If yes, will the file come up automatically, or will I need to issue any commands in a window that may open?
Could you, please, clarify: Is the EEPROM for this JLC42BC3000 TV the square component...Leave a comment:
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Re: JVC AV-27750 IR Sensor Problem
Just an idea: Does anybody know, if I were able to find an IR sensor that operates at the same frequency as the one of my TV and has the same Vcc and Vout voltages, would I be able to use it without the tiny CB and metal housing of the original IR sensor (shown in photos posted earlier)?Leave a comment:
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Re: JVC JLC42BC3000 screen froze on "JVC" logo.
Update on the stuck-on-JVC-logo problem: Davi.p, I have checked the soldering and the ESRs of the new caps. All OK.
As I mentioned earlier, I had given up trying to fix my main CB and ordered a "new" board from Ebay seller, who claimed that the board was removed from a working TV with broken screen. Well, the CB was shipped in an envelope, instead of a box! Most caps were bent badly. The seller sent me a prepaid label to return the CB and have it replaced. I asked that the replacement CB be shipped...Leave a comment:
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Re: JVC JLC42BC3000 screen froze on "JVC" logo.
Update on Feb. 4, 2020: I got tired of waiting to find an EEPROM, so I just bought a new Main CB. Hopefully, it will fix the problem.
BTW, I asked two ebay sites, which say they'll repair the Main CB to get rid of the stuck-on-JVC-logo problem, what they'll do, but neither replied! Most state laws say that, not only do they have to tell a customer what they'll do and give an estimate, but they also have to return the defective part to the customer if asked to do so. Ebay offers no way to report this illegal behavior...Leave a comment:
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Re: JVC AV-27750 IR Sensor Problem
Thank you, budm, for the fast and informative reply. I cannot understand all the information in the pdf file (I am a beginner), but the HC-337M is there! The data sheet lists its frequency as being 37.9 kHz. Does anybody sell this IR sensor?
In response to your question, I do not have an oscilloscope to look at the output pin. Before removing the Front Control CB, on which the IR sensor resides, I tried to measure the output voltage with a DMM while the TV was on, but I heard scary click-click sounds, as if I was causing a short...Leave a comment:
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JVC AV-27750 IR Sensor Problem
In addition to 2 flat-screen TVs, I own a 27" CRT (reliable!) TV (JVC AV-27750), connected to a Converter Box. A few days ago, its IR sensor stopped working. It does not respond to any button of the Remote Control. The remote control works fine (I can see it flashing through a cell phone's camera), and a capacitor and a resistor near the IR sensor have the correct values. I desoldered and removed the IR sensor from the small Front Control CB. It has a metal cover -- please, photos. It has two numbers on the metal cover: HC-337M (which the Service Manual identifies as the part number and)... -
Re: JVC JLC42BC3000 screen froze on "JVC" logo.
Thank you, nomoresonys. I'll look into that.Leave a comment:
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Re: JVC JLC42BC3000 screen froze on "JVC" logo.
diif, No. My main board is different. Please, see attached photo....Leave a comment:
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Re: JVC JLC42BC3000 screen froze on "JVC" logo.
Thank you, nomoresonys. I cannot find an EEPROM, however, and, as I mentioned in #50 posting, JVC is incredibly unhelpful.Leave a comment:
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Re: JVC JLC42BC3000 screen froze on "JVC" logo.
Yes, I tried freezing the NAND FLASH. It made no difference. (If it were/is the problem, I am not skillful enough to replace it. The EEPROM, I think I would manage to replace.)Leave a comment:
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Re: JVC JLC42BC3000 screen froze on "JVC" logo.
Well, RJ and nomoresonys were right. The "stuck-on-JVC-logo" problem returned, after 3 weeks of the TV turning on normally. So, the two caps I replaced that fixed the problem were a symptom, not the root cause of the problem. (They are still good, but the TV is not turning on normally.)
I called JVC and asked whether I could download either the original firmware or an update, but the man with whom I spoke was of no help. I asked to talk with a technical/service person, but he refused to let me do that!...Leave a comment:
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Re: JVC JLC42BC3000 screen froze on "JVC" logo.
budm, Thank you for all the links/references. I am slowly reading, and learning a lot. Grateful.Leave a comment:
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Re: JVC JLC42BC3000 screen froze on "JVC" logo.
First, I think that RJ and nomoresonys are probably correct. Although I know very little about TVs, I do know about computers. It appears to me that the "stuck-on-JVC-logo" problem is very similar to a computer getting stuck at bootup. In the latter case, it is almost always a problem with the BIOS (e.g., the order of bootup devices getting changed, or a peripheral device is no longer recognized, etc. It is seldom a hardware problem on the motherboard, although that is also possible). Since the EEPROM/Firmware of...Leave a comment:
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Re: JVC JLC42BC3000 screen froze on "JVC" logo.
budm, thank you. I gave a detailed reply to your suggestions, but, after I clicked "Post Quick Reply", the website asked me to sign-in again, and all the text was gone! I'll reconstruct it later, hopefully late tonight. I'll make sure I write it on my computer first, and then cut-and-paste. I didn't know the website would do that.Leave a comment:
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Re: JVC JLC42BC3000 screen froze on "JVC" logo.
Thank you budm & RJ for the VERY helpful responses.
Next time I remove the TV back cover, I'll "practice" removing the small ribbon cable. Fortunately, I managed to replace the CE1 and CE22 caps w/o disconnecting or breaking it!
Indeed, the labels I read on D201 and D202 could be incorrect. The letters/numbers are very faint and, worse yet, the caps in front of them do not allow direct viewing. I used a flash light and even a dentist's mirror to get those. A photo of D201 and D202...Leave a comment:
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Re: JVC JLC42BC3000 screen froze on "JVC" logo.
Thank you, budm. I will when I have the opportunity to open the TV up again.
I have difficulty identifying the three components that are attached to the relatively large heat sink on the upper right quadrant of the PSU (please, see photo). I copied their labels and tried to identify them by searching online. They are:
Q201: 1615AU FQPF 13N06L. Online search found this to be a MOSFET.
D201: MBRF 10U160CT 122. Online search yielded nothing!
D202: MBRF 20U165CT 104 Online search...Leave a comment:
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Re: JVC JLC42BC3000 screen froze on "JVC" logo.
Well, since I did not know how to disconnect that little ribbon cable (see last posting), but I wanted to try to fix the "stuck at JVC logo" problem, I carefully turned the main CB upside down and rested it on a soft foam slab. (I had tried all the things recommended on this site, but nothing made the TV turn on normally. However, I had noticed that the capacitances of CE1 and CE22 on the main CB were unsteady with no power applied to the TV. I was aware that one cannot measure capacitance reliably while the cap...Leave a comment:
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