JVC JLC42BC3000 screen froze on "JVC" logo.

[Langston]

Hi, I'm trying to repair the logic board " 3642-1302-0150 " on my JVC LCD tv. I'm looking for any help possible. I've repaired another in the past by mailing off the logic board but I'm more interested in learning how to repair it myself. I have the back cover removed, multi-meter, pencil, paper, and a double shot of espresso ready in hand. I do not see any puffed capacitors or burn marks. Currently the screen lights up and the JVC logo sits in the screen. No buttons work and TV only powers down if I unplug it. Where should I start? Thank you in advance-
Langston

[Langston]

Re: JVC JLC42BC3000 screen froze on "JVC" logo.

Attached pictures-

[budm]

Re: JVC JLC42BC3000 screen froze on "JVC" logo.

http://www.shopjimmy.com/catalogsear...VC+JLC42BC3000

There are at least two fuses on that main board that I can see, also Voltage regulator ICs that you need to check.

Pictures provided by shopjimmy.
Read the link below my signature on how to test and report the readings that will be easy for us to understand.
BTW, the main board is made by AMTRAN which is the same company that makes board for VIZIO which has history of bad Voltage regulators 1117 series. This JVC is just a rebadged.

[Langston]

Re: JVC JLC42BC3000 screen froze on "JVC" logo.

Hi, I'm trying to repair the logic board " 3642-1302-0150 " on my JVC LCD tv. I'm looking for any help possible. I've repaired another in the past by mailing off the logic board but I'm more interested in learning how to repair it myself. I have the back cover removed, multi-meter, pencil, paper, and a double shot of espresso ready in hand. I do not see any puffed capacitors or burn marks. Currently the screen lights up and the JVC logo sits in the screen. No buttons work and TV only powers down if I unplug it. Where should I start? Thank you in advance-
Langston

http://www.shopjimmy.com/catalogsear...VC+JLC42BC3000

There are at least two fuses on that main board that I can see, also Voltage regulator ICs that you need to check.

Pictures provided by shopjimmy.
Read the link below my signature on how to test and report the readings that will be easy for us to understand.
BTW, the main board is made by AMTRAN which is the same company that makes board for VIZIO which has history of bad Voltage regulators 1117 series. This JVC is just a rebadged.

Thank you budm. I assume the fuses your talking about are F1 and F2?

F1=5.28VDC on both sides of gold terminals
F2=12.29VDC on both sides of gold terminals

These are the voltage regulators that I located, there may be more that I'm not seeing.
1084-VI= 5.22VDC VO=3.28VDC GND=2.05VDC (U5)
1117 #U9: In=5.23VDC Out=3.28VDC ADJ=2.02
1117 #U3: In=5.26VDC Out=3.29VDC ADJ=2.04
949D32: In=12.25VDC GRN=0.00 Out=5.04 (U17)
Also (U5) 1084 only has 2 of the 3 pins attached to the board. I've attached a picture showing this. the voltage on the detach and on the solder point are both the same. It may be designed this way.

Here are the voltages for the 14 pin connecter:

VBR_B - 3.22VDC - Orange

Status - 0.0VDC - Red

On/Off - 2.63 - Brown

On/Off - 3.18 - Black

12V - 12.27 VDC - White

12V - 12.27 VDS - Grey

12v - 12.26 - Purple

GND - 0.01VDC -Blue

GND - 0.01 VDS - Green

GND - 0.01 VDC - Yellow

GND - 0.01VDC - Orange
5.2VSB - 5.8 VDC - Red

5.2VSB - 5.29 VDC - Brown

5.2VSB - 5.28VDC - Black

[CapLeaker]

Re: JVC JLC42BC3000 screen froze on "JVC" logo.

you have an ESR meter or an oscilloscope to check the caps?

[budm]

Re: JVC JLC42BC3000 screen froze on "JVC" logo.

"5.2VSB - 5.8 VDC - Red" This one is probably an error because the other two are the same.
Your Voltages look normal but I do not know what the status pin is should be HIGH or LO for normal operation, right now it is sitting LO.

[retiredcaps]

Re: JVC JLC42BC3000 screen froze on "JVC" logo.

One ebay seller sells a service to repair the main board with exact symptoms. OP might want to send an ebay PM asking what part is replaced? Eeprom? main IC?

http://www.ebay.com/itm/252044041215

Shopjimmy, when searching for 3642-1542-0150 returns, (possibly an eeprom problem)

http://www.ebay.com/itm/251317871119

Caps on main board still could be bad and have too much ripple which might have caused the eeprom to go corrupt?

[retiredcaps]

Re: JVC JLC42BC3000 screen froze on "JVC" logo.

BTW, the main board is made by AMTRAN which is the same company that makes board for VIZIO which has history of bad Voltage regulators 1117 series. This JVC is just a rebadged.

Vizio also has numerous eeprom problems.

[Langston]

Re: JVC JLC42BC3000 screen froze on "JVC" logo.

Thanks everyone for the replies. After doing some more digging it seems it most likely is an eeprom issue. I called shop jimmy to try and purchase one but they do not carry them. They also said given the symptoms its most definitely an eeprom. I think I see several eeprom's on the main board but I'm not sure. Is there a way to test them to see which is faulty? Do I just start shooting in the dark and replacing one by one? Is there a inexpensive reliable source for these? Thanks again!
D-

[vinceroger69]

Re: JVC JLC42BC3000 screen froze on "JVC" logo.

maybe send these a email see if they do one for your main board
http://www.ebay.com/itm/EEPROM-FOR-J...item3a814cdf0e

[Langston]

Re: JVC JLC42BC3000 screen froze on "JVC" logo.

maybe send these a email see if they do one for your main board
http://www.ebay.com/itm/EEPROM-FOR-J...item3a814cdf0e

Thanks! I sent them a message this morning. Is it possible to test an eeprom with a multi-meter?

[vinceroger69]

Re: JVC JLC42BC3000 screen froze on "JVC" logo.

not that i know of? they store user data etc, so come pre programmed etc although some times you can re programme them yourself.

[Langston]

Re: JVC JLC42BC3000 screen froze on "JVC" logo.

I was able to talk to Ablemantv but as suspected this is how they make a living and he is not willing to tell me the solution. Also they do not sell an eeprom for this tv. I really don't want to give up but Im running out of options..

[CapLeaker]

Re: JVC JLC42BC3000 screen froze on "JVC" logo.

try to freeze the eeprom (can of air upside down) and turn the TV on. See what happens...

[Langston]

Re: JVC JLC42BC3000 screen froze on "JVC" logo.

try to freeze the eeprom (can of air upside down) and turn the TV on. See what happens...

Your on to something! I first tried freezing the eeproms (or what I think are the eeproms) and no luck so in frustration I sprayed the entire board plugged it in and the logo went away and it went on to "no signal" and worked perfectly. I used the power off button and it turned off normally. No again it is stuck on the Jvc logo. I tried to isolate the problem by freezing in sections and trying to turn it on but no luck. What could this mean? Thanks!

[CapLeaker]

Re: JVC JLC42BC3000 screen froze on "JVC" logo.

an eeprom MAY work again if cooled good enough. That trick doesn't work on every eeprom, but it does work on a large percentage. You can apply that trick too on a bad eeprom that you want to read out and then program a new eeprom with the retrieved data. So you don't need to go ".bin" hunting.

[Langston]

Re: JVC JLC42BC3000 screen froze on "JVC" logo.

an eeprom MAY work again if cooled good enough. That trick doesn't work on every eeprom, but it does work on a large percentage. You can apply that trick too on a bad eeprom that you want to read out and then program a new eeprom with the retrieved data. So you don't need to go ".bin" hunting.

I've isolated the area to this corner of the board near the HDMI inputs. Still can't pinpoint the exact problem. If I freeze individual components it doesn't boot but if I freeze the whole corner it boots and works properly. Any idea what component would be fixed by freezing on this corner?
See attachement-

[budm]

Re: JVC JLC42BC3000 screen froze on "JVC" logo.

I wonder if the HDMI chip is locking up the processor. How hot does the chip get?

[Langston]

Re: JVC JLC42BC3000 screen froze on "JVC" logo.

I wonder if the HDMI chip is locking up the processor. How hot does the chip get?

Thanks budm, Which is the HDMI chip in the picture you provided from shopjimmy? Also what is the round (capacitor??) CE39?

[budm]

Re: JVC JLC42BC3000 screen froze on "JVC" logo.

U18 (80-PIN IC), what is the P/N as printed on the top of the IC?
CE39 is the SMD lytics cap.