Sharp LC-80LE632U 2-5 blink code

[SdlewisSr]

I have a Sharp LC-80LE632U with a 2-5 blink code. I have narrowed it down to the T-Con/Panel. I get the error if both or either ribbon cable is connected between the T-Con and the Panel. If I disconnect both ribbon cables, I get no error and the TV powers up just fine.
Does anyone know if this is a definite bad Panel or is there a chance that the T-Con could still be at fault?

[SdlewisSr]

Re: Sharp LC-80LE632U 2-5 blink code

A little more background information. The initial blink code on this TV was (2-2) Power supply error 2 UR+13V error. I also noticed that buzzing sound in the PFC area. After checking the UR+13V filter caps and rectifiers and finding nothing wrong, I refreshed the solder joints on the major components (transformers, FET's, diodes, caps, large inductors). Then I took a look at the PFC and noticed that it was lower than I thought it should be and it fluctuated. When the PFC is off the voltage on the bridge rectifier/filter caps (C7220, C7222, C7223) was normal and did not fluctuate. When the PFC turned on the voltage on the filter caps fluctuated between 310v and 316v. Also the voltage on the bridge rectifier fluctuated between 150v and 220v. Even with this fluctuation the output voltages were stable and where they should be.
After refreshing the solder joints I put the power supply board back on the TV. Now the 2-2 blink code was gone but the 2-5 showed up.
Because of the 2-5 blink code, I check the T-Con/Panel. When I disconnected one or the other ribbon cable between the T-Con and Panel I still got the 2-5 blink code. When I disconnected both ribbon cables, the TV powered up as normal. The PFC remained the same. I expected the PFC to be around 380 - 400 volts, but it remained fluctuating near 300v.
What I am wondering is if the PFC is too low to handle the 12v outputs when the T-Con/Panel tries to power up, and this is why it's giving the 2-5 blink code and not because the Panel is bad.
Note: Though the PFC voltage does not increase when the TV comes up with the two Panel ribbon cables disconnected, the buzzing increases as the backlight intensity increases.

[lotas]

Re: Sharp LC-80LE632U 2-5 blink code

Here is a diagram of the power supply, it can help you figure it out.

[SdlewisSr]

Re: Sharp LC-80LE632U 2-5 blink code

Thanks lotas!!! This will be a big help.

[SdlewisSr]

Re: Sharp LC-80LE632U 2-5 blink code

Update: I fixed the low PFC voltage problem. I temporarily replaced the four 750k ohm SMD resistors (R7233, R7234, R7235, and R7236) off of pin 8 (HVSEN) of UCC28061 (IC7201) with four through hole 750k ohm resistors. Now all voltages are good. The PFC voltage is stable at 390v. Also the buzzing is gone.
However, that did not fix the 2-5 blink code. With the two ribbon cables (or just with one or the other) connected between the panel and T-Con board I get the 2-5 blink code. With both ribbon cables disconnected the TV comes up with no error, backlights and all.
Thanks again lotas for the board schematic!!!!

[lotas]

Re: Sharp LC-80LE632U 2-5 blink code

Please, was glad to help

[SdlewisSr]

Re: Sharp LC-80LE632U 2-5 blink code

Update: I checked some of the main voltages on the T-Con board at connectors SC7001 & SC7002 without it connected to the Panel. I also checked the resistance to ground of these same pins with the T-Con disconnected from the Panel and then again with the T-Con connected to the panel. (See attached chart)
The voltages appeared to be normal. Only the Vcom pin resistance changed a lot. This may be normal.
I'm now wondering if the 12v regulator (IC7504) on the Power Supply board is failing under load.

[SdlewisSr]

Re: Sharp LC-80LE632U 2-5 blink code

Update: I put a 4.5 ohm load on the PNL12v and ran it at 2.67 amps for a few minutes and it did not fail under this load. The 12v regulator (IC7504) is rated for 3 amps. I'm not sure how many amps the Panel runs at under normal conditions, but I'm no longer suspecting the 12v regulator is failing under load.

[SdlewisSr]

Re: Sharp LC-80LE632U 2-5 blink code

Close out this thread: After reading the Sharp Aquos LC-70LE732U Blinking Pattern 2 -5 thread (https://www.badcaps.net/forum/showthread.php?t=45671) and finding the Sharp Tech Tip # 1541 (https://www.badcaps.net/forum/attach...5&d=1429113014), I am concluding that the Panel is bad. Therefore I am closing out this thread.

[R_J]

Re: Sharp LC-80LE632U 2-5 blink code

The panel IS likely bad, but, there are options to try, There may be a shorted mlcc on one of the panel boards, there may be a bad panel driver ic on the side tabs that in some cases can be removed to restore the panel to a watchable tv. I don't know which threads to check but the information is here somewhere,

[budwich]

Re: Sharp LC-80LE632U 2-5 blink code

Close out this thread: After reading the Sharp Aquos LC-70LE732U Blinking Pattern 2 -5 thread (https://www.badcaps.net/forum/showthread.php?t=45671) and finding the Sharp Tech Tip # 1541 (https://www.badcaps.net/forum/attach...5&d=1429113014), I am concluding that the Panel is bad. Therefore I am closing out this thread.

:-( I know you have done a lot.... BUT with the more recent work that you did for "voltage improvements", have you tried getting into the service menu. You might have to reset counters therein.

[SdlewisSr]

Re: Sharp LC-80LE632U 2-5 blink code

The panel IS likely bad, but, there are options to try, There may be a shorted mlcc on one of the panel boards, there may be a bad panel driver ic on the side tabs that in some cases can be removed to restore the panel to a watchable tv. I don't know which threads to check but the information is here somewhere,

Thanks R_J for the idea! Do you think a shorted mlcc on one of the driver boards would have shown up when I checked the resistance to ground with the T-Con disconnected from the Panel and then again with the T-Con connected to the panel (see attached chart)?

[SdlewisSr]

Re: Sharp LC-80LE632U 2-5 blink code

:-( I know you have done a lot.... BUT with the more recent work that you did for "voltage improvements", have you tried getting into the service menu. You might have to reset counters therein.

Hi budwich. With either or both ribbon cable connected between the T-Con and the Panel, it does not power up and I get the 2-5 blink code. When I disconnect both ribbon cables the TV powers up with backlights, but of course there is nothing going to the Panel.

[budwich]

Re: Sharp LC-80LE632U 2-5 blink code

yes BUT, there is a "force sequence" when there is a fault code. Does that work? Note: those links that you posted are some what dated in terms of what people have found to work and not work with sets. Having said that, iirc, the 80 is a bit different from other sets in having the panel disconnected.... where as others allow to have part of the panel disconnected and still somewhat function.

[SdlewisSr]

Re: Sharp LC-80LE632U 2-5 blink code

yes BUT, there is a "force sequence" when there is a fault code. Does that work?

Thanks! I look into how to do that and try it.

[budwich]

Re: Sharp LC-80LE632U 2-5 blink code

I hate to see an 80 incher in the garbage. Your measurements listing in post 12 seem to suggest a possibly issue with the vcom circuit. You might see if you can visually or otherwise trace the circuit therein at the panel. IF you are lucky, you might find a compromised SMD component... most have found shorted caps in these areas that can be replaced with some careful soldering. IF you post a close up picture of the panel connection area at the connector and highlight where vcom is, others might have more ideas.
Further about disconnecting the tcon from the panel... that is somewhat a "gross test" which basically takes out large portions of the panel circuitry / control system. IF you look along the bottom of the panel, there are long thin driver boards which the tcon connects to. There is likely a pair of boards on one side of the panel and another pair on the other side (ie. one for each tcon to panel ribbon cable). The pair of driver boards have an "unclampable / clampable" "U" ribbon cable interconnecting them. With all other cables left connected, disconnect one of the "u" cables (ie. in essence, isolating 1/4 of the panel... the outer 1/4). See if the set responds differently to being powered up. Repeat the same test, on the other side. Any difference? Note: only one "U" disconnected at a time. IF you are lucky, you may see some screen happening. Go from the results.

[SdlewisSr]

Re: Sharp LC-80LE632U 2-5 blink code

I hate to see an 80 incher in the garbage. Your measurements listing in post 12 seem to suggest a possibly issue with the vcom circuit. You might see if you can visually or otherwise trace the circuit therein at the panel. IF you are lucky, you might find a compromised SMD component... most have found shorted caps in these areas that can be replaced with some careful soldering. IF you post a close up picture of the panel connection area at the connector and highlight where vcom is, others might have more ideas.
Further about disconnecting the tcon from the panel... that is somewhat a "gross test" which basically takes out large portions of the panel circuitry / control system. IF you look along the bottom of the panel, there are long thin driver boards which the tcon connects to. There is likely a pair of boards on one side of the panel and another pair on the other side (ie. one for each tcon to panel ribbon cable). The pair of driver boards have an "unclampable / clampable" "U" ribbon cable interconnecting them. With all other cables left connected, disconnect one of the "u" cables (ie. in essence, isolating 1/4 of the panel... the outer 1/4). See if the set responds differently to being powered up. Repeat the same test, on the other side. Any difference? Note: only one "U" disconnected at a time. IF you are lucky, you may see some screen happening. Go from the results.

Thanks budwich for the suggestions!!!!
I look forward to checking these out.

[RDC55]

Re: Sharp LC-80LE632U 2-5 blink code

Update: I checked some of the main voltages on the T-Con board at connectors SC7001 & SC7002 without it connected to the Panel. I also checked the resistance to ground of these same pins with the T-Con disconnected from the Panel and then again with the T-Con connected to the panel. (See attached chart)
The voltages appeared to be normal. Only the Vcom pin resistance changed a lot. This may be normal.
I'm now wondering if the 12v regulator (IC7504) on the Power Supply board is failing under load.

You mention the resistance changed, but how about the voltage between panel connected and disconnected? Maybe I missed it but if one is loading that could lead you down a logical path, particularly if that voltage loads with either TCON output ribbon cable connected.

[SdlewisSr]

Re: Sharp LC-80LE632U 2-5 blink code

You mention the resistance changed, but how about the voltage between panel connected and disconnected? Maybe I missed it but if one is loading that could lead you down a logical path, particularly if that voltage loads with either TCON output ribbon cable connected.

With both cables connected, from the time I plug it in until I get the 2-5 blink code and it shuts down, I have 12v coming to the board at P4804, but no voltages on Pins 11,12 (VDA/AVDD, Pins 33,34 (VDD/Logic), Pin 60 (Vcom), Pin 78 (VGH), and Pin 79 (VGOFF/VGL) at connectors SC7001 & SC7002 .

[SdlewisSr]

Re: Sharp LC-80LE632U 2-5 blink code

yes BUT, there is a "force sequence" when there is a fault code. Does that work? Note: those links that you posted are some what dated in terms of what people have found to work and not work with sets. Having said that, iirc, the 80 is a bit different from other sets in having the panel disconnected.... where as others allow to have part of the panel disconnected and still somewhat function.

When I hold the [Vol+] and [Chan-] while plugging in the TV, I do not get the 2-5 blink code, and the TV does not shut down, but the backlights do not come on. The 12v coming to the board at P4804 remains on, but no voltages on Pins 11,12 (VDA/AVDD), Pin 60 (Vcom), Pin 78 (VGH), and Pin 79 (VGOFF/VGL) at connectors SC7001 & SC7002. However, I do have a small voltage of .658v on Pins 33,34 (VDD/Logic).