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Wodger replied to Sharp LC-40UG7252K black screen

in Troubleshooting TVs and Video Sources

07-06-2024, 04:59 AM
Hi everyone,

So, after a horrible trip to Turkey (not for pleasure sadly), I'm back and keen to get this board working properly.
I'm stuck with what resistor value I need to fit to replace the blown SMD R218.

Attached is the screen grab section of the schematic but it doesn't list values for the relevant components. Is anyone able to advise?

Thanks,

Pete...

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Wodger replied to Sharp LC-40UG7252K black screen

in Troubleshooting TVs and Video Sources

06-14-2024, 10:58 AM
Hi everyone,

So, had some time to look at this. Appears backlight issue as after throughly cleaning screen (disgusting!) sharp logo and "no signal" visible with flashlight.

Found layout schematic for psu board which I have attached here for others should they have the same psu board (appears common for sharp TVs).

While I was tracking down the problem and finding no 380v passing through q201, but 120v on gate, I inadvertently caught the leg with my probe and blew R218 (teach me also to take picture of back of board for correct value replacement...

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Wodger started a topic Sharp LC-40UG7252K black screen

in Troubleshooting TVs and Video Sources

06-10-2024, 01:13 PM
Sharp LC-40UG7252K black screen

Good day all,

As title says, black screen. Replaced hot side and largest cold side capacitors on power board as were reading erratic and TV was dead (no power light).

Following replacement, power led now illuminates, changes from red to blue on pressing TV joystick, still black screen. Connection board appears powered (optical sound led on). Slight crackling from speakers.

Checking led driver voltage reveals voltage falls off after power on from pressing joystick (drops to zero).

Attached picture of power board.

Next check steps...

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Wodger replied to Electrolux EWT904 (Simpson brand) - Top Loader Washing Machine

in Troubleshooting Appliances and other Household Electronic Stuff

02-05-2024, 08:24 AM
Thats good to know, one less purchase. the varistors though, from what I've seen online, I should have some sort of reading with a multimeter, but I have nothing, not even a short.

Regarding the board, everything on the hot side has been removed and checked save for the 2 inductors (I'll check on them first thing tomorrow).

Pete...

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Wodger replied to Electrolux EWT904 (Simpson brand) - Top Loader Washing Machine

in Troubleshooting Appliances and other Household Electronic Stuff

02-05-2024, 02:56 AM
Hi everyone,

So after removing the remaining 0.1uf capacitor / varistor / PTC on the ac line, found the PTC actually has "leaked" so I'm pretty confident that's dead, the yellow 0.1uf capacitor also appears dead giving open circuit on terminals, also dead is 470uf and 100uf electrolytic capacitors which don't appear to charge and remain shorted (going by analog multimeter). The varistors are a puzzle, I should have some sort of reading, but I get nothing from any of them.

The rest of the parts appear fine (checked SCR's, the 5V regulator, diodes, the voltage...

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Wodger replied to Electrolux EWT904 (Simpson brand) - Top Loader Washing Machine

in Troubleshooting Appliances and other Household Electronic Stuff

02-04-2024, 10:55 PM
So I unsoldered the parts you circled plus the switcher (it made it so much easier to remove the silicone gunk from the board). And cleaned the board up as best as I could.
I tested the small smd resistors and capacitors on the back to the ac line 2 for continuity on either side and all but a couple sounded on connected side only (the remaining ones didn't sound at all) - I also tested the chunky smd diode and that appears working normally (first time I have seen a 2nd band on a diode casing - I'm not deep electronics specialist - trained in marine engineering).

Short stop for...

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Wodger replied to Electrolux EWT904 (Simpson brand) - Top Loader Washing Machine

in Troubleshooting Appliances and other Household Electronic Stuff

02-03-2024, 07:41 PM
Hi mate,

Thanks for that😊I was just about to head out to do the jobs for the day. Attached is a closeup picture looking from the right side of your markup picture showing the part number of the question marked part. Hopefully, I have energy later to look at this as the laundry is building up.😂

Pete...

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Wodger replied to Electrolux EWT904 (Simpson brand) - Top Loader Washing Machine

in Troubleshooting Appliances and other Household Electronic Stuff

02-03-2024, 09:44 AM
Cheers for the advice - I will get back on this probably tomorrow night if I get energy (troubleshooting a Kia that is now refusing to start). Regarding your question what device is there, I assume your looking at the arrowed area on attached pic? - Diodes - I will of course make sure they are working properly.

I will advise of my findings.

Pete...

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Wodger replied to Electrolux EWT904 (Simpson brand) - Top Loader Washing Machine

in Troubleshooting Appliances and other Household Electronic Stuff

02-02-2024, 10:30 PM
Good day,

Thanks for responding. Attached are pictures of the board. I'm without power at the moment for another 6 hours and lighting and board design doesn't lend well to pictures (circuitboard is encased in a clear rubberized silicone material which makes repair of this board a headache). I have done top and bottom and then front and both sides.
From my investigation, the ptc resistor on the ac incoming line gets really hot to touch within 20 seconds of power applied.
The machine was functioning normally during a cycle then after draining was about to spin when the supply...

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Wodger started a topic Electrolux EWT904 (Simpson brand) - Top Loader Washing Machine

in Troubleshooting Appliances and other Household Electronic Stuff

02-01-2024, 04:28 AM
Electrolux EWT904 (Simpson brand) - Top Loader Washing Machine

Hi Everyone,

I'm looking for a circuit diagram layout for the power board on this machine, so I can attempt to troubleshoot, As per the sicker on the back:

SIMPSON/Electrolux
W2104A-V06

I've repaired and replaced this board once but now I have 2 dead powerboards. Usually the capacitors blow on this design, but recently I found no problems with the capacitors and finally found the offline switcher (LNK306PN) had burned. On replacement, one board worked for a while but now is dead again (no beep when powered up from wall supply), and the other older board...

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Wodger replied to Troubleshooting a Toshiba LCD TV. Model 40AV700E

in Troubleshooting TVs and Video Sources

01-08-2024, 07:18 PM
Hi,

Thanks for getting back to me.

Voltage on both sides of fuse "F1" 0v

Pete...

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Wodger replied to Troubleshooting a Toshiba LCD TV. Model 40AV700E

in Troubleshooting TVs and Video Sources

01-05-2024, 02:09 AM
Apologies for the delay (too many things broke over new year so got busy).

Attached is a picture of the TCON board.

Regards,

Pete...

1 Photo

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Wodger replied to Troubleshooting a Toshiba LCD TV. Model 40AV700E

in Troubleshooting TVs and Video Sources

12-27-2023, 07:44 PM
Gentleman,

I have 3 boards visible on this TV, 1 main powerboard (top post), what I assumed to be the TCON board but is actually the mainboard (post 6) - thats what happens when its nearly midnight and your tired. The TCON board is hidden behind a backplate at the top of the screen and I will get a picture once I get back to it later.

According to the manual supplied by Diah (post 7), 12V appears to be supplied to the mainboard from the powerboard and again due to misunderstanding, I measured on the mainboard incoming supply from power board and cut down picture is of...

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Wodger replied to Troubleshooting a Toshiba LCD TV. Model 40AV700E

in Troubleshooting TVs and Video Sources

12-27-2023, 09:50 AM
Following back to transformer from hot to cold - "TM802S" on power board appears no 12V output on secondary side pins...

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Wodger replied to Troubleshooting a Toshiba LCD TV. Model 40AV700E

in Troubleshooting TVs and Video Sources

12-27-2023, 09:37 AM
1. Searched drawing and board for fuse on TCON board, couldn't spot. Attached picture showed where I tested on T-Con board input from power board - marked values - readings the same both sides of SMD's
2. Used HDMI input from Rpi playing video (started with another screen then swapped HDMI cable to TV), no sound or picture observed with flashlight.

Going by results of 1. 12V side supply to TCON from powerboard appears an issue?

Pete...

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Wodger replied to Troubleshooting a Toshiba LCD TV. Model 40AV700E

in Troubleshooting TVs and Video Sources

12-26-2023, 08:11 PM
Good Day,

Using your advice about toshiba naming IC101 as SPI and the service manual you provided, I confirm 3.3v present on VCC pin 8 for SPI "IC101" in standby and on state

(I went for IC103 originally and had 3.3v on there also but then checked your manual and realized I had wrong one 😅 ).

Now for the other jobs for the day,

Pete...

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Wodger replied to Troubleshooting a Toshiba LCD TV. Model 40AV700E

in Troubleshooting TVs and Video Sources

12-26-2023, 10:17 AM
Thanks for this, it's late here (+12am), I will have a closer look tomorrow.

My background is marine engineering, so not in depth with deep electronics - but I will hunt for the SPI chip and its supply of 3.3v once other jobs are out the way tomorrow.

Pete...

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Wodger replied to Troubleshooting a Toshiba LCD TV. Model 40AV700E

in Troubleshooting TVs and Video Sources

12-26-2023, 09:04 AM
Attached picture of mainboard

What would be required to make an interface for capturing the log? Assuming the interface port is the 5 pin top right corner? (the 3.5mm jack by 15pin VGA connection is audio out for that PC connection)

Pete...

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Wodger replied to Troubleshooting a Toshiba LCD TV. Model 40AV700E

in Troubleshooting TVs and Video Sources

12-26-2023, 07:41 AM
I have had a look for the firmware online - Dr-Bios offers a firmware locked behind a paywall, the toshiba sites (both) do not list this model. Google doesn't seem to have the firmware listed anywhere either.

Anyone who has a firmware dump that could provide would be appreciated.

Thanks,

Pete...

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Wodger started a topic Troubleshooting a Toshiba LCD TV. Model 40AV700E

in Troubleshooting TVs and Video Sources

12-26-2023, 04:23 AM
Troubleshooting a Toshiba LCD TV. Model 40AV700E

Hi everyone,

Short story, I was asked to look at this TV by a close friend. Originally, the TV screen would go off after a random amount of time, unplugging it from the wall for a while and then powering on again usually would bring it back to life. Here in the Philippines, power interruptions are regular. Having experienced a similar state with my LCD monitor for PC (blown caps), I had a look at the power board - 2 caps were bulged and I replaced all.

The TV apparently worked for a while (few days) then it started acting up again. On another inspection, everything looked...

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