Re: Hitachi 42HXT12U - Not working - Standby LED Flashes
Appreciate you sending over that link but I ended up buying the £33 pack off Ebay.
So thanks for all your help mate - we're all working again now!
Saved another rebadged vestel from the tip....
Jack828
ultimate n00b
Last Activity: 12-19-2020, 01:04 PM
Joined: 12-13-2020
Location: Herts
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Re: Hitachi 42HXT12U - Not working - Standby LED Flashes
Awesome! Probably gunna have to buy a full set of LEDs as they seem to be cheaper than getting them individually.
Can't wait to get the dining room table back!Leave a comment:
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Re: Hitachi 42HXT12U - Not working - Standby LED Flashes
Yes, should've said.
I identify which traces are + and - by applying the multimeter in diode mode to each trace area using trial and error. When I've figured out which lights up an LED, I move to the next strip and try the same pads.
The marked LEDs do not light up when touching the same pads that lit up the LED on another strip.
(Of course, I had to do this twice, once for A strip and once again for C)
Hope that makes sense!Leave a comment:
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Re: Hitachi 42HXT12U - Not working - Standby LED Flashes
I did manage to test the LEDs individually - see attached for the believed broken ones....Leave a comment:
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Re: Hitachi 42HXT12U - Not working - Standby LED Flashes
Sure, makes sense.
Just plugged it in now and no LEDs lit up.
I'm guessing next steps is buy a LED strip pack and replace those?Leave a comment:
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Re: Hitachi 42HXT12U - Not working - Standby LED Flashes
So I am aware (and sorry again for the double posting!) what does it mean if the backlights either DO or DO NOT flash when powering the unit up without the panel in?
I assume if I have one or more dead LEDs that the LEDs will not flash at all, and if they do flash we have a power issue.Leave a comment:
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Re: Hitachi 42HXT12U - Not working - Standby LED Flashes
Yes, there is continuity between strips.
Haven't tried powering it up again yet but I'm pretty sure I've more than one blown led on almost each strip, just figuring out which is +ive and -ive traces is tricky - should have another update tonight.
EDIT: Looking at the moment that I need 3xA and 1xC strips.Last edited by Jack828; 12-15-2020, 08:05 AM.Leave a comment:
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Re: Hitachi 42HXT12U - Not working - Standby LED Flashes
Righto, managed to get the whole thing apart to check the LED strips.
Continuity between strips is fine, but putting the multimeter on diode mode and probing the little + and - test points doesn't make any of them light up at all.
EDIT: TIL, you can scratch the solder mask off and test each LED individually, just gotta figure out what goes where!!...Last edited by Jack828; 12-14-2020, 02:55 PM.Leave a comment:
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Re: Hitachi 42HXT12U - Not working - Standby LED Flashes
Gotcha. Will look into that to see if I can't just replace the faulty ones or if I have to get the all the strips. Thanks so much!Leave a comment:
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Re: Hitachi 42HXT12U - Not working - Standby LED Flashes
Sorry, my bad I managed to find it after looking again more closely - 393v.Leave a comment:
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Re: Hitachi 42HXT12U - Not working - Standby LED Flashes
C105 - 393v
CN501 - Black - Started at 80v, goes down to 11v, then jumps back to 80v after another power on
CN501 - Red - 118v, then jumps around between 180-190v
Roger that, lets hope not....Leave a comment:
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Re: Hitachi 42HXT12U - Not working - Standby LED Flashes
Sorry for the double post but I figured a way to measure whilst the unit is plugged in.
Here's the readings:
1 - PIN_1 - 0v off, 24.29v when powering up
2 - GND - ok
3 - ST_BY - floating, ~2v when powering up
4 - GND - ok
5 - BL_ON-OFF - 0v
6 - GND - ok
7 - PWM_DIM - 0v of, 3.3v when powering up
8 - GND - ok
9 - +5V_STBY - 5.3v
10 - +12VCC_S - can't reach whilst plugged in
11 - +12VCC_S - 12v bang on
12 - +12VCC_S - can't reach whilst plugged...Leave a comment:
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Re: Hitachi 42HXT12U - Not working - Standby LED Flashes
Not sure I follow what you mean?
It's pretty wacky to be honest. I unplugged the cable so I could get readings and I got this:
1 - PIN_1 - 0v
2 - GND - ok
3 - ST_BY - 0v
4 - GND - ok
5 - BL_ON-OFF - 0v
6 - GND - ok
7 - PWM_DIM - 0v
8 - GND - ok
9 - +5V_STBY - 0.1v
10 - +12VCC_S - varies between 7v and 11v, not stable at all
11 - +12VCC_S - same as above
12 - +12VCC_S - same as above...Leave a comment:
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Hitachi 42HXT12U - Not working - Standby LED Flashes
Hello fellow tech geeks!
I've recently come into possession (a freebie!) of a Hitachi 42HXT12U LED TV which does not work.
It does the following:
- Plug in
- Standby LED flashes alternating RED and BLUE approx 6-7 times
- Does this approx twice
- Standby LED stays solid BLUE
I've opened it up and had a look at the PSU board (which is a 17IPS20 23145828) for any bulging caps and there aren't any.
Any ideas folks? If you suggest replacing the PSU board then I'll go ahead and do it - only about 30 quid off... -
Re: New Members - please post your introductions here
Hey all! Joined to save my old tv from ending up in landfill. Lets hope we can fix it and provide the info for others to save their TVs!Leave a comment:
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