Sharp 32CHF5111K (TP.MS3463S.PB711) Fault

[sickboy]

I'm wondering if anyone can help me out with this repair?

Nice Sharp 32". This powers on and the little LED flashes red for a few seconds, then turns white as normal to signify that it's now on.

There's no backlight though and as far as I can see there's no image on the screen. I've stripped the screen and tested the backlight strips and they all light up ok using the tester. Another symptom is that the TV will not switch to standby.

Voltages I tested were 330v across mains filter cap and 42v between the backlights positive output and ground. There's no boost voltage when first powered on either. All diodes test out ok.

Any help gratefully appreciated.

[CapLeaker]

Re: Sharp 32CHF5111K (TP.MS3463S.PB711) Fault

Put your TV back together, unhook the main board from the PSU and force the PSU on. Use 1k resistors and jump STBY over to PSon, BLon and maybe even the DIM signal. Plug the TV in and the PSU should be fully on and the backlights too.

[R_J]

Re: Sharp 32CHF5111K (TP.MS3463S.PB711) Fault

How do you expect him to disconnect the main from the power supply when it is a single board???? get out the saw?

Check if you have +12v on UB801 pin 1, that is the ic's vcc

[sickboy]

Re: Sharp 32CHF5111K (TP.MS3463S.PB711) Fault

Thanks guys, appreciate the help. I'm out just now but will check the 12v VCC later today.

[sickboy]

Re: Sharp 32CHF5111K (TP.MS3463S.PB711) Fault

Hi again. Yep, there's 12v on pin1 on UB801. I also tried freezing the chip incase it helped show the chip as the culprit, no change though.

[R_J]

Re: Sharp 32CHF5111K (TP.MS3463S.PB711) Fault

Did you freeze the chip when the tv was unplugged? I thought you ment freezing the eeprom ic, this is the backlight driver, freezing it won't help

[sickboy]

Re: Sharp 32CHF5111K (TP.MS3463S.PB711) Fault

Did you freeze the chip when the tv was unplugged?

Yes, frozen with RS freezer spray, waited 30 seconds or so and powered on. Just the same symptoms though.

I looked through my spare boards (taken from TVs with broken screens) and tried one from a 40 inch version of the same model. Backlights came on but no image on screen - obviously due to the board being for a different screen. But at least it proves my backlights aren't the issue

[R_J]

Re: Sharp 32CHF5111K (TP.MS3463S.PB711) Fault

That UB801 is the backlight driver ic not the eeprom, so freezing it would not likely do anything.
Did you try freezing the spi/eeprom chip? I think this board uses a nand chip, mx30LF1G18IC, It might be available for this model

[sickboy]

Re: Sharp 32CHF5111K (TP.MS3463S.PB711) Fault

Ah ok lol. The nand must be on the underside of the board. Will check tomorrow. If it’s an spi 8 pin flash I can change it but a nand chip is beyond my soldering skills ☹️

[R_J]

Re: Sharp 32CHF5111K (TP.MS3463S.PB711) Fault

The spi would be located at UF1, it's not populated

[sickboy]

Re: Sharp 32CHF5111K (TP.MS3463S.PB711) Fault

Morning R.J., yeah it's a big nand chip on the underside of the board, I tried giving it a freeze as well but still no results.
I may just have to buy a replacement board for this TV I'm guessing, although I'm not sure if it's worth the cost given that it's a basic model with no smart functions.

[nomoresonys]

Re: Sharp 32CHF5111K (TP.MS3463S.PB711) Fault

Yes they want too much for this size screen, there's some with make offer, my offer would be half what they are asking at most: https://www.ebay.co.uk/sch/i.html?_f...F5111K&_sop=15

[sickboy]

Re: Sharp 32CHF5111K (TP.MS3463S.PB711) Fault

Yes they want too much for this size screen, there's some with make offer, my offer would be half what they are asking at most: https://www.ebay.co.uk/sch/i.html?_f...F5111K&_sop=15

Thanks. I managed to get one from EMOS (big UK supplier of used parts). It was advertised for £35 buy-it-now, but I sent an offer of £20 along with a note saying it's just a basic 32" TV and that would be my maximum offer. They accepted 20 mins later. That should be the problem solved, just a pity we weren't able to get down to component level repair on the original board.
Thanks for everyone's input though. Have a nice weekend guys.

[nomoresonys]

Re: Sharp 32CHF5111K (TP.MS3463S.PB711) Fault

Now that's more like it, good price.

[R_J]

Re: Sharp 32CHF5111K (TP.MS3463S.PB711) Fault

Morning R.J., yeah it's a big nand chip on the underside of the board, I tried giving it a freeze as well but still no results.
I may just have to buy a replacement board for this TV I'm guessing, although I'm not sure if it's worth the cost given that it's a basic model with no smart functions.

Was the tv unplugged when you tried spraying the ic? It needs to be unplugged, The ic is read when first plugged in. But that freezing trick usually only works with those 8 pin spi ic's and not the nand

You had 12v on UB801 pin1 , you could check pin8,that is the PMM pin that controls the brightness of the backlight