[SOLVED] TV repair - Identify component / diode (Hisense H65U7A)

[AntoineBurtz]

Hello EEVBlog members,

I am currently trying to repair my TV (Hisense H65U7A), after endless measurements I managed to determine the culprit.

This diode (?) had a 100-ohm short on one pin, I am currently looking for a replacement.



The measurements of the component are about 2.5mm (W) x 1mm (D) x 0.5mm (H). The diode has 10 pins, 5 on top and 5 at the bottom. I am not able to find a datasheet using the markings on the diode ('4264H').

The diode is part of the driver board of the TV that is directly connected to the panel with flex-cables. The driver/buffer board is manufactured by 'AUO' '65T50-S1E XR2 BD'.

This is the board in question:


Any hints towards a suitable replacement component would be very much appreciated.

[fzabkar]

Using D002 as a reference, it appears that there are 4 diodes, each connected to ground via pins 3 and 8. The top row of pins is connected to the bottom row. The anodes would be grounded.

If you fail to find a replacement common anode diode array, you could always install four discretes. You just need to determine the type of diode. Is it an ESD protection device?


Edit:

If the device is symmetrical, then why are the pin#1 locations reversed for D002 and D001?

Edit #2:

Could it be something like this?

https://electronics.stackexchange.com/questions/314114/connect-signals-to-n-c-pins-in-diode-array-for-esd-protection



Nexperia's IP4283CZ10-TT has a marking code of 4283:

https://assets.nexperia.com/documents/data-sheet/IP4283CZ10_SER.pdf


Edit #3:

Here is an equivalent part from Mouser:

https://www.mouser.es/new/stmicroelectronics/stm-hsp054-4n10-esd-protection-ic/
https://www.mouser.es/datasheet/2/389/hsp051-4n10-1621272.pdf

[AntoineBurtz]

Thank you for your efforts @fzabkar. Sadly I'm a electronics noob and can't provide you with much insight (software engineer here :p).

Pin 3 and 8 is indeed ground and the top row of pins is connected to the bottom, just like you assumed. In my case pin 2 had a 100-ohm short to ground. Upon removal of the diode in question, the short disappeared.

For your reference: The same diode on the other side of the panel reads 27V on pin 1, ~10V on Pin 2.

I will order the parts and report back after I soldered them with the results. Thank you very much again!

I attached some more pictures for documentation purposes.

Edit 1: You provided me with a 1.9mm x 1mm package diode. I have since corrected the measurements of the diode in my original post after using precise calipers, the actual dimensions are 2.5mm (W) x 1mm (D) x 0.5mm (H). I will look for a similar diode from ST in the right package size and provide the link here after I found it.

[fzabkar]

27V is much too high for those parts. The IC's breakdown voltage is 6V. We need to look again.

[AntoineBurtz]

I verified the readings for you on the other side of the panel, same diode, symmetrical board layout (mirrored on the other side of the panel). These are my findings:

- Pin 1, 2, 9, 10: Alternating between ~27V and -10.5V.
- Pin 3 and 8: GND
- Pin 4 and 7: Steady -10.5V
- Pin 5 and 6: Steady 27V

Again, the corrected diode dimensions are 2.5mm (W) x 1mm (D) x 0.5mm (H) (see my edit above).

[fzabkar]

Those diodes are not the correct parts. Sorry. :-(

[fzabkar]

I would measure the resistances between ground and the other pins, on the diode range and resistance ranges.

I would also measure the resistance between pin 1 and pin 2, both on the bad IC and the good one, in both directions.

This may help us to determine how the diodes are connected internally.

[AntoineBurtz]

I took some measurements on the functional diode:

It appears the pins are connected top to bottom and bottom to top. When I flip the leads in diode mode I get 0V drop both ways. Also the pairs are isolated from another and isolated from ground. Resistance mode shows O.L. when measuring any pin other then the pin right above/below.

The bad diode is sadly gone now, but it had a 100 ohm short to ground on pin 2.

Edit 1: I verified the readings again: The resistance between pins of different columns or other pins in the same row is ~50 MΩ. Any pin has a resistance to ground ~18 MΩ (other than the GND pins of course).

[AntoineBurtz]

I am not qualified enough to determine if this component works, but there is this Littlefuse diode with exactly the same dimensions and pinout:

https://www.mouser.de/ProductDetail/Littelfuse/SP1064E-04UTG?qs=aP1CjGhiNiHlyHz3guBN5g%3D%3D
https://www.mouser.de/datasheet/2/240/Littelfuse_TVS_Diode_Array_SP1064E_Datasheet-2509270.pdf

Maybe this would work?

[fzabkar]

Yes, that looks good. It even has a "64" in the part number. Maybe that's not a coincidence?

The breakdown voltages seem high for this application, though.

[TheMG]

Have you tried powering the TV with the component simply removed? Since it's a TVS diode array intended for ESD protection, the device should operate fine with it removed (without the protection offered by the diodes of course).

If the TV does not operate correctly with the shorted diode removed, then there is something else wrong in addition to the diode and further troubleshooting and repairs will be required.

[AntoineBurtz]

Have you tried powering the TV with the component simply removed? Since it's a TVS diode array intended for ESD protection, the device should operate fine with it removed (without the protection offered by the diodes of course).

If the TV does not operate correctly with the shorted diode removed, then there is something else wrong in addition to the diode and further troubleshooting and repairs will be required.

That is a good point. The diode seems to be in parallel, the PCB paths are still intact after desoldering the diode after all.

Before desoldering the diode, the short would result in a completely black picture. Sound and backlight would still work. Unplugging the faulty half of the panel (the half with the diode) would result in half a picture.

After desoldering the diode, the only part of the panel that is effected seems to be 1/12 of the picture: the part of the panel where the faulty diode was located and a flex-cable is going into the LED panel is completely black. (You can kind of see it in the attached picture). A total of 12 flex cables go from the driver/buffer board directly into the panel.

I'm starting to think that my panel is bad... Very disappointing to have this happen after 3 years of medium use. Should I give up on this one?

Edit 1: Oh my god.......... It was my laptop HDMI mirroring with a wrong aspect ratio making me think that that part of the panel is still faulty... After changing the HDMI mirroring settings on my notebook the panel seems to be fine!!! Winner winner chicken dinner!

[AntoineBurtz]

The new diode came in from Mouser. The TV worked fine the last week without the diode.

I soldered on the new diode, seems to be working fine for now. The part number is 'SP1064E-04UTG' (manufacturer is Littlefuse).

The footprint seems identical with the old part and it soldered on just fine. Please excuse the horrible image quality.

[onepostuser]

I made an account just to thank you.

My father was an electronist back in the day, repairing TVs, radios, VCRs, building satellite receivers from scraps etc.
These days he randomly bought a huge broken HISENSE TV (65") from someone for 25 Euro, in the hopes he can fix it, I guess for the old times nostalgia.
He can barely see nowadays (he is old), and the SMD components are minuscule.
He tinkered around for 2 days, got the TV to work with only half the screen showing as you did, and he narrowed it down to a small PCB.
I helped him out testing the small components with his old multimeter, one by one, each resistor, each capacitor... until only the 4264H IC remained untested. So I googled "4264H", and found this forum post.
Now even tho we dont own an SMD hot air gun, we managed to get the IC off of the board with a normal soldering iron, some thin copper wire and patience... aaand the TV works again!
Now I couldn't care less about the actual TV, but I wanna thank you from the bottom of my heart for how you made my father feel. He was so excited that he can still do it, he can still fix stuff! It brought me great joy to see him like that.

Thank you @AntoineBurtz.
Pictures attached.

[AntoineBurtz]

I am reading your post just now @onepostuser, its great that this post was helpful to you and your father Really put a smile on my face.

And btw the TV broke again yesterday, this time I had no video at all (no in-built menu, no HDMI) and just working backlight. I replaced the T-Con board with one I had laying around from my last repair and the TV is fixed again.

I didn't really have time to look closely what was wrong with the T-Con board, just wanted to give a last update here. The next time this TV breaks I am probably retiring it...