HiSense 65H6510G no boot

[lotas]

Re: HiSense 65H6510G no boot

eMMC is dead.

[howardc64]

Re: HiSense 65H6510G no boot

questioners.
1- when you test it the R & B LED and they light on with diode mode... when you change the probe in opposite way. did you have any read value on yours DMM?

2 did the 5 STBY drop down while 3.3V failed ?

in normal operation. when we press power the R LED will blink once then B then R then B then R them B remain on. so you wrote before the R LED will blink once and went out correct ?

Thanks for the suggestion. Here are the answers and also update after UART output

• Red and Blue LED both reads OL on DMM in reverse polarity.
  
• 3.3V STBY didn't drop. It stays 3.3V at the voltage regulator. Only 3.3V signal to the SOC drops to 0v when I press power button.
  
• On this board, I'm not sure how blue LED can light up since its cathode is not connected to anything (I will check more carefully to confirm)

=====

Now for the UART output.

Building UART to 3.5mm service port cable

Leaving notes here for others in the future.

Here is a diagram. No need to use DB9 connector if you have common cheap USB<->UART dongle (must be <= 3.3v, mine was 2.5v on TX/RX)

Sleeve = Ground, Ring = TX, Tip = RX
Set to 115200 baud per post #22. 8 bit data, stop bit 1, parity none, handshake none.
Need to push the 3.5mm jack in firmly until it clicks. Had mine loose for awhile and was getting mixed garbage.

I used terminal ( link ) Couldn't get putty to work.



UART output

UART shows BIST ok (Built-In Self Test) Repeated eMMC CMD2 error and then reboots and repeat.

----

AC_ON
MIU0_DQS-OK
BIST0-OK
02-2L-SM-01-20180913
eMMC Err:CMD0002 0027eMMC Err:CMD0002 0027eMMC Err:CMD0002 0027eMMC Err:CMD0002 0027eMMC Err:CMD0002 0027UART_115200

AC_ON
MIU0_DQS-OK
BIST0-OK
02-2L-SM-01-20180913
eMMC Err:CMD0002 0027eMMC Err:CMD0002 0027eMMC Err:CMD0002 0027eMMC Err:CMD0002 0027eMMC Err:CMD0002 0027UART_115200

AC_ON
MIU0_DQS-OK
BIST0-OK
02-2L-SM-01-20180913
eMMC Err:CMD0002 0027eMMC Err:CMD0002 0027eMMC Err:CMD0002 0027eMMC Err:CMD0002 0027eMMC Err:CMD0002 0027UART_115200

----

eMMC is Hynix H26M41204HPR running eMMC 5.1 spec ( link )
eMMC 5.1 spec uses JESD84-B51A boot mode (an old JEDEC spec so basically backward compatible) boot mode spec indicate CMD2 is basically "Request eMMC chip for Chip ID" and UART log shows repeated failure and reboots.

So basically can't get any data out of eMMC. Will debug around this area to see if can find any failure cause. boot code spec does show CMD0 and CMD1 is executed before CMD2 in A.6.1 Low-voltage power-up. Also CMD1 returns data so the basic eMMC command and data IO bus maybe working. Seems like something happened to the eMMC.

[Diah]

Re: HiSense 65H6510G no boot

questioners.
1- when you test it the R & B LED and they light on with diode mode... when you change the probe in opposite way. did you have any read value on yours DMM?

2 did the 5 STBY drop down while 3.3V failed ?

in normal operation. when we press power the R LED will blink once then B then R then B then R them B remain on. so you wrote before the R LED will blink once and went out correct ?

[howardc64]

Re: HiSense 65H6510G no boot

can you show me the IR section & the LED indicator build on it... Hisense as i know there are 2 one Red and other blue LED or one RGB. be sure they are fine and not shorted to kill the 3.3 rail..

Thanks, here are the checks

LED circuit

• There are 2 LEDs (Red, Blue) in a single LED package. Both LEDs light up in diode mode with probe on LED anode/cathode
  
• Blue LED cathode is NC (Not Connected) anode connected to ground (I guess doesn't matter if cathode is NC?) Since both LED is in single package, blue LED is present because in same package but unconnected.
  
• Red LED light up in diode mode probing from disconnected XP4 (pin2 GND, pin3 LED1). XP4 is small IR/LED/KEY board connector to main board.
  
• Red LED doesn't light up in diode mode when XP4 is connected. Presumably main board LED1 circuit drained the + probe from multimeter in diode mode?

Power Button

• line to SOC reads 3.3v when power button not pressed. Reads 0v when pressed.

Board pics



Seems both circuits are behaving correctly...

[Diah]

Re: HiSense 65H6510G no boot

can you show me the IR section & the LED indicator build on it... Hisense as i know there are 2 one Red and other blue LED or one RGB. be sure they are fine and not shorted to kill the 3.3 rail..

[howardc64]

Re: HiSense 65H6510G no boot

Still waiting on the USB<->UART dongle and will provide update after.

Debugged the main-tcon board power rails. CPU is either dead or lost with corrupted firmware/bootcode.

Standby Light off

Standby light circuit gets 3.3v signal from CPU but signal is active low. Therefore, Standby light stays off. CPU never turns it on. When first plug in AC, likely flashed as 5V rail was stable before CPU voltage so circuit momentarily had 0v until SOC powered up enough to assert its active low signals to 3.3v (probably GPIOs) Standby light circuit attached (Same as 2018 main board service manual in post #1 but all NC component removed which was also NC on my board)



LCD PMIC

This region was dead without voltage. Traced circuit to how to turn on (CPU suppose to turn it on) Manually jumped the trigger to turn on and all LCD PMIC voltages are valid (VGH, VGL etc)



Other Power Rails Powered Up

2x 1v SOC rails. 2018 board with same SOC shows 1A rail for CPU power. 4A rail for CPU core (probably means SOC core like GPU or video with 3.5A!), Core's DDR and HDMI digital logic) A bunch of caps on these rails does show ~200ohm to ground but they don't heat up (SOC does since nearby) and DC voltages are all correct without any AC component (all stable). Probably correct?
eMMC 1.8v 3.3v
DDR3 1.5v
SOC 1v
5v and 3.3v throughout the board
12v from PSU obviously to generate all above voltages.

====

Anyway, since SOC's CPU never turns on standby light and LCD PMIC section, its likely CPU is dead or lost due to corrupted boot code. Unfortunately, these HiSense main boards are basically unavailable and ~$100+ when it is so I'll keep going to see if can revive it. But it doesn't look good. HiSense support currently seems broken even on providing USB firmware upgrades much less bootcode +flash tools. Probably need to extra firmware from good TV in case of corrupt firmware revivals.

Will report back after USB<->UART dongle arrival.

[howardc64]

Re: HiSense 65H6510G no boot

You just need to find Rx, Tx, GND, 3.3v on the board, you don't need them on the uart-usb adapter itself (you just need the signal lines to be at 3.3v). Connection is like this:
Rx - Tx
Tx - Rx
GND-GND.

yes they both will work fine with speed setting 115200 only TX and RX GND connect and use Putty... when you plug the tv In power keep pressing inter on PC until you see MSD XXX# xxx depend on soc No.

if you get this just send "" mmc part "" with out ""
if the emmc / nand in tact will report all partition

Thanks! Will gather HW/SW parts and report back... Lets see if HiSense will handout bootloader + flashing software haha.

[Diah]

Re: HiSense 65H6510G no boot

yes they both will work fine with speed setting 115200 only TX and RX GND connect and use Putty... when you plug the tv In power keep pressing inter on PC until you see MSD XXX# xxx depend on soc No.

if you get this just send "" mmc part "" with out ""
if the emmc / nand in tact will report all partition

[lotas]

Re: HiSense 65H6510G no boot

You just need to find Rx, Tx, GND, 3.3v on the board, you don’t need them on the uart-usb adapter itself (you just need the signal lines to be at 3.3v). Connection is like this:
Rx - Tx
Tx - Rx
GND-GND.

[howardc64]

Re: HiSense 65H6510G no boot

Anyone knows necessary spec for the HW UART connection to this TV?

Service Manual for 2018 HiSense (link in post #1, this TV is 2020 but use same main SOC) shows a HiSense serial board RSAG7.820.2335T with USB to PC and DB9->3.5mm jack to service port.

Same 2018 service manual shows UART circuit diagram which connects directly to main SOC (probably 3.3v GPIO?). I'm guessing the proper signaling probably requires 3.3v RX/TX. I measured the service port directly and see 3.3v



Finally, has anyone used a cheap USB<->Serial TTL dongle based on FT232RL or CH340G to connect to UART on these HiSense TV's service ports? Both of these have changeable RX/TX voltage from 5 to 3.3v.

Just want to make sure I gather the correct USB to UART HW.

Thanks

[howardc64]

Re: HiSense 65H6510G no boot

since its Android. there are no Mboot... will be bootloader... and if the bootloader not in tact then no more reboot or try to reboot.

Thanks, will look for bootloader.

suggested in your case remove any load from MB... BT or WIFI.... speaker ... BGA at the parts i mentioned before cause this too.... at the end all repair level just replace boards. if there are no Oscilloscope in hand.

Tried removing all connectors (panel, wifi, speaker, with and without IR+power button) and unfortunately no sign of booting (no SPDIF, CPU enabled USB port power)

And yes, without scope, hard to make much progress other than board swap. Given the availability and cost of the boards > $100, most owners encountering are just trashing the TVs

Try to find the TX and RX points on the board, connect the UART to USB adapter to them, run the terminal program and look at the terminal boot log, and you will see where the problem is. (The main thing is that UART is not disabled in the firmware itself).

Yes, TV has 3.5mm audio jack for service port that is UART. Searching for my USB UART dongle or order one or find old DB9 computer and build a cable. Then I'll have more insight on CPU activity/any logs.

Since there are so many firmware failures on these HiSense Android TVs, am motivated to see if can succeed firmware reinstall to publish procedure and help save more of these hisense TVs

[lotas]

Re: HiSense 65H6510G no boot

Try to find the TX and RX points on the board, connect the UART to USB adapter to them, run the terminal program and look at the terminal boot log, and you will see where the problem is. (The main thing is that UART is not disabled in the firmware itself).

[Diah]

Re: HiSense 65H6510G no boot

since its Android. there are no Mboot... will be bootloader... and if the bootloader not in tact then no more reboot or try to reboot.

suggested in your case remove any load from MB... BT or WIFI.... speaker ... BGA at the parts i mentioned before cause this too.... at the end all repair level just replace boards. if there are no Oscilloscope in hand.

[howardc64]

Re: HiSense 65H6510G no boot

i need to correct my post #8
i just learned yours TV Android. so the PWB will be in high always for warm start 12 / 20 V.

Yes its Android TV. Can you explain what "PWB will be in high mean"? Does it mean backlight voltage will not be final?

FYI, I also learned 20V = VCC_A for the audio amp from the service manual schematic.

so the boot loop caused by MB either emmc or CPU / RAM BGA or could be Firmware too since its android... try to contact Hisense and ask them for Firmware if you couldnt find in net

I guess you are thinking the periodic ~30s PWB squeal / brief voltage drop is main board boot loop. Checked all signal from main->PWB and all are steady when this occurs

STB = 3.43v
BSW = 0.084v (I think this is backlight switch)
BRI = 0.084v (probably PWM dimming according to service manual schematic)
ANA = 0v (PWM2 in service manual schematic)

From PWB

VCC_A = 20v will drop momentarily when this occurs
12V = 12.5 steady when this occurs

Possible ~30s PWB squeal / voltage drop is caused by PWB? This does not occur with main disconnected but all the voltages aren't stable or don't look correct when main is disconnected anyways.

could be Firmware too since its android... try to contact Hisense and ask them for Firmware if you couldnt find in net

Contacted HiSense. My understanding from service manual is to first get mboot working to enable USB flash upgrade.

MSTV_Tool.exe and ID password to complete "deciphering" which seems to be "unlock ability to flashing eMMC"
ISP_Tool to flash mboot to eMMC
Correct TV bin file for USB upgrading

Seems like many firmware corruptions just require USB upgrade so mboot remains intact and main gets far enough to light up the screen with logo. If this one is firmware failure, then it would have also corrupted mboot.

Check all solder joints with microscope, and give m the wiggle test which works good to find one that looks good but isn't.

Will do, hard to untangle which is bad (PWB or main) so will proceed both for now.

[nomoresonys]

Re: HiSense 65H6510G no boot

Check all solder joints with microscope, and give m the wiggle test which works good to find one that looks good but isn't.

[Diah]

Re: HiSense 65H6510G no boot

i need to correct my post #8
i just learned yours TV Android. so the PWB will be in high always for warm start 12 / 20 V.
so the boot loop caused by MB either emmc or CPU / RAM BGA or could be Firmware too since its android... try to contact Hisense and ask them for Firmware if you couldnt find in net

[howardc64]

Re: HiSense 65H6510G no boot

UPDATE

The PSU does make a faint noise differently with main connected and disconnected. Furthermore, one periodic noise correlates with voltage drops.

Main Connected

- Every ~30s will hear a faint 1/2s squeal sound near the big transformer (haven't isolate it exactly where from) when this sound occurs, all DC voltages will drop momentarily. 195v will drop about 10v on digital volt meter. Even main side's 1v CPU supply voltage will drop a tiny amount (few 100th of a volt on the meter)

Main disconnected

- No periodic squeal but a faint clicking sound that speeds up after plugging in AC which seem to gradually become steady clicking frequency.

So I guess PSU could still be suspect as without a scope, can't see how clean the DC voltages are going to main.

[howardc64]

Re: HiSense 65H6510G no boot

I hate situations like this. It's the way of the world sadly.
Can you scope something on the ARM chip to at least see if it's alive (clock etc)?
Wish you luck.

Unfortunately no scope or logic analyzer. That would be helpful of course. But I suppose seeing heat signature in one spot in the SOC and one side of eMMC indicate there is clock (or a short of course but my probe found none)

And been fixing lots of easy fixes (change LED backlight, blown PSU caps, shorted panel edge driver caps and flex etc) Finally hit a couple of hard ones like this haha.

Did you say earlier the 12v rail was at 9.4v?
Why is the 12v at 9.4v?

Yes, PSU has a couple of mysteries and I know nothing about power electronics

Just doubled checked and it will read 12.5v (solid and steady) when main is connected. When main is not connected, Connecting AC and multimeter will read 9.5-12+v (depending on how long leave AC disconnected, seems to get higher voltage if disconnected longer) and quickly drop to settle in at 9.4v. Traced it back to the 2 rectifier that generates 20v and 12v. Will read 12v at rectifier output when main disconnected (can no load cause this?) Here is pic and data sheet for the 6 cold side rectifiers



https://datasheetspdf.com/pdf/108335.../2CZ20100A9S/1
https://datasheetspdf.com/pdf/100455...tor/10F40HF3/1

Also many TV PSU will light up LEDs when main is disconnected. I guess must be default behavior without main. Don't have a reference on this HiSense. Great if someone can chime in if HiSense (ideally this model) does the same.

[dan8139]

Re: HiSense 65H6510G no boot

I hate situations like this. It's the way of the world sadly.
Can you scope something on the ARM chip to at least see if it's alive (clock etc)?
Wish you luck.
Did you say earlier the 12v rail was at 9.4v?
Why is the 12v at 9.4v?

[howardc64]

Re: HiSense 65H6510G no boot

if you are sure MB disconnected and this is the value u have,,, then you have one Optokoppler between primary and secondary PWB defect

I only see 1 optocoupler on bottom of PSU (right of center). The diode side measures good (1325 in forward bias, 0 in reverse ) Don't know how to check emitter collector side in circuit.

Maybe try the powerboard as stand alone and see if you get steady voltages and backlights on.

PSU doesn't light up backlight with main disconnected. Anyway, there is clear evidence main is dead. Here is latest summary

I believe the boot sequence is as follows

- PSU generate 12v to main and 20v (not sure what this is for, maybe tcon or audio amp? I have seen LG tcon's PMIC generate 20v+ VGH from 12v)
- If main boots properly, it will turn on standby light and power on IR. If TV is requested to power on, main will tell PSU to turn on backlight along with supplying analog or PWM dimming signals. PSU on this board shows ANA signal at a minimum (I've seen ANA and PWM dimming on a 55 Samsung but not sure HiSense have both)
- BSW (Backlight Switch?) between PSU and main is likely the signal main uses to tell PSU to turn on backlight. Goes to about 0.8v when AC is plugged in. I jumped this line with 3.3v standby (generated by main's DCDC power tree) and saw backlight flash on briefly. I'm guessing probably need to supply proper ANA signal (maybe jump 3.3v also) to keep it staying on.

- Main's DCDC power rails use PSU's 12v to converts to all the necessary voltages to drive its components starting with the computing system (CPU=1v, DDR3=1.5v, eMMC=3.3v and 1.8v) just to be able to boot the computer. Other voltages like 5v exist for USB, IR, wifi, etc
-All of the main's computing system voltages are present checking around SOC/DDR3/eMMC. One of the 2 USB port has no 5V. Circuit trace (service manual has the circuit diagram) shows its enabled by the CPU so CPU didn't get that far.
- FLIR image of main shows one region of SOC and one side of eMMC warms up on plugging in AC. This likely shows everything is configured to start reading boot/system code from eMMC. The correct boot sequence on AC plug in would be to enable IR and turn on standby light at a minimum. But lacking standby light, 2nd USB port power, no SPDIF light etc... means SOC didn't get very far.

So main is dead and I suspect it is likely firmware. Main boards for this TV (3 years old) is out of stock everywhere @ $100. Many complaints of slow smarttv software and bricking from updating the TV. Anyhow, Hisense doesn't even provide USB recovery firmware without request. Not sure can get PC flashed tools and firmware.

So to summarize, main has the 12v source from PSU and DCDC generates all voltages for the SOC, DDR3, eMMC but no evidence its booting very far. Don't think I want to invest $100+ on a replacement main so will see if can gather enough SOC tools to see if can at least get a terminal prompt over the service port (3.5mm jack for serial UART signal)