Nvidia Shield TV, No Power. i've found the culprit. please help ID this chip.

[reddemonic]

the markings on this chip is M055 could be Mo55. i think its a MOSFET.

i've checked against a good known working board.

Good chip
-----------------------
pin 1,2,3,4,5 = 18.9v
pin 6 is ground = 0v


Bad chip
-----------------------
Ground pin is giving out 17.5v -- should be zero
pin 1,2,4,5 = 2.8v
pin 3 = 18.9v



can anyone help me ID this chip please?
can i use alternative like these?

https://cdn.badcaps-static.com/pdfs/...a9b26f9a29.pdf
https://cdn.badcaps-static.com/pdfs/...54727f80c5.pdf

[budm]

Re: Nvidia Shield TV, No Power. i've found the culprit. please help ID this chip.

To have that much Voltage on the GND pin it means that the GND is not having connection to circuit GND, so you need to check the resistance between GND pin and the circuit GND, it should show <1 Ohm if it is an actual circuit GND.
So are you sure that pin is connected GND, and it is MOSFET for sure?
Pin 3 is G (GATE), not GND per your spec of the MOSFET so I doubt that it is connected to circuit GND.
BTW, I doubt that the sub you link to is correct becuase pin 1, 2, 5, and 6 are directly connected together for the Drain (D) so your reading as shown in your post 1 does not match the MOSFET of the link:

Good chip
-----------------------
pin 1, 2,3,4, 5 = 18.9v
pin 6 is ground = 0v

Also, the pin you named GND in the picture is pin 3, not 6.

[reddemonic]

Re: Nvidia Shield TV, No Power. i've found the culprit. please help ID this chip.

i dont know what it is. as i cant find a data sheet on this m055.

[budm]

Re: Nvidia Shield TV, No Power. i've found the culprit. please help ID this chip.

Can we see the whole board so we can see what we are dealing with? Also you have good board that you use for the comparison reading?

[reddemonic]

Re: Nvidia Shield TV, No Power. i've found the culprit. please help ID this chip.

ah i did the measurement long ago. i'll restart everything. i think i made a mistake pin 6 being ground. i'll have to buy working unit to test again. sorry about this.

[Longbow]

Re: Nvidia Shield TV, No Power. i've found the culprit. please help ID this chip.

Well, great that you made a chart of the voltages. Your conclusion that the chip is bad is incorrect. There is no way that the "ground" part of that circuit could be raised to 18 volts without a pcb break. I'm assuming that your "ground" or black mm probe is placed at the same spot in both cases? If you turn off the set and measure resistance between the circuit "ground" and the Source of the FET, I think you will find it to be open. Possibly the solder pad itself has covertly cracked around the FET pin, or somewhere nearby the pcb has developed a crack. Resistance checks will locate the fault in no time.

[stj]

Re: Nvidia Shield TV, No Power. i've found the culprit. please help ID this chip.

M055 comes up as a Ricoh 5.5v regulator.

[cpt.charlie]

Re: Nvidia Shield TV, No Power. i've found the culprit. please help ID this chip.

Is this chip located near big caps and coils? It could be a power supply IC.

[kc8adu]

Re: Nvidia Shield TV, No Power. i've found the culprit. please help ID this chip.

thats a mosfet switch.
it is turned off by the high gate either because it is shot or its control circuit is turning it off.

[gwene]

Re: Nvidia Shield TV, No Power. i've found the culprit. please help ID this chip.

the markings on this chip is M055 could be Mo55. i think its a MOSFET.

i've checked against a good known working board.

Good chip
-----------------------
pin 1,2,3,4,5 = 18.9v
pin 6 is ground = 0v


Bad chip
-----------------------
Ground pin is giving out 17.5v -- should be zero
pin 1,2,4,5 = 2.8v
pin 3 = 18.9v



can anyone help me ID this chip please?
can i use alternative like these?

https://cdn.badcaps-static.com/pdfs/...a9b26f9a29.pdf
https://cdn.badcaps-static.com/pdfs/...54727f80c5.pdf

Did you manage to repair and what was damaged?

[Warpcoil]

Re: Nvidia Shield TV, No Power. i've found the culprit. please help ID this chip.

I too would like to know if you got this repaired..?

[illiac4]

Re: Nvidia Shield TV, No Power. i've found the culprit. please help ID this chip.

Hi. Did someone managed to identified the chip? It seems that this si also a common problem on Nvidia Shield 2017. I assume that this one is the cause for no power.

[Chunny1980]

Re: Nvidia Shield TV, No Power. i've found the culprit. please help ID this chip.

Hi, i've got a problem with a 2017 shield tv. it's not turning on at all, no green light. i've tested the power supply and the board is receiving 19v on the mains input so i assume the plug is working fine.
Also there is a very faint humming sound coming from the board when it's plugged in.

Is there anyone here who has managed to diagnose and fix a similar problem with this model that would be able to give me an idea of where to go next?.

I'm a novice at this sort of stuff but i'm very keen to learn.

[gerry1980]

Re: Nvidia Shield TV, No Power. i've found the culprit. please help ID this chip.

Hello!
I have the same problem on a Shield TV 2019...
It seems not an easy task to identify this chip.
On some boards it is labeld as Q16.
My defekt chip is pictured here and has the following description on it.
D5CL 14

So we have...
M055, 1052U and D5CL 14
This bastard seems to have multiple identities ;-)

Hope someone can identify this culprit...
I'm running out of options. :-)

[lotas]

Re: Nvidia Shield TV, No Power. i've found the culprit. please help ID this chip.

1052U - 105xx - APM2605C

D5CL - D5xx - AO6405

[gerry1980]

Re: Nvidia Shield TV, No Power. i've found the culprit. please help ID this chip.

1052U - 105xx - APM2605C

D5CL - D5xx - AO6405

Thank you very much !!!
Ordered some of those. I will report the result of my repair attempt.

kind regards
Gerry

[gerry1980]

Re: Nvidia Shield TV, No Power. i've found the culprit. please help ID this chip.

Hello again,
I'm back with some results and my learnings, which I will share with you.

The mosfet was indeed damaged,
but it was damaged because of another problem in the circuit.
The real culprit was a shorted ceramic capacitor.

I was able to find it with voltage injection.
1V, 2A. Black wire to GND,
red wire to the drain of the MosFet (soldered a little wire to it).

Then I was able to find the hot capacitor with alcohol, removed it and the Shield was alive again, but not totally fixed.

The mosfet is like a switch to interrupt the powersupply if something in the circuit is shorted. So the mosfet is not conductive if the powercontrolchip recognizes something is wrong. But my mosfet was also damaged because it was conductive all the time.

The dogdy way would be to let the damaged/bridged mosfet, because Shield was working. But the protection mechanism would be disabled. So I replaced the mosfet also.

And I learned something more from Sorins youtube channel.
The mosfet in this case acts like a switch.
So the only important things are:
1. Same type, in this case a P-Channel.
2. Manage the switched power..., in this case 19V, 3A.
3. Same layout, pinout.

With this information it is easy to find a fitting mosfet.

Hope this is helpful for someone !

kind regards,
Gerry

[duder]

I realize this is an old thread. I was hoping you could remember approximately where you found your shorted capacitor on this board. I have a short to ground on the drain of fet. It is taking a maximum of 3a at 1 volt, but I cannot find anything hot. Warm, but not hot. I once found a shorted cap on an xbox board with the temperature probe on a cheap multi-meter that I could not find with my finger or alcohol. Thanks in advance

[soler88]

Re: Nvidia Shield TV, No Power. i've found the culprit. please help ID this chip.

Hello again,
I'm back with some results and my learnings, which I will share with you.

The mosfet was indeed damaged,
but it was damaged because of another problem in the circuit.
The real culprit was a shorted ceramic capacitor.

I was able to find it with voltage injection.
1V, 2A. Black wire to GND,
red wire to the drain of the MosFet (soldered a little wire to it).

Then I was able to find the hot capacitor with alcohol, removed it and the Shield was alive again, but not totally fixed.

The mosfet is like a switch to interrupt the powersupply if something in the circuit is shorted. So the mosfet is not conductive if the powercontrolchip recognizes something is wrong. But my mosfet was also damaged because it was conductive all the time.

The dogdy way would be to let the damaged/bridged mosfet, because Shield was working. But the protection mechanism would be disabled. So I replaced the mosfet also.

And I learned something more from Sorins youtube channel.
The mosfet in this case acts like a switch.
So the only important things are:
1. Same type, in this case a P-Channel.
2. Manage the switched power..., in this case 19V, 3A.
3. Same layout, pinout.

With this information it is easy to find a fitting mosfet.

Hope this is helpful for someone !

kind regards,
Gerry

Gerry,

Just wanted to thank you for sharing your findings. Following your steps, I found the shorted cap. My shield is alive after collecting dust for the last 2 years!
Did you replace the cap as just leave it off?

[soler88]

I realize this is an old thread. I was hoping you could remember approximately where you found your shorted capacitor on this board. I have a short to ground on the drain of fet. It is taking a maximum of 3a at 1 volt, but I cannot find anything hot. Warm, but not hot. I once found a shorted cap on an xbox board with the temperature probe on a cheap multi-meter that I could not find with my finger or alcohol. Thanks in advance

Here's the cap that was shorted on mine.
Hope it helps