Unknown 6 pin burned component near power jack - Ultra Mobile PC - HTC Shift

[Haruki]

Hello, I bought this broken (with no power issue) old 2007 UMPC (HTC Shift X9500) and i would like to fix it.
It's a "little" device with Intel CPU and iGPU, full Windows Vista and also a custom Windows Mobile extra partition.

I found this 6 pin component burned, near the DC IN power connector. I think it's marked "83PAB".

On the PCB picture, 4 pins (marked "A" by me) are connected with the + side.
Pin marked "B" is connected with that green resistor, capacitors etc.
The one marked "C" is NOT connected with the others and is NOT ground.

I don't know if this is the only problem in the board and sadly the seller "don't known anything" about the device background.
Maybe they put the wrong power supply ? This device works with 12v (and not 19v like a normal notebook).

Someone can help me to identify this component, what it does and if the UMPC could work without it?

I will add more pics if needed, thanks for the help!

[PA0PBZ]

Must be a mosfet of some sort, compare the pinout: https://nl.mouser.com/datasheet/2/196/Infineon_BSD316SN_DS_v02_04_en-1226391.pdf

I guess it should be safe to connect the A and B connections and see what happens.

[Haruki]

Thanks. It's similar i think...pin 1 2 5 6 are linked like in the pcb. Sadly i can't test the original component (it's split in half now...it was really burned) and the mark on it is useless .

There is some other test that i can do before bridge the A - B connections ? Just to be sure of not doing more damage to the board when i will power it...

[PA0PBZ]

Just make sure that there is no short so use a current limited 12V power supply, start at like 100mA and if the supply does not go into protection increase the current. Alternatively, measure the resistance between "B" and ground, if it's close to zero ohms there might be a problem further down.

[Haruki]

The resistance between "B" and ground is in MΩ. Between + and ground in kΩ. So no one of the pins are close to zero ohms to ground.
I also tested the capacitors and they are NOT shorted.

[PA0PBZ]

So go for it, make the connection between A and B and apply 12V, or just apply 12V to B.

[DavidAlfa]

Might be the OB2283 PWM controller.
Edit: No way, checking the pcb layout, definitely a MOSFET.

[Haruki]

Are we sure that nothing will explode with that bad bridge? xD

[DavidAlfa]

Edit: I missread some details you wrote. Yeah it seems good to go!
But before:
Measure resistance in all other similar step-down circuits (Should be plenty of them, for each voltage), between the coil and gnd.
Some output cap could be shorted, I've seen this a lot in the 3.3V aux circuit (It's always in even when the laptop is off).
Low resistance readings (Even 10 Ohms) can be normal as some of these circuits use a lot of power.


When ON, measure voltage at C pad (gate). Unless wrong, with that footprint and routing only a N-ch fet will work there.
So C must have 8-12V more than Vin, expecting 20-24V.

I fixed several old HPs with a similar issue.
They had a charge pump for this, went bad, the output voltage (Applied to the mosfet gate) became much lower, so the fet didn't conduct well, overheated and burned.


Please make a picture showing these parts numbers:

[mikerj]

Are we sure that nothing will explode with that bad bridge? xD

If that MOSFET is the switching element in a switched mode regulator than something bad is likely to happen.

[DavidAlfa]

But it doesn't seem so, look at the first picture of the thread.
Looks like a switch for the external power, powering all the internal regulators.

[Haruki]

I already connected the power supply before the different opinion was wrote...but i did NOT switch on the device.

I just misured the voltage in that area. Before, with the bad component still soldered, the voltage in the near coil was only 2.5v. Same voltage in the + pin of the battery connector on the board.
With the component removed (and that bad bad bridge), the voltage is now 12v where before was 2.5v. Again all this with the board OFF (but the power plug in).

The original power supply is 12v 3A.
The battery voltage is 7.4 - 8.4v.
I can't try to power the device only with the battery because is full discharged...

I know that replace the component is the best solution...and is what i asked from the start...but the marked code was useless so i didn't know what to do...
When i bought this device i hoped was just the power jack / fuse or capacitors / ic that usually have all the information marked on the component xD.
But this time was something "different" and i didn't find any information with the code printed on it... But i found this forum where others asked for similar thing and i tried also! ^^"

@DavidAlfa I read now your edited post...one of that chip is the battery management ic. I will add more photos, sure. Thanks!

edit: done! Say me if you need more.

edit2: ok with a bit of courage i partially reassembled it... tried to power on...and it's alive!!!
          So what to do now? It can really works without that component or will explode later? xD

[Haruki]

Hello again...so just to give a conclusion to this topic, i did some test with the HTC Shift and nothing exploded or burned 🤣.

I can't access the original Windows Vista HDD partition sadly (it''s now a RAW partition) and the hard disk is read like "DOCHIBA" instead of "TOSHIBA" on the bios, really odd... 

Anyway i tried an old win10 iso started from the usb pendrive. It's slow but at least all seems to work (or almost all, some driver missed).

I will try to put an adaptor ZIF - mSata to replace the hdd with an SSD, installing w7 or some light linux distro, just for fun.
I know that the hardware was "poor" also for the 2007 and is not much usable now... :'(

Some photos here!

I want to thanks again all for the help, i will write again in this forum if i will find others "unmarked" component in future repairs. Bye!

[DavidAlfa]

DOCHIBA??   you made made day!

I recalled a friend's PC in the 2000s, 60GB crap with Windows Millenium, can't remember how he managed to f*** it up but he managed to get a 2TB partition.
That's the friend for I still remember the win98se key, I swear I'm not facking it, I think it was MP7TK-KPT9F-DJFH9D-B3828-HFH9D, maybe in wrong order 
He literally needed new OS every 15 days!
I learned about disk imaging (Norton Ghost) when it was too late, the key is already engraved in my soul and I'll die with it.
I remember giving him the image in a cd.... "When it breaks, just put it in and click restore. Fck off lol"

[Haruki]

I don't know what they did before with this device, but yes...the hdd show as one RAW partition and real "DOCHIBA" name on bios and also on CrystalDiskInfo, AIDA64 etc....
Also the model - firmware and serial number are not right 🤣.

I would like to see the original Vista OS (and the old data) but sadly can't. 🤣
The windows mobile part is working fine (stored in an internal memory i think)...and is clean with no data at all, so maybe a bad / wrong reset of the device before was sold and killed later from someone else with a wrong power supply?
The seller only information was "it's not turning on idk it wasn't mine"  .

Or the hdd is just dead (there is one "Current Pending Sector"). Still i will just replace it with an adaptor + modern ssd, the most important thing for me is that now it's turning on and works fine!

See photo and screen (in italian sorry!) and thanks again!   

[Daixiwen]

So what to do now? It can really works without that component or will explode later? xD

The MOSfet was probably used to protect the electronics against reverse polarity, and maybe overvoltage. You can use the machine fine without it, but if you ever connect it to the wrong power supply it will destroy a lot more on the board.
Be also very careful with the battery, it could have been damaged if it was overdischarged and kept that way for a long time. If you ever see it swell, stop using it at once.

[Haruki]

Hello again xD.

It could be that someone in the past used the wrong power supply. I think this also.
I have the original power supply now so no poblem. The UMPC is working fine (except for the deadly hdd).

For the battery yes....there is green stuff and a broken connection so the battery is gone. I only saved the original battery circuit (photo n3).

2x flat 3.7v, so maybe i can use two new of them. I also wrote how the originals was connected ( VG B2- | VH B2+ B1- | VP B1+ ).

Anyway for now i'm just waiting for the ide/zif - msata board adaptor so i can use the ssd and do more test with windows or linux.
Idk if it can be really used for something, but still is an old nice device to have, like all the others UMPC (until now i also found for cheap the samsung q1 and a "more new" Viliv N5). 

[hooddy]

Hi there

Can someone tell me which is correct part number or manufacturer and description for HTC Shift power switch please? I have broke this plastic stick and need to replace it. It is easily open with needle and replace inner plastic contact plate.