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Yes ! it was a bulging cap on the LG tv PS ...
https://archive.org/details/manuals
So here's one of todays challenges, it's an Asus Zenbook which is a tablet PC running Win 10 with a magnetic clip in keyboard. This is in bad condition, the screen is cracked all over and the micro USB port used for charging has been pulled on the board. The cost of a new screen and repairing the board makes it BER but the customer wants the data. How do you get the data of a tablet which you can't turn on. Now normally I would remove the shattered digitizier and LCD to get at the board, fit a new socket and than a new screen but they won't pay for that .. they just want the data. i can't tether it to a PC, the usb port is gone.
Now if you find yourself in a similar position and these micro USB ported tablets always break here's what I did which was quick and easy
I cut a hole directly above the micro USB port. With that out of the way I attached 2 wires, one for 5V and one for ground. If your not sure which one is ground buzz the end track that's shorted to the chassis pad, that's ground and any connection to that will do. The pad the other other side on the end is 5V. Then cut a micro USB cable in half and identify 5V and ground. One this cable it's red and black but never trust the colours, always measure.
Now that alone will generally very slowly charge at around 400mA as the charger can't identify the device and what current to put out as there's no connection to the data pins and their tie resistors. So fooling the charger with some external resistors to bias the D1 and D2 will allow more charge. So this doesn't look pretty but it's up and running and I'm copying their data to the SD card in the slot. Job done, very much billable for me and very simple.
Amazon and Ebay are awash with fakes and cheap Chinese copies, I tend to either buy the genuine article in used condition or buy a good after market model like the LL Power range from PSA parts
Havent taken it apart again to see if i've knocked the wiresloose again after resoldering or what but it wouldnt surprise me as i am shite at soldering.
So little favour for a friend today who brought a 9V adapter for his pedal and surprise it doesn't work as like 99% of these things it's centre pin is wired positive.
So here's a quick hack to change that around while keeping things neat.
Cut the wire so both positives are long and both negatives are short. Cut a piece of heatshrink and to make things easier make 2 lumps of bluetack.
Slide the heatshrink over one end length of wire first, then position wires on bluetack .... the fact you cut both positive wires long on each bit of cable now means the polarity will be swapped over when you join them.
A neat joint is a piece of cake when sat on the bluetack
Then slide your heatshrink over the joint and then you have a Boss type adapter 9V centre neg with no big joined lump in the cable and no chance of the wires shorting out because their joins are spaced apart.
Why? You remove material from the bottom, so the eyes won't matter.
So here's a great little cheap tool to help diagnose whether the problem of a typical tablet being dead is the charging port or the battery or both. This cost about £4 and can save you so much time. Plug in inline to the USB charger and it will give you the voltage and the current being drawn. So before you plug the cable into the tablet you should have 5V and 0 amps being drawn.
Now plug the tablet in and see what you have, generally you will see a charge current of between 0.5A and 2.5A depending on the type of tablet and the type of USB charger. If you get no charge current then check the socket, this customer has loosened the socket by constantly wiggling it trying to get it to charge so that was first thing I fixed
Now watch the charge current. Once the chip on the tablet has decided to charge the battery it will modulate the current depending on what the battery management tells it. So now it's trying to charge at 500mA
Unfortunately for this customer the battery needs replacing as well. After trying to charge for around 15 mins the current dropped to 40mA because the battery is shafted. So in general no current pull = socket bad and these micro USB's do generally fail .... and 500mA start charge current falling to virtually nothing means battery is duff.
So for £4 it's quite a bargain tool to help work out what's wrong. I doubt it's calibrated to a high standard but it doesn't need to be to show you what's happening charge wise.