VX-8GR Service manual / Technical supplement

Here is the link to the VX-8GR service manual for download, finally i found something.
I just hope i'll find the VX-8 one.
https://rapidshare.com/files/839372347/VX-8GR_SM.pdf

Please donate 1.000.000 euros cause i'm out. lol

Lenovo X300 freeze problem

I have seen many users complaining about their lenovo X300 laptop.

My friend has one and had the same problem, it wasn't even able to boot windows and froze up.

We decided to open it and check it out. Seems that the problem is on the hardware side rather on software.

The Intel SLAHZ LE82GS965 (it's a VGA-memory controller chip) needs a reflow or a reball. On the picture above you see a snapshot right before the reflow.After that the laptop works like a swiss clock without problems.

Below you can see another board from a Sony VGN-NR series laptop with vga problems, this was also solved by reflowing the Nvidia chip.

SOIC soldering quick video

A testing video i made.

HTC Leo - HD2 Touch screen change

An old customer-friend who lives in the same area as me brought me his HD2 with a broken Digitizer. On the newer models of HTC it doesn't worth to change simply the digitizer. He bought a digitizer only from ebay. I'll give you some info on WHY HTC asks you a lot of money for a simple LCD or touch screen change.

Since the diamond era many of HTC's phones have the same construction like this. New phones are slimmer, way to slim, so they had to find a solution to fuse everything together. The LCD is factory glued to the digitizer and sometimes part of the chassis. The HD2 has allmost half of the phone fused together.
When i say fused i mean that parts are hold together by a thin double sided sticky foam, the glue holds very tight in place. If you take the individual components apart, you are not actually remove the glue, you just destroy the foam so it's impossible to glue the parts together again. The LCD is so slim now that breaks with a blink of an eye.
On the other side you have also contamination, unless you have a clean room, it's allmost impossible to glue the lcd and touchscreen together without having small dust particles or pieces of glue between them, even if you succeed (like i did half an hour a go) the end result will be messy.
I have good experience on repairing phones and PDA's (i was the owner of an official HTC service center some time a go) and even so it took me 2-3 hours to seperate the lcd, broken digitizer and chassis and glue them together again.
That time means money on big companies, they want to minimize that and also the rate of success, they simply change half of the phone and they are set. This also enables them to give you full warranty if the part is faulty etc.

LCD's and digitizers are glued together even on very old models (like P3300 etc) but at that time only the lcd assembly was changing.
On newer models you have a capacitive touch screen plus the whole face of the phone, plus buttons etc etc so the cost is higher.
Below there is a pic of the touch screen i removed:

If you want to replace a broken LCD or touch screen simply buy THE WHOLE LCD ASSEMBLY, it will save you time and possible frustration on the result. Most of the new models need the whole assembly.

New pics from my decapping project

In the first two pics you can see the damage been made by the drill i used. Only a fraction has been revealed with the drill and the rest was made with nitric acid.

Both of the mcu's were damaged because i used a small tweezer to clean up the excess debris without the ultrasonic cleaner.

Lesson learned: No more tools inside until the whole wafer is exposed. I have to be careful with the drill too.

VX-8R docs

Seems the ham community missed the VX8 series radios.
Most of the sites are not updated regarding the user or service manual or the device. Lack of info around the handheld is 90%.
Wtf happened with this one? In the older days people people were building projects around handhelds or torn it apart to mod it etc.
Maybe Yaesu has been left behind a bit. If i could design a handheld i would make sure to have a USB interface for a PC, maybe pack as many features i can inside,  remember times have changed, people use computers for everything and the market tends to work near computers.
One of the problems i see is that they do not use new technology very efficient by using old parts or complicated designs, yes they are reliable as hell but radios lack of some features that in the newer days are mandatory.
Someone might say "if you pack too many features inside then the handheld won't be reliable or will have crappy performance"
Not true, newer designs can use far more reliable parts and circuits. Newer microcontrollers (like the PIC32 etc) can offer more but the manufacturers still choose small ARM architecture MCU's.
Then there is the problem of copyright and FCC etc, but anyway if someone wants to copy or mod  a design he will do it no matter what, remember the nokia BB5 series? They "used" to be the most secure platform and now it's an every day unlock.

MCU decapping for live analysis

Hey!

I was decapping some PIC MCU's lately (PIC12F629, 18F4550, 18FC452, 16F876A, 16F84 etc) for live analysis. Mainly for training my hands on and some security bits erase.

I got the ideas from Sergei Skorobogatov's page and Bunny's blog the first one is one of the best sites i've ever seen on MCU security.

So i started.

One thing  was annoying was the YELLOW light from the stereoscope lightbulb, so i thought i change the bulbs with newer technology LED ones.

I purchased from ebay for about 2$ two festoon 36mm led lamps and plugged them in.

Surprise suprise!! The stereoscope has only a transformer without any other circuits and the led was only flickering at 50Hz. Damn!

I made a quick perforated board power supply with filtering using the 78S12 regulator and presto.

Note: Images show only the under side of the scope (which i do not use). There is also a LED lamp above. You can see part of the board with the regulator and heatsink (when you have the led's on it's barely some degrees over room temp).

I like it, now i can proceed!

I'm using a drill to create the first pit and to eat away most of the black rosin from the chip and then i use 70% Nitric Acid to burn through it. Nitric acid works best when heated around 70% and i found out that my pcb preheater works fine for this.

Stay tuned for more.