Friday, April 30, 2010

VX-8R Update on the IC's

Some of the VX-8R chips are: A DF2370VLP34V CPU which is based on the H8S/2000 core processor and has 34MHz speed. A CMS589AD5 GMSK modem chip and a V24100 AM/FM radio chip.
Here are the datasheets:

Saturday, April 17, 2010

VX-8R led modification

This is how i modded my leds on the Yaesu VX-8R.

Since i do not like the orange color provided by Yaesu i changed them to something that suites my taste, you can use any color leds you want.

At first get a VX-8R.

Remove the battery and antenna (and the pouch if you have it on) and then remove the two screws at the bottom.

Then remove the plastic insulation cap from the mic and antenna connector.

By holding the dial use a philips headed screw driver and remove the dial, it should look like this.

After you do this then remove the ring crews on top of the dial and mic connector with tweezers or a screwdriver etc.

It should look like this.

Remove the sidescrew that holds the charge connector cap.

Then lift the board and backpanel from behind gently with a flat headed screwdriver and then pull the whole device downwards the bottom of the device. This should remove the assembly and you will end up like this.

Now be carefull and watch close the flex assembly around the LCD, it's glued and you have to remove that gently to avoid damaging it. You can use plastic tools for safety and lift it up. If you don't remove this you cannot seperate the interface board from the baseband module. This is how it looks removed.

Now you can take the two boards apart and set the baseband module aside, we need the interface board in the front.

Now you have to remove the LCD, to do that you will have to unscrew two philips headed screws from the backside of the pcb, do not remove the shielding, just lift it and use a screwdriver to remove them. then lift the lcd.

Now this is a part where you have to be carefull cause you may destroy the lcd connector, if you do that bye bye VX-8R, if you don't have the required tools you cannot replace this connector if you break it. Use a plastic tool and if you can use a tool that is as wide as the connector, gently lift the black bar of the connector upwards and the lcd flex should be instantly released, just BE CAREFULL.

After removing the lcd you can remove the mic connector wich has a similar connector. You will end up with a board that looks like this and you may now get started replacing LED's.

Now you can start removing the LCD leds, here you can see one removed. For this modification i used only a soldering iron and high quality desoldering wick and flux. Start and replace one by one taking care to use the correct polarity.

The led's have been replaced, note that i didn't actually used the same side led's but they are large enough to fit. After soldering use a flux cleaner and clean the board, you do not want to leave a fluxy mess inside such a device.

This is where a stereoscope comes in handy, on the keyboard leds i remove the old led and clean the pcb pads, after that i place some solder on one end of the led contacts and solder one side first just to set the led on the correct position and then solder the other side. Here you can see how it looks with plenty of gel flux on it.

This is how the board looks like after the leds have been changed. Now the board needs to be cleaned with flux cleaner several times. You do not want to leave traces of flux inside. After that you can assemble the board and unit and start using it.

Now the unit is assembled and tested. Sorry about the bad pic. Take care not to touch anything else with your soldering iron or you may destroy something. Also take care on the switches in the front because if you short something out with solder you may loose the keyboard functions, you can repair it for sure but you ahev to re-open the device. Also make sure to be gentle on the gaskets and plastics to avoid compromising the waterproof seal of the radio.

Feel free to contact me at for any questions. I am planning to make a video on how to open the device in case you have questions about opening the device. If you wanna help me out click on some ads.