RADIO WONT WORK

The volume control pod needs to be flushed with electronic control cleaner, unplug and remove back, attach supplied straw and give the pod two or three good blasts in the tiny hole and rotate volume back and forth rapidly to reach desired results.

These problems can be the result of a bad chip (integrated circuit) on the display board or controller or a simple loose connection. Loose connections happen mostly in mobile applications due to vibrations, bumps, etc. Almost everything can be repaired - but often it is simply not worth the expense. You may be able to make a repair to a loose connection on your own if you have some soldering skills.



"Before" shows a small crack around the post. The component on the other side was disturbed before the solder at the bottom cooled completely, resulting in a cold solder joint. Adding a small amount of solder repairs the joint to "After".

The first thing to do is determine if there is a loose connection or "cold solder" joint as shown above. Only attempt this if the radio is a mobile radio - or otherwise powered with less than 30 volts or so. Base radios (connected to your home's AC mains) should be brought in for professional service instead. First, check for a loose connection while powered up by attempting to slightly move the display. Apply pressure to the top, bottom, left and then right side. Watch closely for an indication of the bottom segments of the LCD turning on. Next, open your radio to access the display PCB. Duplicate the movement if it turned on the display, again. Look at the areas that connect the display PCB to other parts with solder. Try to find the places that expose a crack while moving the display. If none are found, look for the location(s) that are stressed when the display is manipulated. If the display is not turning on at all, look for cracks on the PCB associated with the display. You may need to try to get some movement of this PCB(s) to get the display to flicker on and off. It is very important to keep fingers and tools away from the small coils of wire on the PCB(s). The slightest deflection of the coil can cause major problems for the radio and the operator if it transmits out of the intended band. If you can not get the display to flicker on and off, there is probably a component that has failed. This will require pro service to locate and correct. Likewise, if you are unable to determine the soldered point(s) that when moved, cause the display to flicker, or are uncomfortable soldering small parts, etc. you should bring the radio in for pro service.

If you decide to attempt a repair, a small, 15 to 30 watt iron is maximum size to be used. Gently heat the suspect solder joint(s) to restore the connectivity to the display PCB. If you located a cracked PCB, the silver "traces" on both sides of the crack will need to be joined. Sometimes, a small blurb of solder can bridge the crack, other times a length of wire is needed to do the job. Use only as much heat is required to melt the solder. Too much heat will damage the PCB and / or components on the PCB. When done, carefully inspect your work. Look for accidentally "bridged" connections, as shown in the red circle in the image below:



You may need to solder wick or solder vacuum bulb to clear these bridges. Check your work twice and reassemble to test.

I hope this helps and good luck! Please rate my reply. Thanks.

Hi , LOC means radio is locked....1. You can retrieve a set of factory numbers in the radio that enable you to get a unlock code . If it says INOP you will have to leave the key in the ON position or let the car run for at least an hour before you attempt any unlock procedure .INOP means a secondary theft lock due to too many attempts to unlock radio........2. look at the face of your radio and hold down the preset buttons 1 and 4 or 2 and 3 ( depending on year and model , if 1+4 don't work use 2+3, ) for about 10 seconds or until a set of 2 or 3 numbers come up on the display. Write these numbers down.......3. Next press the AM/FM button, a new set of numbers will now show. Write these numbers down. You will then need to call an 1-800 no. with the numbers you have written down to get the unlock code. Try calling a GM dealer and ask them to do it for you, or some sites on internet will get for you for a fee.....4. Once you have the unlock code enter it by pressing the MIN button until display shows the last 2 digits of the unlock code, then press the HR button until the first 2 digits of of unlock code are shown. Then press the AM/FM button to enter the code. The radio will now display SEC and normal function is restored.

Typically, these radio displays go dark because the surface-mount resistors on the circuit board crack loose from the board after a few thousand operating cycles.
How handy are you with a soldering pencil?
You need a special 5-sided tool to loosen the two screws under the little doors in your radio face. You can buy those tools on line, or if you are lucky, you might be able to loosen those screws with some other sharp object
Then you pull out the radio and unplug the wires from the back of it. The big plug is REALLY difficult to release and unplug, so it might be easier to just work on the radio with it dangling from your dash.
Take the top cover off the radio. Then remove the four screws that hold in the cassette carrier and pull it out. A magnetic screwdriver is really helpful for this job. Those tiny screws can get away from you. Take the face off the radio. No need to pull off any knobs or buttons, just remove the screws, release the snaps across the bottom, unplug it, and remove it.
Now, near the font edge of the circuit board you will find several tiny surface mount resistors. They are rectangular and not much bigger than grains of beach sand. If you look at them with a magnifying glass, you will likely find that one or more of them have cracked solder joints. If you can freshen up those solder joints with a sharp soldering pencil, your display should illuminate again. I have fixed both the displays in the radios in my two '97 328s this way.
If you unplugged the radio and pulled it out, you will need the radio code to restart it. If you did not get the code from the previous owner, the dealer can get it for you if you give him the serial number off the radio.

Hi there!!

It looks like your problem would be your Voltage regulator has either went bad or if your radio is mounted in a truck that vibrates alot then one of the three legs of the Voltage regulator has broke loos from the board. If you do not have experiance in electronics or soldering you should let a Radio Tech. do it for you or you could damage the radio!!! If you choose to do it your self then you must disconect from power then take the covers off of the radio. Turn the radio up side down and look inside the radio you will see the PC board has many compnents inside and beside each one there is a letter and numbers followed by the letter. look to your right and you will see a smaller PC board mounted to the right side with 2 screws to the out side of the chassis. Remove the 2 screws and carfully move the board out of the way so you can see the main PC board. Look down on the right edge of the main PC board and you will see a small black transistor with 3 legs on it the number on the PC board is TR41 when you find it turn the radio over and inspect the 3 legs that are soldered to the PC board and look for a crack or loose solder joint if you find one resolder it or resolder all three legs. If there is indeed a crack or bad solder joint then resoldering it should bring it back to life again!! If not then you may need to replace it with another one!! There is another transistor not to far fron the voltage regulator that may have went bad too it is TR40 that works with the regulator but is unlikely the problem but you never know. Try TR41 first it should fix it for ya. Feel free to E-mail us with any other questions that you may have at: [email protected]

Thanks Dennis

Six stations for each band can be stored. 1 Press LIST.
Preset screen is displayed.
2 Use MULTI-CONTROL to store the selected
frequency in memory. Turn to change the preset number. Press and hold to store. You can also store the frequency in memory
by pushing and holding MULTI-CONTROL right.
3 Use MULTI-CONTROL to select the desired
station. Turn to change the station. Press to select.
You can also change the station by pushing MULTI-CONTROL up or down.
To return to the ordinary display, press BAND/ESC or LIST.

I know what you mean. Used to be a source of irritation in this otherwise super-quiet car. It was like "hey... the music plays far too loud now please drive a little slower dad". Really irritating on the Autobahn, constantly fiddling on that volume knob.

Interestingly, the instruction manual for the business CD main unit gave no clues at all! Then I found the solution at the bimmerfest BMW forum:

"
1.Power down the unit (using the knob) and power back up in the radio mode
(either AM or FM).
2. Hold down the "m" button (right of the display) until your display shows
a serial # xxxxxxxxxxx.
3. Using the "+" or "-" buttons that surround the center "musical note
symbol" button to the left of your display, scroll until "GAL 3" comes up,
which is factory setting. Using the number buttons 1 thru 6 below your
display, press the number "1". Your display will now read "GAL 1 ".
4. Power down the unit again (using the knob) and when you power back up,
your new setting will be effective!
5. To confirm that the new setting is active, repeat steps 2 & 3 to check
your "GAL" setting.
6. Enjoy your HK unit's volume the way YOU want to hear it!
"

I assume there are slightly different versions of this in different models but it goes something like this, the keyword you are looking for in the menu system is "GAL" which is a German acronym for speed-sensitive volume control (Geschwindigkeitsabhängige Lautstärkenregelung für Radio).

Good luck!

seems to be a common problem with these radios. check my post at what to look at . the mosfet guy.

Pioneer has a repair service center in California. Look up warrenty and service repair on their site. With a problem that detailed it realy cant be narrowed down to one thing. The good thing is you have enough wrong that you actualy benifit from their flat rate fee's for repair.

Me on the other end ended up paying $200 for them to replace a fuse. :( So yeah look up the repair centers number, give them a call and they will tell you what you need to do. The unit is repairable.

I've got a simillar problem... will be looking into it this weekend. U402 is supposed to be the 5Volt regulator.
The input to U402 is U401 its a 12Volt regulator.
You should check both...