Radio says ' WAIT' & Does Nothing.... - Page 2 - PeachParts Mercedes-Benz Forum

vwnate1 · #16 02-14-2017, 09:43 PM

Yes, I assume the 'A' prefix makes the serial # 8 digits......

I don't want to leave the key on for 24 hours, not sure I can as I drive the darn thing daily .

VT220D said he'd get the code if I posted the serial # . (hoping) .

I live on less than 30,000 / year as I'm disabled & retired so I have to watch every $20 I need to $pend .

TIA,

vwnate1 · #17 02-14-2017, 10:01 PM

Ah, HA !

.

I figured it out and retrieved my four digit code, now I guess I'll need to leave it plugged in with the key on and everything else turned off overnight and if that fails, for TWENTY FOUR HOURS to see what happens.....

Stay tuned .

VT220D · #18 02-15-2017, 09:24 AM

Glad you found the code! However, the serial number you gave is only 6 digits. It should be 7 digits (not including the letter).

The code calculator only uses the last 4 digits of the serial number. As long as the last 4 digits are 6296 your code should be 8910. If that isn't the same as the one you retrieved double check the serial number and post it. If you enter the wrong code too many times you'll need to wait another 24 hours.

If after 24 hours the radio still displays "wait" you likely have a corrupted eeprom.

FYI: You can't enter the code until the radio displays "code". I don't know if attempting to enter a code while the radio displays "wait" has any effect on wait time but it won't unlock the radio even with the correct code.

During the 24 hour wait check the heat sink temperature on the LH side of the radio. If its uncomfortably warm/ hot to the touch you have capacitor problems. Unfortunately many of the ones I work on require new caps. The heat sink should run around 100 degrees in room temperature air. Radios with bad caps will be 120 degrees or over with significant distortion above moderate listening levels.

VT220D · #19 02-15-2017, 10:27 AM

Some general information on the Becker BE780 and BE1480. These radios often present with a never ending "wait" display. It won't clear even after 24 hours. When this happens the eeprom is corrupted and entering the correct code will have no effect. The only solution is to flash a new eeprom with a known good code.

The replacement eeprom is number 24C01C. They are cheap and readily available from Mouser or Digikey. They can be flashed with a known good code harvested from a working radio. That requires carefully desoldering and reading a good eeprom from a working radio. Once this is done a new eeprom can be flashed using the code read from the good eeprom. However, the new radio will use the same unlock code as the donor radio. In other words the unlock code will match the donor radio and the serial number calculator won't work.

It should be possible to decompile and edit the code from the eeprom to make the unlock code match the serial number derived code. I intend to start that project soon but I haven't had the time.

If you don't solder or tinker with electronics you can swap the entire eeprom board from one radio to another. If you have a radio with problems that unlocks and you want to test one you can't unlock just swap eeprom boards. Just like above the code travels with the board so be sure to write it down. To swap boards remove the top plate then remove the three screws on the eeprom board and gently pry the board off the connectors.

If your Becker runs hot or has audible distortion you will need all the caps near the heatsink replaced. Many times the 3300uf cap near the copper sink is visibly leaking. Another symptom of cap failure is relay cycling on power up. When you have to hold the on button through several clicks to get the radio to turn on the caps are shot.

One fairly easy and common cap fix is the 220uf @ 16v cap on the lower board of the radio. This one shorts and leaves you with a radio that appears to tune but has very little or no sound. This cap can be replaced without removing the board since it resides at the edge of the tape deck cut out. When this cap shorts the board above it gets hot quickly.

When replacing any electrolytic be sure to observe polarity. A replacement cap will usually be physically smaller then the old one. You should stick to the capacitance value (220uf etc.) but a higher voltage part is fine. The caps on the main board near the heat sink require careful sizing. Caps of the same value can be found with different lead spacing, height and width. The 3300uf cap has to be exact - it's a tight fit.

Opening the top of these radios or removing boards requires a Torx T8 driver. The bottom plate just pries off. The top pries off too but has one screw. Be careful getting the plates off. Don't lever inside the radio or pry against the antenna jack. Use a flat blade screwdriver on the rear lip of the cover and tap it gently with a hammer.

As always when working with electronics anti static precautions are a must. Especially in the dry heat of winter. Static discharge destroys parts.

The very similar looking but radically different BE1432 radio commonly found in the W124 and late W126 can supply FM and AM modules as well as a preamp line out module. These modules are found in the trunk mounted portion of the 1432. The preamp out module is attached to the outside and bolts to the rear of the 780/1480. Get the connector to make an RCA adapter for a power amp. A Torx T8 driver is required.

compu_85 · #20 02-15-2017, 10:40 AM

Great post! The tuner modules in there look an awful lot like the modules in the rear unit of my 1432 system.

vwnate1 · #21 02-15-2017, 12:32 PM

@ VT220D :

THANK YOU ! .

This detailed info is priceless .

I'm a mechanic not an Electronics Tech so I won't be doing anything more than swapping damaged face plates .

FWIW, your Pic. # 3 shows where I got the model and serial #'s, they're etched .

Your Pic. # 1 shows the bar code, I noticed that after and used the long combination # from it and ! PRESTO ! I had me a code .

I'll have to go hunt up a spare power plug and wire it up, I have a 1/4 ampere battery charger I'll try as a power supply .

The spare radio I have in it now, works except the AM band ~ there I only get faint static .

I'll tinker with this as soon as I can and report back .

I sent Becker a note asking if they're buying core radios, no reply yet .

THANK YOU ONE AND ALL .

compu_85 · #22 02-15-2017, 12:58 PM

Quote:

Originally Posted by VT220D

...When this happens the eeprom is corrupted and entering the correct code will have no effect. The only solution is to flash a new eeprom with a known good code. ...

This makes me think I should back up the eproms in my current, working setup...

-J

VT220D · #23 02-15-2017, 02:03 PM

Quote:

Originally Posted by compu_85

This makes me think I should back up the eproms in my current, working setup...

You could but I don't think it happens randomly. I copied one after experiments with eeprom board swapping led me to location of the code. After that I began to understand how it works.

Every corrupted radio I've repaired always had cap problems. Once running they ran hot or had power up problems. I strongly suspect that the contents of the eeprom get scrambled when poorly filtered B+ gets to it. Imagine a scenario where eeprom is queried after a battery replacement just as the engine is cranked. All that spiky garbage hits the line and scrambles it. Capacitors working properly would prevent that.

The microprocessor queries the code eeprom after a security trigger on the BE780 or a power interruption on the BE1480. As long as the radio remains powered (but off) the boards can be swapped from good to bad and back. The radio doesn't use the code eeprom unless triggered. I would expect the BE1432 behaves similarly.

So the microprocessor doesn't care what the code is as long as the keypad input matches the code stored in the eeprom when queried.

If you have an ESR tester it might be a good idea to check the caps while you're in there. The BE1432 spreads the circuit over two chassis with quite a bit of volume so it probably doesn't bake its caps the way the BE780/BE1480 does.

BTW: I re-flashed a scrambled one and it works fine. They don't get fried just a wee bit muddled. Also, I checked the service manual for the BE1432 and it uses the same eeprom on the control board.

VT220D · #24 02-15-2017, 02:06 PM

Quote:

Originally Posted by vwnate1

@ VT220D :

THANK YOU !

You're welcome! I've learned a lot here and once in a while I have something to contribute.

Let us know how it works out for you!

compu_85 · #25 02-15-2017, 02:45 PM

Quote:

Originally Posted by VT220D

... I checked the service manual for the BE1432 and it uses the same eeprom on the control board.

Good to know. I did know the security code was stored in the head unit, not the tuner after doing musical parts to get my system working again.

-J

vwnate1 · #26 02-15-2017, 03:55 PM

My basic mantra is : knowledge is useless unless shared.....

Some folks don't ken this basic, common sense concept and wonder why they're so unhappy in life

.

-Nate

Quote:

Originally Posted by VT220D

You're welcome! I've learned a lot here and once in a while I have something to contribute.

Let us know how it works out for you!

vwnate1 · #27 02-19-2017, 03:20 PM

O.K., I have now decoded several BE1480 radios .

I have some earlier models the the yellow backed display that used to work fine but I tried them yesterday and all I get is " -- -- -- in the display area, not sure what to do with these .

I'm fooling with these because my other, radios occasionally being to squeal loudly on the AM band only ~

Some of my spare Beckers will play AM for 5 ~ 10 seconds before it fades out to faint static . what's the deal here ? .

One of those decided to play AM again last night so it's in the dashboard right now , I wonder how long it'll last .

Becker wrote me back asking for model #'s and how many I have for sale, I've been poking around and have quite a few including some older two knobber jobs from the 1970's ~ all are AM/FM , one or two also have medium and long wave bands .

The help I have received is as usual, out standing !

.

VT220D · #28 02-20-2017, 12:28 PM

The radios that display -- -- -- -- have an internal battery that requires replacement. The battery is commonly available. The Tadiran number is TL-5902/T. Even after battery replacement the BE754 requires a special unlock tool. A dealer may have it otherwise it needs to go to Becker. I don't have one. Often these radios are pulled working but end up requiring a battery\unlock after sitting for a short while.

If this battery is replaced on a working BE754 a power supply must be used to keep the board powered while soldering the replacement. If you lose power for an instant you get -- -- -- -- and a trip to the dealer. The BE612 also uses the same battery but only for memory/clock backup. The battery can be replaced without powering the board.

I'm of the opinion that the BE780/1480 are the best plug and play upgrades for the BE612 and BE754. The BE780/1480 radios don't require batteries, have more power, better displays and a preamp out option. All old Beckers can have capacitor problems due to age - so does every electronic module in the car.

The AM fade out you're experiencing is very likely a cap. The one I identified in the pictures posted earlier will cause this symptom on FM. It's quite possible that AM is also affected but my test bench connects to an FM only antenna with splitters that prevent AM reception. For that reason I only test FM to find that fault. I use a signal generator for AM testing.

If that cap is at fault you can run the radio for a minute and feel the board above it with your fingertip. It will be warm/hot. Access to that board doesn't require a torx bit. Just carefully remove the bottom cover. You can probably find that cap at radio shack if you still have one near you. You will need to solder though.