ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
Hi All
I need some input to what could be wrong with a Beocenter 2300 I just have gotten hands on very cheap... The laser is done, but that is just a focus error and a new laser, so no problem there..
The other issue is that the radio is not working, when putting power to the system, and pressing RADIO, the freq shows 000.0, and then after a few seconds, it jumps to 76.0, then I can step by pressing TUNE-> up to 90.0 and then it stops.. There is no static noise or anything. The AUX input is working with sound, so the AMP and all is ok.
If I disconnect the tuner-board completely, the freq goes from 87 to 108, and then by pressing TUNE-> one time, it start searching... Doesn't find anything of course, but at least it does something.
I have verified the +5,+15 and +30 volts to the FM board, and they are all fine..
If I goto servicemode and press 3 to show the tuner-variant, it displays 2.0 which according to my servicemanual(under the BS2500 section though) conforms to JAPAN.. But that might be a SW diff between BC2300 and BS2500, the service manual contains the diff's between BC2300 and BS2500, but nothing about this tuner-variant diff..
The ROM/RAM test passes for all IC's
Any ideas on what to do ? Are there some points that needs resoldering ? Any capasitors that often go bad in the FM board, or is it a SW issue ?
Thanks for any input
/Weebyx
Forgot one thing..
If I press GOTO and enters anything above 90.0, it jums back to 90.0, and anything under 76.0 it jumps to 76.0..
It is as if the FM board is in some kind of "wrong" frequency mode, I do not own an osciloscope or a freq generator, so I cannot do the adjustments in then service-manual. But the old owner said that it just stopped working one day, and he didn't bother getting it fixed. That is why I could hope it was a bad soldering or some other "easy" thing to try :)
Weebyx:If I press GOTO and enters anything above 90.0, it jums back to 90.0, and anything under 76.0 it jumps to 76.0..
Can't help you with the actual problem, but 76-90 MHz is the FM band used in Japan. So this could well be simply some service configuration issue...
--mika
tournedos: Weebyx:If I press GOTO and enters anything above 90.0, it jums back to 90.0, and anything under 76.0 it jumps to 76.0.. Can't help you with the actual problem, but 76-90 MHz is the FM band used in Japan. So this could well be simply some service configuration issue...
Yes, it might just be a SW configuration issue, and that is propably why it reads out JPN in the tuner-variant..
So, how to change this? :)
Hmmm, this puzzles me..
If I look in the service manual, I can find the jumpers that needs to be cut for the tuner-variant-detection, but all the jumpers are intact, so why it is displaying 2.0(JPN) is kind of a mystery...
Sorry, I apparently skipped over the part in your opening post where you had already figured out this to be a Japanese thing.
I have practically zero experience with these units, but looking at the service manual, perhaps the pull-up resistor is faulty / bad solder (or +5V missing for some reason) and now IC4 thinks both of the jumpers are open? That would make it feel like being in Japan...
Thank you
I Think you are on to something here, I actually read about a guy who had issues with the +5V and changed a transistor somewhere, unfortunatelly he didn't mention where he changed it, but since the PCB01 Tuner board gets the +5V from the power supply, then it must be somewhere on the tunerboard something is wrong..
Do you have a High-Res image in your service manual ? My PDF is rather blurry, and I am having trouble locating the SMD resistor and capasitors on the board, I think I will try and measure som voltages around the jumpers, just to see if there are +5V at the pull-up resistor, R61 right ?
Thanks for your help..
tournedos: Sorry, I apparently skipped over the part in your opening post where you had already figured out this to be a Japanese thing. I have practically zero experience with these units, but looking at the service manual, perhaps the pull-up resistor is faulty / bad solder (or +5V missing for some reason) and now IC4 thinks both of the jumpers are open? That would make it feel like being in Japan...
You mean IC3 right ? :)
If I measure from P5(ground) and to pin 9 and 12 on IC3, then there is +5V at each leg on the IC3. Am I correct in assuming that then IC3 thinks that both jumpers are still intact ? And so the issue must be something else ?
If I completely disconnect P6, then the tuner-variant comes back as 0.1 (EU-FM), and then the freq goes correct from 87 to 108, but still no sound :) I guess P6 actually connects tom something important :) But something is wrong in the variant detection somewhere.
Weebyx:You mean IC3 right ? :)
Yep. Apparently that issue should be right then... perhaps there are other points of configuration elsewhere, I haven't read that far as I never had one of these BCs
tournedos: Weebyx:You mean IC3 right ? :) Yep. Apparently that issue should be right then... perhaps there are other points of configuration elsewhere, I haven't read that far as I never had one of these BCs
I have looked at the microcontroller schematics, and it appears that the IC3 should send info to microcontroller, so I don't think that there are other "variant detection" curcuits somewhere.
Could it just be a bad solder somewhere ? The "funny" thing is that the variant changes when removing P6, so the controller detects "something" from the tunerboard..
Do you have any other ideas ?
Weebyx:I have looked at the microcontroller schematics, and it appears that the IC3 should send info to microcontroller, so I don't think that there are other "variant detection" curcuits somewhere.
I took a look at the LC7218 schematics, and yes, pins 9 & 12 are actually outputs instead of inputs, so the microcontroller reads the jumpers that way (another totally devilish idea by the B&O engineers...). This will obviously change things when you disconnect P6, but it doesn't seem to pinpoint any specific problem; just shows that IC3 and the processor can't communicate properly. It could be a bad solder/connection at any of the connectors P6-P7 or elsewhere along the route, with a small chance of a faulty chip.
Sorry I can't help much further - I have never actually even touched one of these upright music centers...
tournedos: Weebyx:I have looked at the microcontroller schematics, and it appears that the IC3 should send info to microcontroller, so I don't think that there are other "variant detection" curcuits somewhere. I took a look at the LC7218 schematics, and yes, pins 9 & 12 are actually outputs instead of inputs, so the microcontroller reads the jumpers that way (another totally devilish idea by the B&O engineers...). This will obviously change things when you disconnect P6, but it doesn't seem to pinpoint any specific problem; just shows that IC3 and the processor can't communicate properly. It could be a bad solder/connection at any of the connectors P6-P7 or elsewhere along the route, with a small chance of a faulty chip. Sorry I can't help much further - I have never actually even touched one of these upright music centers...
Hi again.... Good news :) Never give up...
I did some more probing on then LC7218, and nothing happened on the AM/FM pin, or any other pins for that matter... Ordered a new one from littlediode.com, got it today, changed the IC and voila :)
All is good... Variant detection, FM freq and most important of all, sound from the Radio :)
Just to let you know ...
That's good to hear! Thanks for letting us know, it can always be useful to other people in the future