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
I acquired an used BM 4500. At the first test device worked sluggish, response to the BL1000 commands was slow, and operation seemed to be little bit random. I did not tested with speakers/audio. But volume indicator worked as expected, pressing up added the volume number and down decreased it - after a second or two. I had read that battery (3V) might be dead, so i did change it to new one. After battery change device started to show "COdE". I found that 1-2-7-1 trick should help, but no luck with that. The first problem might be the reason to this..
So do you have any idea what to check for repairing sluggishness and code? Some voltage point check maybe? Crystals or frequencies?
Thanks
Tane
Did you do it this way ?
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Display shows "CODE"
Symptom:
"CODE" is written in the display.
Cause:
This can happen when changing RAM or lithium battery, or with failures in the circuit around these components.
Solution:
After repair, switch on the unit.
The unit must NOT be in option 0
0 0 1 61 350 Symfoni Software 2 1 410 14.0 96 800x600 Normal 0 false false false DA JA X-NONE
On beolink 1000 (in audio mode), press 1-2-7-1, and after 3 seconds disconnect power to the unit, and shortly thereafter, connect power again.
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Make sure that you have pressed "RADIO" on your remote before pressing 1-2-7-1..
/Weebyx
How I can check that unit is not in Option 0 state? And if it is, how to change it as there is only "code" on display and no response for anything. Even test mode do not seems to work.
I tried several times to give 1271, and yes did press Radio before that.
Hopefully this is not the issue with yours, but I had a Beocenter 9500 that had a lot of similar just very sluggish and erratic behavior (on mine, the timer would randomly go on, or OFF when I left it on to test and the station frequencies were all off). I too was told that the battery could have been the culprit, but even after replacing it the behavior continued. This all began when I was plugging into a power strip and I didn't make good connection so the unit rapidly switched on then off then on again during the plugin process. I finally dumped that one on Ebay cheap and wrote it off as a bad processor unit. I had more reinforcement of this when the *next* 9500 I got which I swapped some parts from *also* had a dead battery, but had none of the same symptoms other than COdE when it was unplugged and plugged back in.
The BM4500 and BC9500 are actually very close brothers as the 4500 is essentially just the 9500 without built in cassette and CD (and also without two way comms in the early version).
Playdrv4me, your 9500 symptoms sounds similar to my BM problems.
Does someone know how to fix that kind problem? Is the problem source known, so if I replace processor / power / ir /.. pcb with working unit, do that fix it? If so, then the replaced part is broken somehow - can it be repaired?
Thanks for replies
At least i have a good looking BM4500 chassis... If some one has working BM4500 that have poor condition chassis, i am keen to get it. Or even the main electronics are enough.
I think our problems are in fact similar. Just thinking of some of the things mine was doing. If I left it on (sometimes I like to leave music playing or the TV sound to give my dog company and to make it seem like someone is home for example), I would come home a few hours later and it would just be off. Other times it would randomly turn ON in the middle of the day or night. It would sometimes be sluggish in adjusting sound settings, and like I said, all of my radio frequencies were not actually the station that was tuned, but something else. I'm pretty sure I fried some part of the CPU when I was plugging it in that day because all of this happened after that.
I did exactly what you're saying. I found another one that had a bad CD player (common issue), swapped the CD player and my glass panels because I had already gone to the trouble of glueing them, and my metal panels because they were in nicer condition. I also replaced the battery in the "donor" unit just as I had done with mine, put it all back together and did it that way. Sadly, in the process of doing this I broke the cardinal rule of BC9500s and opened the "parts" chassis without securing the glass and broke one of the PERFECT glass panels, so that took away some value from the "bad" unit when I put it back up for sale on ebay. I sold that one and kept my newly refurbished parts chassis and haven't had any issues like that since. Knock on wood!
tane:Some voltage point check maybe?
that was my first thought as well. Not only low voltage at the battery or other points, but maybe some kind of noise (interfering impulses) to the keyboard or processor. Keyword: electrolytic capacitor. How does it react to the remote, when the keyboard is disconnected? It's hard to observe, because the display is not working. Or switching to tape or cd?
Until now my 9500 works fine, and I have no experience with that kind of fault.
Your other idea: defective crystal or something around the internal clocking (because radio frequencies were not at the right point) is also possible.
Chris
Thanks for tips so far
Yesterday i did measure some voltages from power supply (pcb03). While measuring microcomputer (pcb04) was disconnected. I made mistake by shorting 5v to ground (i think) and that blow fuse 1. So now i do not have 5v... I noticed that D28 was replaced with two other kind diodes in series. That might be ok, but i will change right diode in future. Also TR18 was changed to BD244C (original was BD534). The new transistor maybe ok, but should i change it by original type transistor? After i get 5v back i can continue measuring. Without 5v and microcomputer board attached 30v part of psu do not start and those voltages cannot be measured.
tane:Also TR18 was changed to BD244C (original was BD534). The new transistor maybe ok, but should i change it by original type transistor?
No, this BD244 can even stand a little higher voltage (100 instead of 60) but that is a level, that would never be reached. The diode should be a 5.6V Zener-diode. If there are two in series, the voltages have to be added. But it is not rally needed for a proper function. It is a over-voltage-protection to blow the fuse, when the voltage exceeds that level.
Today I got new fuse (F1) and BM has now 5v again. I noticed that 30V circuit does not start. Unit is still showing "COdE", i think that RL1 is off in this state.
Also noticed that 50/60hz signal is not visible after TR19 (red). It can be seen from resistor R114 (yellow). If i understand correctly this hz signal is used By RAM for timer. Should that signal be possible to measure after TR19?
Hi,
yes, the relays are not powered, when they switch on (active in stand-by)! That is annoying me too.
You are right, the 50 Hz should be measured. If there is no high level, the transistor is possibly short. Try with a ohmmeter to ground. When you desolder the transistor or only the collector, the 5V should be there (at the joint). It's coming from pcb4 via a pull-up resistor. (Diagram D, connection C42). If so, change the transistor.
Thank you!!
The „Radio“-thing was my Solution!!