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..
After getting life back in the BM7000, I hooked up a BC7000 to see what the next step would be.
When pressing play on the BC, the beomaster turns on, and in the BL7000 I can see the status of the BC fine. It changes status, displays tracks and shows dolby changes and so on when I do close up control on the BC, so the BC tells what is going on to the master, and it tells it again to the remote.
But the other way around, nothing happens ? The beocord cannot be controlled from remote and do not turn off at a long press on std.by direct on the Beomaster..
How is that possible ?
Any ideas ?
/Jacob
This was the lightning damage case? Expect anything. The Datalink lines are directly connected to the bidirectional I/O pins on the CPU, and they can fail this way due to overvoltages (don't even need a lightning for that).
--mika
tournedos: This was the lightning damage case? Expect anything. The Datalink lines are directly connected to the bidirectional I/O pins on the CPU, and they can fail this way due to overvoltages (don't even need a lightning for that).
Yes, the lightning unit.. So even though everything else works, and datalink the one way, this might be the CPU that has been damaged ? Will have to put the scope on the datalink ports later, to see what happens on them later tonight :) It sounds plausible though, that it is a processor damage, since it works one way, I can see there are 3 pins specified datalink, but maybe one of them is dead ?
It should be possible to find a new 80C32 and change it if that is the problem :)
Can the 80C32 from a BM4500 be used ? Are they programmed from factory, or by the EEPROM with the SW ?
Weebyx: tournedos: This was the lightning damage case? Expect anything. The Datalink lines are directly connected to the bidirectional I/O pins on the CPU, and they can fail this way due to overvoltages (don't even need a lightning for that). Can the 80C32 from a BM4500 be used ? Are they programmed from factory, or by the EEPROM with the SW ? /Jacob
Forget that :) I read quickly about the 8032, and it just runs the program from the EEPROM, so I will try to test with the scope later, and if that does not seem right, I will take a 8032 from a BM35/4500 processor, and see if that does anything :)
Would you recommend to solder out the backup battery while changing the 8032 ? It needs changing anyways, but for now I would like to just mess as little as possible while finding faults :)
80C32 (CMOS) is in principle compatible with 8032 (NMOS) but there are minor differences. It might work but I wouldn't try mixing between them as long as a correct replacement is available.
There are several Dataling buses in the Beomaster, that's why the CPU has three different I/O pins driving them. One for Beogram and Tape, another for Beogram CD and Tape2, and the third one for AUX etc.
These CPUs have nothing that is backed up by the battery (it's a separate NVRAM / clock chip that needs it) but it would be safest to disconnect it. Remember that all the settings in the Beomaster will need reprogramming when the battery is disconnected.
Just a quick update... Lightning has done some damage :)
It appears that there are some issues with negative voltages around the unit. The datalink actually works 2-way on the TP2 source, but not on other sources. So I suspect that the source select chip is dead. I am also measuring -53v on one of its legs...
The tuner board is also dead, it searches, but never tunes to a station, so maybe it is just a write off as physical parts :)
tournedos: 80C32 (CMOS) is in principle compatible with 8032 (NMOS) but there are minor differences. It might work but I wouldn't try mixing between them as long as a correct replacement is available. There are several Dataling buses in the Beomaster, that's why the CPU has three different I/O pins driving them. One for Beogram and Tape, another for Beogram CD and Tape2, and the third one for AUX etc. These CPUs have nothing that is backed up by the battery (it's a separate NVRAM / clock chip that needs it) but it would be safest to disconnect it. Remember that all the settings in the Beomaster will need reprogramming when the battery is disconnected.
Both Beomaster 4500 and 7000 uses 8032 chips, so I guess it is safe to exchange those? But as long as I do not measure correct voltages around the source selector, I might not win anything changing that processor just yet.
Your remark with the different DL busses makes sense, regarding that the sources acts a bit different :)
Will do a bit of measuring with a scope later, just to see if there is AC voltage where there should not be. Have just used a DMM to measure up until now.
The problem was not the processor, there was 2 diodes under the relay board that was dead, one with flow both ways, and one with no flow in any direction :)
2 new 4148's and it worked again :)