Bang & Olufsen BeoCenter 5000 - part 1. Repair? Is this going to be brain surgery?

[@Salty_Sassenach]

I had one of these back in the 80s 😀. I was blown away by the brushed aluminium & wooden side trim styling which looked beautiful. I have lots of fond memories of the 80s 😀

[@electronicsoldandnew]

Same here 😃

[@EsotericArctos]

I am glad it's you and not me doing this one !. It is going to be a tricky one.

[@electronicsoldandnew]

I get that feeling, yes.

[@EsotericArctos]

@@electronicsoldandnew I am with you on the digital thing too. I think this model shares some bloodlines with the 7002, which had a remote control. That would explain why they want microprocessor controlled. It was a very nice unit when new, despite the processor control. I like valves/tubes myself though :).

[@vintageradiosfernandoberna6041]

Excelente explanação inicial sobre o equipamento, e principalmente sobre o microprocessador, vamos aguardar o proximo video. Saudações - São Paulo - Brasil

[@electronicsoldandnew]

Obrigado

[@lyntonprescott3412]

I used to look in awe of B+O stuff when I was much younger but it was way above my price level. Finished up with a Dynatron record player/radio music centre which my father and I shared the cost. Still got the unit in my bedroom and it still works! The record deck is a Goldring GL85 which is very nice.

[@electronicsoldandnew]

I think all of us were awed by that brand, and even more so by its prices :)

[@lede-soudeur3937]

bonjour , j'ai besoin d'aide sur une b&o center 7000 ...je n'arrive pas a comprendre le mécanisme d'ouverture "soft" du paneau de commande ,j'ai le shémat technique et j'ai démonté le mécanisme pour le réparer (plastique cassé collé avec de la résine) ,les pieces sont ok mais ...comprend pas ! auriez vous des photos en gros plan svp , please

[@alfredneumann4692]

Unfortunately i have no knowledge about the 8048 Microcontroller. The 6502 from Mos Technology was my horse for a longer time in the Apple ][. But it sounds like a new challenge! Keep on, i'm your guest :-)

[@electronicsoldandnew]

Yes, at the time the 6502 and the 8048 were part of the two main families of processors that were competitors in the market. I remember learning the Assembler language for the intel family, and not understanding the other one at all.

[@geirendre]

Yes, any of the larger BeoCenters will be a challenge because of the complexity and often uniq solutions they use, but isn't that part of the fun (at least when you succeed)? Considered taking the processor out and wireing it up on a breadboard to test if it works? Good luck.

[@electronicsoldandnew]

Yes, the challenge is the attraction. I’ve removed the mp and am manually feeding the signals into the respective socket pins, but at the end I’ll do the reverse on a breadboard.

[@kennethiman2691]

Nice. Looks to be a nice project.

[@electronicsoldandnew]

We’ll see :)

[@saarike]

Nice! This is interesting. I'll wait for part 2.

[@electronicsoldandnew]

Coming soon!

[@saarike]

@@electronicsoldandnew My humble thanks.

[@migsvensurfing6310]

If the cap on the cpu reset pin is leaky, you can get all sorts of errors including the cpu coming to a total halt. You might try to change it with one of the same value (dont use other value, reset timing is often but not always critical). Good luck.

[@electronicsoldandnew]

The electrolytics on the cpu board have been changed, with no effect. The quest continues 😊

[@showstopperrob1097]

Hope you have found all Fuses, some fuses looks like a cap. If I were you, I would replace those IC's before the processor including the Crystal. Even crystals can give weird signals. I've noticed this myself

[@electronicsoldandnew]

The chips seem to be reacting as they should, and so is the crystal. We’ll see.

[@Oldgamingfart]

You know what I'm gonna say: Get those Roederstein's outta there! All in good time, I know! This should make for a challenging but interesting project! :)

[@electronicsoldandnew]

Fingers crossed!

[@horaciobichi4216]

Where are you from? I´ve got a bunch of 8748 & 8749, NOS, that I bought in the middle 80's.

[@electronicsoldandnew]

I live on the island of Madeira. I can´t actually use the blank chips because I don´t know the coding they burnt into it. Thanks.

[@konohh]

OK, it's a "digital" repair then. The approach to attack the problem by implanting an ATMEGA Micro, programmed with ARDUINO, sounds like a very interessting project to me. (Maybe it's somewhat more easy for me as I'm more home at the microcontroller stuff as on the analog front). I stay tuned and maybe I can be of help.

[@electronicsoldandnew]

I go for very long periods without doing any programming, so it’s always a refresh for me, which can be a pain. Thanks for the offer. We’ll see how this goes.

[@waynethompson8416]

I may be misunderstanding you, but it sounded to me like you were saying that the processor chip was providing signals to the Program Select (IC7) chip. At the EE FF and GG points below IC7 there are arrows that are pointing in the direction of the processor. Which to me would indicate that IC7 is providing the signals to the processors. Am I missing something here? You and I seem to think a lot alike on the digital mixed with analog issue. To me, it seems that simple processes are often overly complicated by inserting digital into it. They work, and work well, but is the digital really providing anything in the way of an improvement to the device if it were all analog? Looking forward to the other videos on this unit.

[@electronicsoldandnew]

No, from my understanding the processor supplies the select code (it is shown as outputs in the truth table). The arrow is an indication of the direction to follow to find the connecting link in the drawings, not the signal direction. I often prefer the old and tested versions of things, even if it means I have to get up to change the volume.

[@osliverpool]

"Mixing microprocessors with a piece of audio gear is an aberration" - I agree 100%. I even heard today of speakers that need firmware upgrades! What is the world coming to?

[@electronicsoldandnew]

We’ll all be walking around with built-in speaker chip in our ears :) oh, wait. They already do ... Bluetooth ear-buds. The world’s going crazy 😝

[@matthiaskolling7495]

Whats the problem with the microcontroller? Maybe it's a simple issue (oscillator, reset).

[@electronicsoldandnew]

This project is on extended leave 😊

[@EngineeringVignettes]

Feel free to upload a part 2 or not, I will watch it and probably like it if you do :D Cheers, hope you are not getting cabin fever too bad... are you allowed to go 'walkabout' on the island? - Eddy

[@electronicsoldandnew]

We can now leave the house, but everything is practically closed down. Not fun.

[@lennartbenschop656]

You say: Mixing microprocessors with audio gear is an aberration... But you are a fan of Bluetooth receivers inside tube radios and did you know how much processor power is inside a BT reciever?

[@electronicsoldandnew]

You got me! I know, it makes little sense. However, in my (rather weak) defence, the BT module stands alone and if it aggravates me, I just remove it completely. The BT module also probably has 1000 times more processing power than the CPU in this thing, so, as I said, you got me :)

[@lennartbenschop656]

@@electronicsoldandnew And of course for repair, if the microcontroller itself is broken, it is impossible to replace. You could still buy 8048 compatible processors, but without the contents of the ROM, it won't be much use. You need an EPROM version of that processor, then you nneed a programmer and the file with the original ROM contents. If anything else is broken (power supply stuff, clock crystal), you can probably fix it.

[@peterjmcgee4680]

My question to you have you scoped chip yet see if you're getting the signals

[@electronicsoldandnew]

Some are there, others are dodgy.

[@lyntonprescott3412]

P.S. good luck with the repair of your unit.

[@electronicsoldandnew]

Thanks

[@anandarochisha]

Arduino plus B&O = Bang & frankenolufsen

[@electronicsoldandnew]

True

[@DerekHerbst747]

You're scraping the bottom of the barrel here.. 🤣🤣

[@electronicsoldandnew]

I never thought I’d arrive at a time when B&O would classify as the bottom of the barrel :)

[@jdmccorful]

Interesting project. Follow the rabbit.

[@electronicsoldandnew]

I can’t resist :)