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General Category => Other retro => Topic started by: teopl on 16:03, 15 September 23

Title: BBC micro reparation
Post by: teopl on 16:03, 15 September 23
Hello CPC friends,

Recently I got BBC micro from a friend to check if it can be fixed.

I have only device and cable to connect it to TV.

Problem: when it was turned on, it showed some smoke and then it was turned off.

I don't know anything about the system and also I am bad with electronics - do you have any advice how to proceed other then to send it to someone across the ocean to fix it :)

I tried first to register to BBC micro forum https://stardot.org.uk/forums/ but this looks like registration is closed...
Title: Re: BBC micro reparation
Post by: Gryzor on 17:10, 15 September 23
I don't know much about electronics either (so, sorry but I can't help) but I do know you don't switch ancient devices on without thoroughly checking then first, or you run the risk of the smoke demo coming up... 
Title: Re: BBC micro reparation
Post by: Rabs on 17:24, 15 September 23
Quote from: teopl on 16:03, 15 September 23Hello CPC friends,

Recently I got BBC micro from a friend to check if it can be fixed.

I have only device and cable to connect it to TV.

Problem: when it was turned on, it showed some smoke and then it was turned off.

I don't know anything about the system and also I am bad with electronics - do you have any advice how to proceed other then to send it to someone across the ocean to fix it :)

I tried first to register to BBC micro forum https://stardot.org.uk/forums/ but this looks like registration is closed...
It will be the Rifa capacitors in the power supply. I had to fixed a friend's BBC and mine.

Title: Re: BBC micro reparation
Post by: pelrun on 20:25, 15 September 23
Yup, it's the rifa cap. They're notorious for it.

Quote from: teopl on 16:03, 15 September 23I tried first to register to BBC micro forum https://stardot.org.uk/forums/ but this looks like registration is closed...

You have to accept cookies on the page before the register/login links are shown. So turn off any browser extensions that might block that popup.
Title: Re: BBC micro reparation
Post by: Bryce on 10:43, 16 September 23
Quote from: teopl on 16:03, 15 September 23Hello CPC friends,

Recently I got BBC micro from a friend to check if it can be fixed.

I have only device and cable to connect it to TV.

Problem: when it was turned on, it showed some smoke and then it was turned off.

I don't know anything about the system and also I am bad with electronics - do you have any advice how to proceed other then to send it to someone across the ocean to fix it :)

I tried first to register to BBC micro forum https://stardot.org.uk/forums/ but this looks like registration is closed...
The BBC PSU's are known to fail with bad capacitors. You just need to replace all the caps, especially the RIFA (looks like a square block of yellowish see-through resin and will have cracks in it). If the smoke smells disgusting it's coming from the RIFA, if it just smells unpleasant then it's coming from an electrolytic cap that has dried out.

Bryce.
Title: Re: BBC micro reparation
Post by: teopl on 13:07, 16 September 23
Thanks everyone, I will take the PSU to the local repair shop and see if they can replace the caps!

I also saw later several youtube videos showing how to fix it and yes, it looks like a common problem.

I have one more question: on some youtube videos I saw that they use caps from prepared "repair kit" ordered online:

Do you recommend ordering such a kit or I can leave the repair shop to choose the correct caps?
Title: Re: BBC micro reparation
Post by: Rabs on 13:32, 16 September 23
I got my capacitor kits from Retroclinic. (http://www.retroclinic.com/) Mark was very helpful.

But repair shop  should be able to get hold of the capacitors, it is a common problem.
Title: Re: BBC micro reparation
Post by: Rabs on 13:47, 16 September 23
Dead Rifas
20230916_134027.jpg
Title: Re: BBC micro reparation
Post by: Bryce on 10:44, 17 September 23
Quote from: teopl on 13:07, 16 September 23Thanks everyone, I will take the PSU to the local repair shop and see if they can replace the caps!

I also saw later several youtube videos showing how to fix it and yes, it looks like a common problem.

I have one more question: on some youtube videos I saw that they use caps from prepared "repair kit" ordered online:

Do you recommend ordering such a kit or I can leave the repair shop to choose the correct caps?

They are all pretty standard caps. A decent repair shop should have them in stock and not need to order them

Bryce.
Title: Re: BBC micro reparation
Post by: teopl on 21:31, 01 March 24
worked great with just replacing caps in PSU... thanks again

I returned BBC to my friend but he wants to sell it to me... I am not sure is this computer any good?

can it be compared to CPC?

I saw there is something called "second processor" and that it could be Z80... does anyone knows something about this?
Title: Re: BBC micro reparation
Post by: andycadley on 00:03, 02 March 24
The "tube" as it was known was kind of a cool feature of the BBC. You could install a second processor in it (a 6502, a Z80  even early ARM CPUs) and run programs in it. The 6502 is the BBC in those cases would actually as an I/O system - programs running on the second second processor could communicate with the main system via a generic I/O protocol to do things like read the keyboard or draw things on the screen.
Title: Re: BBC micro reparation
Post by: robcfg on 00:05, 02 March 24
Well, the BBC Micro is indeed a great computer.

You can check games made for it at https://bbcmicro.co.uk/

Regarding the secondary processors, there were modules back in the day that connected to a high speed port on he back of the computer named "the tube" and there were 6502, Z80, ARM and maybe 6809 coprocessors for the machine.

There's also a modern module using a Raspberry Pi that acts as an ARM processor that will make Elite (literally) fly.

So, if your friend is making you a reasonable offer, I'd take it, but maybe I'm a bit biased  :D
Title: Re: BBC micro reparation
Post by: Bryce on 14:25, 02 March 24
Quote from: teopl on 21:31, 01 March 24worked great with just replacing caps in PSU... thanks again

I returned BBC to my friend but he wants to sell it to me... I am not sure is this computer any good?

can it be compared to CPC?

I saw there is something called "second processor" and that it could be Z80... does anyone knows something about this?

It depends on what you want to do with it. As far as games are concerned, it's nowhere close to the CPC. But if you want to expand it or make your own hardware expansions for it, it not only beats the CPC, but pretty much every other 8-Bit computer around.

Bryce.
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