Faulty Electron

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Garrettimus
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Faulty Electron

Post by Garrettimus » Mon Jul 31, 2017 10:06 am

Dear friends,

Out of the blue, my Electron started to behave erratically. Whenever I touch any of the keys marked in the photo, the Electron crashes/freezes. Other than that, it works properly - and even run games from David's MGC multicart.

Any ideias of what might have happened? Like I said, the problem started out of the blue, it was sitting on my table ever since I started using it again recently (it had been on storage for a while). #-o :cry:

Thank you very very much!
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duikkie
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Re: Faulty Electron

Post by duikkie » Mon Jul 31, 2017 10:21 am

not that i know the electron, but looks like keyboard cable ? or raster chip ?

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daveejhitchins
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Re: Faulty Electron

Post by daveejhitchins » Mon Jul 31, 2017 10:45 am

Hi, Marcus . . .

The first thing to try is to:
Open-up - unplug the keyboard - you may find some white powdery 'stuff' - you can remove this with an old toothbrush - it doesn't seem to cause any problems, however. Reconnect and test.
Still faulty? . . . Remove the ULA - depending on the type of ULA: Type 1 just has a small bar holding the ULA cover on. This can be removed/replaced with your fingers/thumbs. - Type 2 requires a very small screwdriver to leaver the springy legs off. you only need to spring-off the two nearest the front, then the back two should just wiggle off. When replacing - latch the back two legs before pushing home the front two legs. Type 3 is fitted to later electrons and can't easily be removed, however, as it's not in a socket it shouldn't be causing your issues! - Once you have the ULA exposed - remove and clean the contacts of the socket and the ULA with a cotton bud soaked in IPA. Then replace ULA. Note: When replacing the ULA it only fits ONE WAY! Note that one corner of the ULA is different from the other three and note that the socket corners are different. The corner of the ULA the doesn't have a notch in it goes to the back left hand side of the socket - carefully fit the ULA, ensuring it's seated correctly before replacing the lid!
Still faulty? . . . Is your ROM (28pins), the one to the left of the 6502 (40pins) in a socket? If it is then remove and replace - just to clean the socket.
Still faulty? . . . Remove the keyboard, again, and carefully check the ribbon cable for continuity - you'll need a multimeter, ideally, for this task! Try and borrow one or buy a really cheap one to do the testing.

Still faulty? . . . :shock: Oh dear, we need more tools . . .

Let us know how you get on.

Dave H :D
Parts: UM6502CE, GAL22V10D, GAL16V8D, AS6C62256A, TC514400AZ, WD1772, R6522, TMS27C512, AT28C256
Products: ARA II, ARA III, ABR, ATI, AP6, MGC, AP5 . . .
For a price list, contact me at: Retro Hardware AT dave ej hitchins DOT plus DOT com

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Garrettimus
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Re: Faulty Electron

Post by Garrettimus » Mon Jul 31, 2017 11:00 am

Thank you very much, Dave, I'll follow your instructions! :D

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CMcDougall
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Re: Faulty Electron

Post by CMcDougall » Mon Jul 31, 2017 1:28 pm

Bet is a issue 4 or 6 board, if so bin it & take spares, & treat yourself to a bomb proof issue2!!
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