Acorn Electron problem flashing picture and lines

[traindriver69]

Hi all
Now got my plus 3 sorted need to fix my electron everything works but just on the screen I get like interference with flashing lines like someone is moving a loose areial lead around I get through rf and video not tried rgb as I dont have a lead.
sometimes it stops for a few secs then goes like mad .
any help please.

[traindriver69]

Hi all
Heres a quick video atachment of what it is doing any help please.

[Kazzie]

From the video footage, I'd agree that it looks like a poor connection in the RF cable, or at one of the ends.

Have you tried the Electron and lead with another TV? If there's no change, I'd suggest trying a replacement lead.

[traindriver69]

Hi
problem is I get the same through the video connection with a phono lead.

[mark71]

Hi
problem is I get the same through the video connection with a phono lead.

Have you tried a RGB to Scart lead?

[roland]

Did you already clean the pins of the ULA? That is a common component for both video and UHF output.

[traindriver69]

Hi
no I have not what is the best way of doing it do I just clean the pins where it is or do I have to remove the ula and clean the lot.

[daveejhitchins]

Hi
no I have not what is the best way of doing it do I just clean the pins where it is or do I have to remove the ula and clean the lot.

You can only do this if your ULA is in a socket (Issue 6 boards are a different type of ULA build!).

So, assuming you have a socketed ULA then you need to remove the clip that hold the ULA in place. There are two main ULA sockets - the more common socket is easier and is more likely to suffer broken pins. If you are unsure post a photo and better guidance can be given!

Once you have removed the retaining clip - remove the ULA and clean the pins carefully with IPA on a cotton bud (don't leave cotton in there!) or a small brush. You can also clean the gold contacts of the ULA with IPA and cotton bud.

Replace retaining lid. Then, while you're in there . . . Remove the whole PCB and clean the rear edge connector - this won't fix your current problem, however, will reduce any future issues!

Dave H

[traindriver69]

Hi
This is what I have

[jms2]

That’s an issue 4. You need to ease the metal clip thing off, after which the ULA simply lifts out. Take care with the pins, they are tiny springs and so you don’t want to snag them with cotton wool. Personally I’d only clean the flat pads under the ULA itself.

[daveejhitchins]

Hi
This is what I haveIMG_20200710_124212.jpg

If you can't figure out how to release the clamp, do let us know and I'll do a few photos.

Dave H

[dixiestoat]

I thought that ULA was only on Issue 2, and Issue 4's had the Metal Top Springy Clip... for want of a better description.. Obviously not..!

[traindriver69]

Hi
If you could supply some pics just to be sure that would be brilliant I have only got the one electron and don't want to cock it up.

[jms2]

I plan to open up my issue 4 hopefully this weekend to clean the ULA pads so if there are no existing pictures I will post some.

[daveejhitchins]

Hi
If you could supply some pics just to be sure that would be brilliant I have only got the one electron and don't want to cock it up.

I'll get some photos for you tomorrow . . .

Dave H

[traindriver69]

Hi
Any chance of some pics on removing the ULA please don't really want to cause any damage to it.
Many Thanks

[jms2]

Sorry I haven’t had a chance to get mine apart yet. Not forgotten though.

[jms2]

OK, done it now, here are some pictures:

First thing to note is that the hold-down clip is different on yours compared to mine. However the socket looks the same, so I think the same basic principles should apply. The H shaped clip is spring-loaded and has four legs which hook under the four corners.

The basic technique is to use something sharp to get behind each leg, and while pushing down to unhook it underneath, push gently outwards and then release the downwards pressure. This allows it to unhook.

Here are two legs unhooked.

At this point you can ease up one side but you still need to undertake the unhooking process for the other side.

Unhooking the other side:

This is the clip removed:

At this point there is nothing holding the ULA down other than gravity:

You can simply lift it out, don't worry about putting it back the wrong way because its keyed:

This is the inside of the socket. All the little contacts are spring loaded.

[jms2]

This is the underside of the ULA showing the pads. They are not vulnerable at all (no spring loading here):

I would suggest gently scraping the tops of the socket contacts with a metal object, rather than touch them with a cotton bud. I guess you could wipe them with a piece of paper soaked in IPA (not India Pale Ale!):

Here's the IPA/paper technique used on the ULA contacts. You can "scrub" a bit.

When putting the clip back, the front side has special "ramps" to aid in pressing down the clip. So you need to hook on the back side first.

Then press down the front. It's easier to do one corner at a time.

[traindriver69]

Hi
That is brilliant and well described many thanks will let you know how I get on.

[jms2]

I have never found any actual "dirt" on mine!

At the moment the keyboard is doing odd things, and it's not a keyswitch issue, so I think it must be down to the ULA. I cleaned it about a year ago and the problem went away, so I think I need to do it again.

[jms2]

My latest cleaning operation seems to have been successful - keyboard is now working nicely again!

[traindriver69]

Hi all
I have taken the ULA out this morning and gave it a clean and now no more flashing screen brilliant many many thanks for your help.

[jms2]

Wow, I have to say that I was slightly doubtful that it would fix the problem, so it's great to hear that it did. My doubt came from the fact that I don't recall anyone else having a similar problem in the past.

Out of interest, did you find any visible dirt?

[traindriver69]

Hi
no it looked fine I wonder if the ULA just wanted reseating.

[Kazzie]

Quite possible. Either way, the problem's gone.

[daveejhitchins]

Thanks for stepping-in, John - I've had a rather busy weekend.

Dave H