Spring Cleaning the Motherboard

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dhoggan
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Spring Cleaning the Motherboard

Post by dhoggan » Tue Jul 31, 2018 6:16 pm

Having just recently picked up a second Beeb Model B - I’ve noticed a couple of commonalities in their condition. The obvious one if that the cases have yellowed over the years and after reading around on *. I see that treatments (retrobrite or Jerome Russell Bblonde seems to give give results), so I’ll be off to try them shortly.

The other thing I’ve noticed is that the motherboards are a bit shabby-looking. Especially around the jumper pins where there is a white ‘growth’ for wont of better description. Whilst the Beeb still works, it cannot be a good thing to have contaminants on the motherboard and so I’m considering cleaning it. Problem is: I have no idea how to.

I’ve seen posts across the forums talking about using vinegar and water, but I’ve found nothing that actually lays out a procedure for how to safely clean up the motherboard. I would have thought just IPA and a soft brush, but seeing mention of vinegar makes me wonder if IPA is a bad thing.

Has anyone any advice on how to clean a mobo they can share, or is this something an online service can offer?

Thanks,

Dave
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Elminster
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Re: Spring Cleaning the Motherboard

Post by Elminster » Tue Jul 31, 2018 6:22 pm

Depends what caused it. Vinegar is generally used for battery or capacitor leaks. Usually IPA is good enough for most other things. Pcb and contact cleaner work as well.

Some people put them through the dishwasher but I never done that. Have to be careful it has dried proper and nothing is falling off.

I don’t retrobrite, just foam cleaner, soap and water etc. But if you want to restore colour then yes, although it will gradually go yellow again, but could be decades depending on how much sun it gets.

VincentVega
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Re: Spring Cleaning the Motherboard

Post by VincentVega » Tue Jul 31, 2018 6:52 pm

On the last Beeb I bought, I used a brush (an ancient one from a hoover) to get rid of the loose dust and gunk from the motherboard and then splashed distilled water (originally bought from an car parts shop) all over it. Once it looked nice and clean again, I poured IPA over the board, left it in the sun to dry for a few hours and then popped it in the airing cupboard for a couple of days. I was a bit apprehensive as this was the first time I'd deliberately let liquids get anywhere near my computers, but the board came up very well and the computer works perfectly.

With the cases, I usually press the bath into service and use a combination of Cif (Jif) and anti-bacterial cleaner to clean up any grime with a non-abrasive sponge and a warm stream of water from the shower head. I've had mixed results with Retrobriting - the floppy drive case came out very well, whilst my Master has a rather unlovely speckled effect.

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daveejhitchins
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Re: Spring Cleaning the Motherboard

Post by daveejhitchins » Tue Jul 31, 2018 7:43 pm

Pop it in dishwasher - dry in the oven @ 60C for an hour - job done . . . If you’re worried about any labels, on the PCB, remove first (use hair drier, if needed) then re-attach.

Dave H :D

dhoggan
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Re: Spring Cleaning the Motherboard

Post by dhoggan » Tue Jul 31, 2018 7:53 pm

Oh, OK. There doesn't appear to be any leakage so I’ll give the vinegar a miss, but I’ll give the IPA a go. Do you normally desocket the ICs or leave them in?

As for the case, I am tempted by the Bblonde, simply as getting hold of retrobrite will be a bit of a pain in the UK.

Thanks,

Dave
BBC Model B Issue 7 - MMC Card implant; SCART-to-HDMI convertor.
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danielj
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Re: Spring Cleaning the Motherboard

Post by danielj » Tue Jul 31, 2018 8:12 pm

Retrobrite is something that's hand mixed - bblonde is just easier. There's a good set of threads about it on Amibay if I remember :)

Remove anything that can be removed before attacking the motherboard.

At the risk of teaching people to suck eggs (apologies if I am): If you're not comfortable removing ICs etc, do think before you do it as you can end up in a world of pain with bent/broken pins and dodgy sockets. A good going over with an ESD safe brush can get rid of the worst of things. I don't think I've ever bothered cleaning a motherboard beyond that unless it's suffered a battery leak. I've never noticed the stuff around the jumpers causing any problems.

d.
Last edited by danielj on Tue Jul 31, 2018 8:13 pm, edited 2 times in total.

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Elminster
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Re: Spring Cleaning the Motherboard

Post by Elminster » Tue Jul 31, 2018 9:32 pm

And also dont forget to photo and document whre al the bits you took off came from. Or you will be putting it back together forever, or at least peering at other peoples hi-res photos on the interweb trying to workout where part X came from and why you have 10 bits left over.

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Elminster
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Re: Spring Cleaning the Motherboard

Post by Elminster » Tue Jul 31, 2018 9:34 pm

danielj wrote:
Tue Jul 31, 2018 8:12 pm
Retrobrite is something that's hand mixed - bblonde is just easier. There's a good set of threads about it on Amibay if I remember :)
8 bit guy youtube channel has loads of cleaning vids including retrobriting. Some of his techniques I am not hundred percent convinced by but the rerobrite and general clenaing ones seem fine.

dhoggan
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Re: Spring Cleaning the Motherboard

Post by dhoggan » Wed Aug 01, 2018 10:57 am

Thanks for all the advice - very useful. I think I’ll be looking at buying a DIL insetion tool from somewhere just to avoid any tears.

Just been watching one of the 8 Bit Guy video (and thanks for recommending that!) on comparing bleaching techniques so off to buy some 40 vol peroxide as we seem to have the weather for it. For those of you who have bleached the Beebs case, do you take the brown/black keyboard surround off first?

Thanks,

Dave
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BBC Model B Issue 2 - needs some refurbishing, but don't know where to start.
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VectorEyes
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Re: Spring Cleaning the Motherboard

Post by VectorEyes » Wed Aug 01, 2018 11:44 am

I've never done it, but I can't help feeling that if you're mixing something that's brown/black with bleach, the brown/black item isn't going to stay that colour for long!

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danielj
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Re: Spring Cleaning the Motherboard

Post by danielj » Wed Aug 01, 2018 11:47 am

dhoggan wrote:
Wed Aug 01, 2018 10:57 am
Thanks for all the advice - very useful. I think I’ll be looking at buying a DIL insetion tool from somewhere just to avoid any tears.
These have a tendency to cause more tears! Best to use a screwdriver or L-shaped piece of metal to gently prise up one end then the other a little at a time. When you use one of the commonly available tools the whole thing gives at once, pings out, bent pins abound...

d.

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1024MAK
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Re: Spring Cleaning the Motherboard

Post by 1024MAK » Wed Aug 01, 2018 11:52 am

Be careful, DIL insetion tools are not infallible. The cheap extraction tools are even worse.

DIL Chip Fitting and Removal
DIL IC Fitting, DIL IC Removal

New DIL chips nearly always have their pins splayed out at a slight angle, so that when compared to the spacing on the socket, the two rows of pins on the chip are wider compared to the socket (or the holes on the PCB). Chips that have been inserted with tools (either manually or by robots) can retain the same springiness when removed from sockets, so the pins on these may splay out as well.

So before placing a chip into a socket (or the PCB holes), the pins have to be pushed into alignment. There are a number of ways of doing this. One is to buy suitable special tools.

The second is the way I do it. First, take anti-static precautions. Throughout, try not to touch the metal pins with your fingers. Firstly we don't want oil from your skin on them, and secondly in the event that you do get a static charge on you, it could transfer to the chip via touching one or more pins. But if you do accidentally touch a pin, please don't panic. As long as you have taken basic anti-static precautions, the chip most likely will be fine :D

For large 24, 28, 32, 40 pin etc. DIL chips, you may not need long noise pliers, for the smaller sizes, you will need them. Grab an old newspaper, notebook or any other wad of scrap paper. Put this down on your table/bench/worktop to protect it. It should be at least ten pages for newspaper paper, or five for 80g/90g/100g paper. Pick up the chip by it's plastic or ceramic body (screwdrivers and/or pliers help here) and get a good grip in the middle of the body. Turn it so that one row of pins are flat against the paper covered table/bench/worktop, with the body at right angles to the table/bench/worktop. Now press down the pins onto the paper while rocking the chip back and forth a bit so that the pins move intowards the body a bit. Repeat with the other row of pins. Check against the socket, repeat again until the pins line up nicely with the socket.

Once the pins are aligned, double check each pin, then apply even pressure to the top of the chip and push it into the socket, starting gently at first while you check the pins to see if any are bending in or out of the socket. Once you are sure that each and every pin is going where it should be, press hard on the chip so that it goes fully into the socket. The PCB should be on a flat surface so it is properly supported. If the PCB is not in a case, you may want to put something down to protect the table/bench/worktop from the component legs.

But of course, before you fit chips, chips have to be removed. The trouble with the two pronged removal tools, is that chips really don't like being removed from the sockets. They fight and resist. But once the pins do start coming out, the friction releases very quickly. So quickly that the chip turns in it's socket as it comes out and the last set of pins either gets horriblely bent or worse, break off :twisted:

So you have to slowly ease the chip out by alternatively working at each end. I normally use a suitable screwdriver, but a rounded, blunt flat knife is favoured by some. The best tool being a piece of flat metal with a sharp right angle bend near the end (this can get in tight spaces). Whatever you use, never use the tool against the top of the PCB. You are likely to damage the copper tracks. Always lever between the plastic socket and the underside of the body of the chip. Lever the chip up by about 1 to 2 mm at one end. Keep a finger gently pressing on top of the end of the chip at the end you are working on, just in case it springs up faster than you want/expect. Then repeat at the other end. Then at the first end, repeat again, but lift a little higher, then again at the other end. Keep going until you feel the chip release all it's pins from the socket. You can now lift it up with your fingers (at the ends of the body) with no force whatsoever :D

Have fun :D

Mark
Last edited by 1024MAK on Wed Aug 01, 2018 12:01 pm, edited 2 times in total.

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Elminster
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Re: Spring Cleaning the Motherboard

Post by Elminster » Wed Aug 01, 2018 10:25 pm

danielj wrote:
Wed Aug 01, 2018 11:47 am
dhoggan wrote:
Wed Aug 01, 2018 10:57 am
Thanks for all the advice - very useful. I think I’ll be looking at buying a DIL insetion tool from somewhere just to avoid any tears.
These have a tendency to cause more tears! Best to use a screwdriver or L-shaped piece of metal to gently prise up one end then the other a little at a time. When you use one of the commonly available tools the whole thing gives at once, pings out, bent pins abound...

d.
He did say insertion, not extraction, but then Mark has done an essay.

I sometime use the insertion tools, and sometimes not, depends on ease of access.

Extraction my new best friend is the splurge kit but sometimes screw driver, again depends on access.

Do we have a pinned post on this anywhere or a pin faq pointing to such things. Comes up a lot recently.

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danielj
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Re: Spring Cleaning the Motherboard

Post by danielj » Thu Aug 02, 2018 6:29 am

Given the scarcity of insertion tools and the relative ubiquity of extraction tools, I think it was fairly safe to assume that extraction was what was meant. I am, however prepared to be corrected by the original poster :)

dhoggan
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Re: Spring Cleaning the Motherboard

Post by dhoggan » Thu Aug 02, 2018 5:46 pm

I has assumed that the insertion and extraction tools were the same, but since the recommendation is to gently pry them out from alternating ends, I'll be going for that approach.

No I'm back home I can start looking at how best to disassemble the Beeb and see how best to disassemble the case and strip down the mobo. Advices about the brown keyboard frame ad peroxide likely not being a good idea taken so I'll hunt around and see if there are other threads on other people's adventures - after all freshening up the case is probably well covered here on Amibay etc.

If I can work out an easy way to get pictures uploaded I'll add a few of the process :-)

Thanks,

Dave
BBC Model B Issue 7 - MMC Card implant; SCART-to-HDMI convertor.
Retroclinic RPi CoPro

BBC Model B Issue 2 - needs some refurbishing, but don't know where to start.
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Elminster
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Re: Spring Cleaning the Motherboard

Post by Elminster » Thu Aug 02, 2018 10:23 pm

dhoggan wrote:
Thu Aug 02, 2018 5:46 pm
I has assumed that the insertion and extraction tools were the same,
Only in the same way you can use a crowbar (pry bar) as a hammer.

Best not to use either of those in this context though.

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Re: Spring Cleaning the Motherboard

Post by VectorEyes » Thu Aug 02, 2018 11:09 pm

Elminster wrote:
Thu Aug 02, 2018 10:23 pm
dhoggan wrote:
Thu Aug 02, 2018 5:46 pm
I has assumed that the insertion and extraction tools were the same,
Only in the same way you can use a crowbar (pry bar) as a hammer.

Best not to use either of those in this context though.
I don't know, I had an awful lot of difficulty getting a 6502 into a RAM/ROM expansion board last week... :)

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1024MAK
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Re: Spring Cleaning the Motherboard

Post by 1024MAK » Thu Aug 02, 2018 11:35 pm

There are tools known as pin straighteners, I think I have one somewhere (not seen daylight for about 20 years mind...), they can be useful if you are regularly fitting chips.

But they only straighten the pins. You then fit the chip yourself.

Mark

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Re: Spring Cleaning the Motherboard

Post by sbadger » Sun Aug 05, 2018 12:36 pm

1024MAK wrote:
Thu Aug 02, 2018 11:35 pm
There are tools known as pin straighteners, I think I have one somewhere (not seen daylight for about 20 years mind...), they can be useful if you are regularly fitting chips.

But they only straighten the pins. You then fit the chip yourself.

Mark
I picked one of these up a couple of weeks ago while socketing up a C64 mobo, it was one of the cheap ones, about a fiver, but actually pretty good. Much better than pliers etc.
So many projects, so little time...

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