Ok, let's start. We'll demonstrate usage of Hakko 470 Professional Desoldering Station in this pictorial.
Probably the toughest job in all of pinball desoldering land would be replacing the ASIC chip socket on the WPC CPU board. Well, we figured
if we're demonstrating the best tool for the job, might as well demonstrate it doing the most screwup prone, delicate and toughest job to
begin with... As you can see, the ASIC chip socket has been damaged. There is no point of "repairing" anything here, the socket is gone and
useless, and the CPU will never boot. What we're doing is a straight socket replacement.
Bird's Eye view of the board. There are other components here that need attention, most notably it needs a new battery holder. Another point
of note. A lot of CPU boards DO NOT have chips that control the switch matrix socketed. It was a big problem, with phantom switch
closures (pressing 1 switch triggers 2, 3 or more of them at the same time further confusing the game).
Williams recognized the problem, and started socketing U20 location chip around 1994, I believe. Still, all U20s before that are not socketed,
and they damage easily. When doing repairs, we usually just socket the hell out of the board, and move on with our lives.
That way, when the game is sold, it's a simple task or taking the fried chip out of the socket, and sticking in a new one (Homer Simpson's
voice: "Ummmm... fried chips..."). Chips at U14, U17, U18, U19 and U20 are very damage prone and socketing takes care of that problem
permanently for that particular board. WPC CPU boards sell used for approx. 300$, so it's a wise investment to do it properly.
Let's power up the station. Hakko recommends to heat it up for 3 minutes, but it's actually much less, like 45 seconds to a minute or so. It
requires minimal maintenance and upkeep. It DOES NOT need shop compressor/air. That is built into the station, making it a
self-sustained unit. Another sort of nice feature is the heat cut-off. If the station detects it is not being used for an hour, just sitting there
dissipating heat, it will automatically shut off. I've found that feature to work spotty, not as reliably as Weller® soldering stations, so
when you're done with your work, just turn it off and let it cool.
Let's see what's the bottom of the socket looks like. There is a lot of leads to desolder there, and with such parts (the whole board, sockets,
new ASICs) being somewhat scarce and expensive - cheap, stupid tools like soldapullt, rubber bulb pump, braid etc, simply CANNOT do jobs
such as these. These tools should not be used on delicate board work, they are simply not good enough and they WILL sooner or later do
more damage then good in the long run.
There are friggin' 84 small pins with tiny leads soldered here, in a double row! It took me all of 4 minutes to do this complete job. Of course, I
realize a lot of people cannot afford to buy a desoldering station and simply have to resort to using braid, solldapullt etc... Fine, that is
understandable, especially if you have one or 2 machines and need to do just a bit of work. Please be careful. Alternatively, the easiest way
is to just send your faulty/non-working boards to a reputable business who will fix it all for you at a very reasonable cost. Clive with Coin-Op Cauldron is one of the best and you can send your boards to him with
confidence.
When using those tools, the results are such that you cannot repair the same problem more than once, at most twice, so keep that in mind.
These things, especially solldapullit are very limited in scope of what they can really do, and they are not very precise. After all is said and
done, you end up with a hacked, rigged board and it may prove more expensive to send it out for a "real" repair.
Well, then, what things CAN then these cheapo tools do? Well, I guess, those could be used if you're changing a bridge rectifier or a
big GI male header connector or other IDC connectors around the board (plated through holes are much bigger on such devices than these
pictured here, and the traces coming and going to them are really enormous). So, the board will be "somewhat forgiving" and tolerating to a
certain extent in those areas.
I must add, "if you MUST use those, use them, but, in my opinion they are worth exactly what you paid for, often less, as you now have
destroyed board to show for it. Please, be careful, as using such inferior tools is really time consuming and very slow, patient and precise
job.
So, how EXACTLY those tools hack and destroy the boards? In my opinion, they are simply not adequate and the worst offenders
when it comes to lifting traces of the board. Take a look at the above picture. Notice many VERY SMALL traces coming in and going out from
the board? That's what gets destroyed, lifted, broken etc... When that happens to you, all you can do is get a piece of wire and perform
"jumpering" fix. That is soldering the wire to ends of the trace thereby the connection remains there.
Anyways, in approximately as long as it took you to read this a couple of sentences here, the first double row of the socket is done.
Closeup of the first rows being done. Clean cut, professional solder lifting job. That's what we want and that's the end goal.
Another closeup picture. The size of the picture might deceive you, these through plated holes are quite small.
The whole thing is done and gone. Out of the board and on its way to the trash bin!
Closeup of the whole thing. If you've ever wondered what does bottom of the ASIC socket looks like, here is your exclusive view. Wow, dude,
so THAT's what the bottom of the socket looks like, I'll be darned... Maaan, that's so faaaar out! Umm, yeah.
Keep in mind that we are not taking out the socket and we're done with it, that is only first half of the job. We are REPLACING the
crappy/damaged one with the new one. In order to do that, we have to have everything ready for the new socket and the delicate job of
soldering it in. Now, that is a job.
Here you go, Hakko 470 Desoldering Station did this without breaking a sweat 8 minutes after I pressed the power button on it... So, like,
when is that big & delicate ASIC socket desoldering job gonna start?
Last parting shot, that's it. This station is really the Big Kahuna of desoldering. Now... another tricky and precise job will be to put that new
socket in and test the board for continuity, then we'll put it first on the bench, like in this pictorial, then
we'll test it and power it the actual game. That's it for now!
I received some emails asking about to demonstrate something else besides removing ASIC chip socket (as most will never have to go
through that). Sure, how about removing fried and faulty U20 chip off of WPC Cpu game and get it ready for installing a socket? These chips
are notorious for dying on you if something shorts in the game related to switch matrix. Williams was aware of the problem and recognized it
by installing sockets on all WPC CPU boards after 1994. Here goes a 3 minute job...
Here is the board. U20 is in the middle underneath the battery holder. Let's fire up the station...
Here is the board on the traces side. There is a lot of small traces coming and going into this chip and you really do need a quality tool
unless you want to torch and hack the board. Let's get going...
After a minute or so of desoldering, here we go, almost done.
Done, with a closeup picture. Remember, these plated through holes are quite small, this picture was taken with an extreme closeup.
Done, view from the component side. Clean up a little, install socket, solder it in, install fresh chip and move on with your life.
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If you do any kind of circuit board work, you need something better that crappy 6$ plastic Radio Shack toy that will
destroy your boards. Here is one of the best, if not THE best tool on the market for great desoldering jobs today. This great desoldering
station makes it look too easy , and in fact when using it, it is... it is manufactured by an established company, 