Test Equipment Anonymous (TEA) group therapy thread

[mnementh]

So... what machine are you trying to restore to its former glory with all this very industrious work?

mnem
 

[Mr. Scram]

and hiding under the solder mask. Nasty.

Obviously the first step is to remove the affected components and neutralize the caustic ...

I usually use 25% vinegar acid and wait until the bubbling stops (which is an indication of the reaction having finished).
When done, the pcb goes into the ultrasonic. Solder mask is removed with a fiberglass pen, any caustic that has crept under the solder mask can be discovered and any hidden corrosion can be removed.

Then it's repairing traces and redoing those little through holes and the contacts ...
A Bungard press is great for that.

After several hours of work the board was back in operations ...

Tools used: scalpel, fiberglass pen, soldering iron and desoldering station, ultrasonic, neutralizing agent (vinegar acid), compressed air, very fine copper wire, bungard press, DMM (for continuity checks), Oscilloscope (for checking the signals at the probe points and I/Os)

I'm always a bit worried about not getting it all. Looks like you did a thorough job though. Nicely done. What was the board out of?

[med6753]

I wake up to see that cooler heads have prevailed and we all agree:

Covid discussions: NO
Political tirades: NO

If these subjects rear their ugly heads again I will no longer participate in this thread. And that's not a threat. 

Bd....I got plenty of coffee. 

I love you man. I really do. But if you and Oculus are going to start being fucking topic nazis and threaten to ragequit every time a topic comes up, then please, don't let the screen door hit ya on yer way out.

Seriously. You've both turned into prickly bastards, getting your hackles up any time anything even remotely topical comes up; I'm tired of walking on eggshells. You are being too easily bothered, and that's the short of it.

Now either put on yer big boy pants and deal, or have some popcorn & TEA.

mnem
 

And my measured response to this is bullshit. You know, it's not the subject matter so much that I object to, it's the attitude that goes along with it. You act like a bully. That this forum is for your personal use to trash with tirades as you please and openly ridicule anyone who disagrees with you. And your response here to me and Oculus proves it. I got news for you. Who died and left you boss?

Yes I'm a prickly bastard and proud of it. And I really don't like individuals who truly believe they are always right. And unfortunately that's how you come across. You feel like you walk on egg shells? What a load of crap.  More like a bull in a china shop.   

I got my big boy pants on. As well as my walking shoes. And I'm voting with them. 

[Specmaster]

Edit: fuck, have run out of coffee  . Monday sucks so far.

To misquote Lady Bracknell:

“Running out of tea, Mr. BD139, may be regarded as a misfortune; to run out of coffee looks like carelessness.”

I have plenty of coffee too.

[Specmaster]

... because I have zero interest in explosives, ...

Coo, somebody must have had a dull childhood! 

Quite the reverse in reality, I was pulling things to bits a and learning how they worked and putting them back together again, well some them at least 

[Saskia]

that board is a Williams pinball CPU (WPC89) with the infamous 84 pin ASIC which does most of the bus access control ...

@med6753  I am sorry I brought up some stuff that was really weighing me down. Which is why I am focusing on more constructive stuff right now ...

[Mr. Scram]

that board is a Williams pinball CPU (WPC89) with the infamous 84 pin ASIC which does most of the bus access control ...

@med6753  I am sorry I brought up some stuff that was really weighing me down. Which is why I am focusing on more constructive stuff right now ...

When I Google search that board the first few hit are about repairs. 

I get what other people are saying but this should be the one thread people can vent things that weigh on their minds. I did play my part in where it ended up and guess I should have left that in another thread.

[Saskia]

well, it's not surprising that boards in pinballs that are sitting somewhere to earn money with as little maintenance as possible do break.
unfortunately repairing them is a major pain.

[mnementh]

And my measured response to this is bullshit. You know, it's not the subject matter so much that I object to, it's the attitude that goes along with it. You act like a bully. That this forum is for your personal use to trash with tirades as you please and openly ridicule anyone who disagrees with you. And your response here to me and Oculus proves it. I got news for you. Who died and left you boss?

Yes I'm a prickly bastard and proud of it. And I really don't like individuals who truly believe they are always right. And unfortunately that's how you come across. You feel like you walk on egg shells? What a load of crap.  More like a bull in a china shop.   

I got my big boy pants on. As well as my walking shoes. And I'm voting with them. 

My measured response is this: You are right now exemplifying the kind of behavior you are talking about. Whether this is projection or you just don't see it, I don't know. But I work very hard to self-regulate, and I've carefully reviewed everything I've posted in here in the last 2 days. You are the one acting like a bully, and I'm not having it.

Cheers,

mnem
*no further comment*

[WastelandTek]

so Mnem

when did you lose the capacity for self doubt?

[mnementh]

well, it's not surprising that boards in pinballs that are sitting somewhere to earn money with as little maintenance as possible do break.unfortunately repairing them is a major pain.

So which machine is it for...? Or have all the labels rotted off and you won't know what it is until you resurrect it and can read all the ROMs?

mnem
*trying to remain on-topic*

[Saskia]

any WPC89. The roms are interchangeable. This will run in a Funhouse, Addams Family, Hurricane, Fish Tales, Star Trek TNG, and several other Bally and Midway WPC 89 machines.

[Mr. Scram]

well, it's not surprising that boards in pinballs that are sitting somewhere to earn money with as little maintenance as possible do break.
unfortunately repairing them is a major pain.

Is there anything specific that makes such a pain? The often unintentional maintainability or lack thereof of any given PCB is always an interesting one.

[mnementh]

so Mnem when did you lose the capacity for self doubt?

Not lost. Carefully curated against constant self-review with as much skepticism as I can muster. In most cases, that skepticism is so caustic it would make an outside observer shudder.

mnem
Your conscience is the measure of the honesty of your selfishness. Listen to it closely.

[Saskia]

yes, the way pinball operators try to keep the machines up and running with absolut zero maintenance and zero downtime, which basically leads to burned connectors (they strip the wires and solder them directly to the PCBs) and battery issues that are left untreated until the entire board disintegrates. This basically turns a 10 minute job into a multi hour enterprise.

[mnementh]

any WPC89. The roms are interchangeable. This will run in a Funhouse, Addams Family, Hurricane, Fish Tales, Star Trek TNG, and several other Bally and Midway WPC 89 machines.

Well, no... I know enough to know that much. I guess I operated under the assumption that the software on the board is as valuable as the board itself, as they are both tied to ownership of the software and indeed, the pinball machine they operate? Otherwise, wouldn't repopulating any of the reverse-engineered boards be functionally a better solution than trying to save this poor, abused subject?

Or is your interest more the pure TEA aspect, of restoring THIS EXAMPLE to its former glory?

mnem
*war stories*

[Cerebus]

corrosion here, corrosion there, corrosion everywhere ...

If anybody out there is, now or at any time in the future, designing something that needs an auxiliary battery "on board", please, please, please, consider relocating it to a little plastic container off the board and connecting to it with a little plug and socket. Yes, it'll add 50¢ to your BOM, but it will save your customers $$$ or €€€ in the long run when the battery eventually craps out. If you're feeling really considerate you could make that container leak proof, but at least put it at the bottom of the case (gravity wise).

[mnementh]

Sadly, many would consider that kind of consideration to be contrary to their job security. 

mnem
 

[mnementh]

OMG... I just looked up Fish Tales on pinside... I don't believe I've ever seen it before; or if I did, I mental blocked it. 

Surprising, as I grew up a stone's throw from 3 different bucolic sh... uhh... watering holes that would have to have been the target demographic. How in the hell did it get past concept...? Is the gameplay really THAT good?

mnem
 

[Saskia]

yes. it's got the best video mode by far, is fast, fun and family friendly. A very great pinball. absolutely. Mine is currently awaiting restoration, however it's sitting in an industrial complex which currently is under lockdown 

[Specmaster]

yes, the way pinball operators try to keep the machines up and running with absolut zero maintenance and zero downtime, which basically leads to burned connectors (they strip the wires and solder them directly to the PCBs) and battery issues that are left untreated until the entire board disintegrates. This basically turns a 10 minute job into a multi hour enterprise.

Which must really cost them more in the long run. Perhaps the operators don't any skilled engineers because they think they will eat into their profits by employing them and are happy to replace a machine in the end rather than pay an engineer to repair them?

[mnementh]

yes. it's got the best video mode by far, is fast, fun and family friendly. A very great pinball. absolutely. Mine is currently awaiting restoration, however it's sitting in an industrial complex which currently is under lockdown 

*nods knowingly* 

mnem
Keep the Faith.

[Specmaster]

corrosion here, corrosion there, corrosion everywhere ...

If anybody out there is, now or at any time in the future, designing something that needs an auxiliary battery "on board", please, please, please, consider relocating it to a little plastic container off the board and connecting to it with a little plug and socket. Yes, it'll add 50¢ to your BOM, but it will save your customers $$$ or €€€ in the long run when the battery eventually craps out. If you're feeling really considerate you could make that container leak proof, but at least put it at the bottom of the case (gravity wise).

Manufacturers just really don't care, they make more money by selling you a replacement board or better still a new machine.

[drussell]

If anybody out there is, now or at any time in the future, designing something that needs an auxiliary battery "on board", please, please, please, consider relocating it to a little plastic container off the board and connecting to it with a little plug and socket. Yes, it'll add 50¢ to your BOM, but it will save your customers $$$ or €€€ in the long run when the battery eventually craps out. If you're feeling really considerate you could make that container leak proof, but at least put it at the bottom of the case (gravity wise).

Unfortunately, extended product lifetime and durability are rarely even remotely driving factors of design in most cases these days.

Often, the opposite is (intentionally) true.  If you build a version of product X that lasts virtually forever, you can only sell so many product Xs before the market is essentially permanently saturated.  Most products (seemingly, often even professional and industrial gear these days,) are designed with some measure of obsolescence essentially built-in, one way or another.  Batteries that are difficult to nigh on impossible to change due to permanent adhesives holding things together, not caring about sealing things from the elements or preventing corrosion (like buried bad backup battery time-bombs,) or the (really most insidious of them all lately,) software kill-switch and phone-home-on-startup for virtually everything these days, including the dang toaster....   

... but I digress ...

[xrunner]

CPAP machine anyone?

My neighbor got a new CPAP (continuous positive airway pressure) machine and the supplier said to throw this one away. He asked me if I wanted to play around with the old one (he knows me pretty well). Of course I do. It's a ResMed unit and the PCB says Sydney, Australia.

So what it does is give you positive air pressure in your airway all night. It has a control unit which has an SD card. The SD card appeared to have daily files on it giving the prescriber the data on the performance. In the control unit is a blower. The left side connects to the right side which has a water reservoir for humidity control. Then the air comes out a long tube to your mask.

The main unit has a menu system for some simple user settings, but there is no way to control the air pressure in the menu. He said they can do it in the office if needed after a sleep study. There is an interface connector on the back but not one I recognize. I presume that is where they connect an external computer or proprietary unit to set it up.

Some of the parts used, other than the usual suspects such as voltage regulators and the like -

stm32f103zgt6
ARM® Cortex®-M3 STM32F1 Microcontroller IC 32-Bit 72MHz 1MB (1M x FLASH

Sensiron sdp711-01 differential pressure sensor

GE NPA-C02035 Surface-Mount Pressure Sensor

On the top side of the PCB are a whole lot of gold pads, perhaps for testing? In the water reservoir unit is a humidity sensor that sends it's data back through the interconnect between units.

Right now it blows a steady stream of air and doesn't require the humidity unit to run. Might be useful for a project someday.