Question about a F18A in combination with a composite mod

[san-d-2000]

A few months ago i bought a F18A and got someone in England to install it for me, the system already had a Yurkie composite mod installed with a mini-jack out, so we decided to keep the composite mod for audio and for the Atari adapter. After a couple of days the F18A stopped working but also the Atari adapter through composite didn't give a signal so i send it back to my man in England and he found out the composite mod had a resistor blown and the F18A had corrosion all over the legs of the chips. So he changed the composite mod for an (in his opinion) better one and he reflow the soldier joints of the chips on the F18A (which i wish he wouldn't had done because this voided the guarantee), after a week the F18A stopped again.

 

Next i contacted the seller in the US told him what happened and send it back, for an extra fee he transplanted all chips to a brand new PCB and replaced the other parts with new ones, after getting it back the F18A worked perfectly for three weeks before it stopped again, i opened up the Colecovision and noticed the corrosion on the F18A was back again, the seller advised me to clean the board with a toothbrush and some Isopropyl Alcohol, so i did after cleaning the board it worked for another week.

 

Now i just cleaned it again and got it running again, but i cant tell for how long, meanwhile i ordered another F18A from another source, but before installing that one i would first like to know what is causing this problem, does anyone here have any thoughts?

Could it be the combination of the F18A and the Composite mod, bad craftsmanship, or something else?

 

Please let me know your thoughts.

 

Edited June 14 by san-d-2000

[+mytek]

12 hours ago, san-d-2000 said:

Now i just cleaned it again and got it running again, but i cant tell for how long, meanwhile i ordered another F18A from another source, but before installing that one i would first like to know what is causing this problem, does anyone here have any thoughts?

Unless you're living in a country plagued by acid rain, there's absolutely no good reason for a new PCB to start corroding unless the manufacturer left something corrosive on the board. So with your alcohol cleaning behind you, there really shouldn't be any more problems with corrosion from this point forward (assuming you did a good job). This does make me wonder why the seller didn't already do this before sending the board to you.

 

12 hours ago, san-d-2000 said:

Could it be the combination of the F18A and the Composite mod, bad craftsmanship, or something else?

It's not the composite mod, so that only leaves the last two possibilities.

[Ruggers Customs]

Yeah I'm with @mytek here.  I've installed many F18a boards into Colecovisions along with TI99/4a computers and I've never experienced anything close to what you're experiencing here.

 

One thing I do differently now is I won't accept any F18a install jobs unless the F18a itself comes directly from Arcade Shopper.  I've ran into too many problems with others making F18a boards (now that the older model is open source) and there always seems to be some sort of an issue.  With Arcade Shopper, Greg is getting his boards directly from Matthew Haggarty who created the F18a.  Working directly with Greg and Matthew always makes things easier if there are issues too.  Plus, 3rd parties generally try to pin the blame on the customer or installer when things go south.  

 

As far as a resistor blowing on the AV mod, whether it was one of the 10k ohm resistors or the 75 ohm resistor, I've never experienced that either.  I've put in hundreds of those too.  So other than some sort of power supply issue, I'm not sure what could have caused that.

Edited June 15 by Ruggers Customs

[san-d-2000]

On 6/14/2024 at 11:44 PM, mytek said:

It's not the composite mod, so that only leaves the last two possibilities.

That is good to know, would hate to remove the composite mod.

 

22 hours ago, Ruggers Customs said:

One thing I do differently now is I won't accept any F18a install jobs unless the F18a itself comes directly from Arcade Shopper.  I've ran into too many problems with others making F18a boards (now that the older model is open source) and there always seems to be some sort of an issue.  With Arcade Shopper, Greg is getting his boards directly from Matthew Haggarty who created the F18a.  Working directly with Greg and Matthew always makes things easier if there are issues too. 

Great to hear this as i have a F18a on backorder with Arcade Shopper!

 

22 hours ago, Ruggers Customs said:

Plus, 3rd parties generally try to pin the blame on the customer or installer when things go south.  

This is exactly what happened to me, the board started corroding after a couple of days so i send the seller some pictures,  immediately he went into defensive mode and pointing the finger at the installer, during all communication i really had to bite my tongue.

 

@mytek, @Ruggers Customs thank you both for sharing your thoughts.

Edited June 16 by san-d-2000

[Tursi]

I wonder if the builder is using corrosive flux and not washing the board...?? Seems pretty unlikely but yeah, I'm with the others. I have never heard of anything like that.

 

Matt's stuff is 100% top notch. He puts in the time to make sure everything he builds is perfect and stands fully behind them.

 

[matthew180]

I can't tell for sure if that is one of my boards, but I don't think so.  I'm pretty sure I never sold any with all red jumpers, and that PCB house serial number is not one I recognize.  I have never had anyone report corrosion problems like that, and I don't think any reputable PCB assembly house would use acid flux without washing the boards (and even then only use acid flux if specified by the customer).

 

It looks like whoever did the assembly was not aware they were using an acid flux or acid-based solder, or... IDK... why anyone would do that intentionally?

 

The only F18A boards I am making now are MK1 boards, and I'm only selling them through ArcadeShopper.  I know the MK1 is not always available, but I am trying to get caught up with the demand.

 

If you have an F18A that I built, and it fails, I will repair it.  If you actually damaged it somehow (it happens, old computers have power supplies that blow, etc.), I will repair it for a flat fee of $40.  Over the last 12 years I have probably repaired less than one F18A a year, so they are either really reliable or people are just not contacting me when they fail.

 

[san-d-2000]

Hi Matthew,

 

I did not get this board from you but from another seller who I would not recommend to anyone.

 

I have now ordered one of your boards through Arcade Shopper, so it will be replaced soon.

 

Edited June 21 by san-d-2000

[rietveld]

On 6/20/2024 at 10:27 PM, matthew180 said:

I can't tell for sure if that is one of my boards, but I don't think so.  I'm pretty sure I never sold any with all red jumpers, and that PCB house serial number is not one I recognize.  I have never had anyone report corrosion problems like that, and I don't think any reputable PCB assembly house would use acid flux without washing the boards (and even then only use acid flux if specified by the customer).

 

It looks like whoever did the assembly was not aware they were using an acid flux or acid-based solder, or... IDK... why anyone would do that intentionally?

 

The only F18A boards I am making now are MK1 boards, and I'm only selling them through ArcadeShopper.  I know the MK1 is not always available, but I am trying to get caught up with the demand.

 

If you have an F18A that I built, and it fails, I will repair it.  If you actually damaged it somehow (it happens, old computers have power supplies that blow, etc.), I will repair it for a flat fee of $40.  Over the last 12 years I have probably repaired less than one F18A a year, so they are either really reliable or people are just not contacting me when they fail.

 

Hey.  How are you. 

 

 

my f18a looks like the one inn the picture.  Hans made mine

 

BTW i bought one of your mk1s for my Nabu but it wont work in there for some reason. I actually swapped the f18a into the nabu and put your mk1 into my colecovision.. Now both units work. 

 

 

[rietveld]

On 6/21/2024 at 3:40 PM, san-d-2000 said:

Hi Matthew,

 

I did not get this board from you but from another seller who I would not recommend to anyone.

 

I have now ordered one of your boards through Arcade Shopper, so it will be replaced soon.

 

I can verify that Matthews mk1 works great.  I have it in my Colecovision and use it with my expansion 3 Adam

[matthew180]

On 6/25/2024 at 12:17 PM, rietveld said:

BTW i bought one of your mk1s for my Nabu but it wont work in there for some reason. I actually swapped the f18a into the nabu and put your mk1 into my colecovision.. Now both units work. 

 

There are some ongoing unknown problems with the NABU, and it has been very frustrating.  I have a NABU for testing, but I cannot reproduce the reported problem of the failure at power-on (mine always works).  However, I did fix my NABU since the motherboard is poor quality and the bodge-wires all need to be resoldered.  But it is mostly speculation about what the problem is, until I can reliably reproduce the symptom.