A4000 sound problems and AmigaKit

[Castellen]

Fuzzy sound errors are a clear indication of Paula problems. Replacement is not trivial and Amigakit don't do it.

Thanks for the nice comments :-)

In nearly all cases, audio distortion problems are the result of leaking capacitors, which corrode components and damage PCB tracks and vias.  I've repaired hundreds of Amigas with such problems, and it's incredibly rare for Paula to develop issues or need replacement.

Can't speak first hand of AmigaKit's repair service, but as I understand it, the fixed price is for capacitor replacement only.  Repairs are extra, and I'm not sure if return freight is included in the price, I wouldn't expect so.

All my jobs are priced individually based on the work required, though a typical price for audio stage repair, replacement of all 22µF and 4.7µF capacitors, repairs to RTC circuit as required (not including replacement battery price), all parts, labour, full testing and return freight, it's around NZ$150.  Use a currency converter to get your local currency.

Boards are returned with a written test sheet, complimentary battery replacement stickers and I don't charge PayPal fees.  All common parts are in stock and turnaround time is typically 5-7 days.  90 day warranty on all labour and new parts.  Freight to NZ isn't too bad for a 1.2kg board, it's about NZ$40 each way.

Am in the process of generating automated price lists for all this kind of stuff, been getting my head around making ARexx do web stuff.


By all means shop around for price and convenience.  Makes sense if you can save a bit of time and money by using a service close to you.

Contact me for any more detail.  And if you're capable of working with electronics, but not sure where to start on such a job, I've written this guide which explains it all.

[Castellen]

You replace only these ? Not ALL the CMS caps on the board

Yes, the liquid electrolyte in the 47µF and 100µF capacitors is quite stable by comparison.  Tests from random samples show that the marked capacity is within tolerance and leaking in these capacitors is much less of a problem.

Obviously if the customer wants to pay extra to have them replaced, then that's fine.  Generally I don't replace them unless they are suspect or there are other reasons to do so.  Keeping in mind this is a commercial service, you've got to draw the line somewhere, else repair costs quickly begin esculating to the point where it's no longer economic.

Realistically, you could replace every part on the board that has a possibility of maybe failing sometime, such as SIMM sockets which are known for retaining clips breaking, or every IC socket in an A3000 because they're common trouble causes too.  But the majority of customers simply want to spend the least amount possible to have things work reliably.  A minority of customers do pay to have all these such parts replaced to future proof themselves as much as possible, so no problem.

This is from over 15 years commercial experience at this, and not just with Amigas...

[Castellen]

Give me a price for full caps replace (not simm socket, not battery - have removed). My location is Greece Athens Galatsi 11147.

That will be around NZ$170 (85 Euro) for parts, labour, testing, return freight.  Will be less if there's not too much corrosion damage around the real time clock area or analogue audio stage.

I've had a huge amount of repair work from Greece and Italy in the last few months, what are you guys doing to your Amigas all of a sudden?!

[Castellen]

@bakoulis:
Sure, please send me a private Email, I don't openly post address details on the internet.

@Cosmos:
No problem if you can convince all of my customers to pay the extra for this.  It's not the kind of cost I can afford to absorb, do you realise my hourly rate is 10 Euro?  Even I think that's stupidly low, it's not like I'm making a lot out of this to begin with.  Unfortunately $30000 of test equipment doesn't pay for itself by magic.

@gertsy:
Do you have access to a spare riser card to narrow down the problem?  Sounds like a possible termination problem on the riser card.  There are resistor networks along the top edge of the card which provide bus termination, one of these may be damaged.  You can measure them using an Ohm meter, keeping in mind they're a network with a resistor to +5V and another resistor on the same line to GND, can't remember the exact vaules, but you'll soon work it out.  All the data and address bus lines should measure the same.  Can scan the schematic for the riser board for you if you want to look further yourself.  Doubt if it's a damaged internal track, I think it's only a 2-layer board to start with.  And a damaged track would usually result in more serious problems such as certain slots not working at all.

Could be a dodgy Zorro card causing issues as well, have you tried other combinations of cards, and combinations with one card removed?

Failing that, I'm happy to have a look for you, just send me an Email.

[Castellen]

http://cosmosamiga.blogspot.com/2010/03/preparer-un-colis-ii.html

There's some really good pictures there, been meaning to take some for my packing guide as well, but I never seem to get the time.

I'd strongly recommend using ESD safe packaging.  Bubble wrap and EPS foam chips are certainly not what I'd directly pack static sensitive items in.  Should be placed into an anti-static bag or covered in a layer of aluminiumn foil first to minimise the chance of damage.


As for the additional capacitor replacement time, I'm guessing there are around 12 pieces.  Haven't timed myself, but I'd estimate closer to 30 minutes for the job to be done correctly.  Some of the capacitors are in tricky spots with plastic components nearby which you need to avoid damaging with hot air.  Plus there's the additional $12 in parts, it all adds up.  As I said, if customers request it, I'm more than happy to do it.  However, although the capacitors are aging like every other component on the board, I don't recall the last time I saw an an A4000, A1200, A600 or CD32 with the 100µF, 47µF or 10µf parts failing, so there is less urgency to replace them.  The 4.7µF and 22µF parts are a different story; the electrolyte is far less stable, so it's necessary for all of these parts to be replaced.