A4000D Motherboard cold solder reflow successful!

[tonyvdb]

So Ive been taking to a friend about my Amiga 4000 intermittent issues. He suggested putting the entire motherboard into the oven at 350F for no more than 10 min to basically reflow the solder.
Seems like sound advice given at this point I have very little to loose.

any thoughts to this?

UPDATE:
I decided to try it and it was fully successful! everything is functioning and no more issues with video dropouts and intermittent ram loss.

[Plaz]

While such a technique has worked for some kinds of equipment, that doesn't necessarily mean it's a good thing for your 4000. Temps hot enough to reflow solder will also potentially melt any of the plastics installed too. What trouble are you having and what steps have you taken so far to try and zero in on the problem?

A method I've used successfully to locate problems is to put light pressure on components or areas one at a time while either watching a good system bootup, or applying with the system running and watching for lockups.

Another is to use a heat gun very selectively.

Depending on the issue you're having, it could also be you have a chip somewhere that's overheating and failing intermittently, or a cracked chip socket.

Plaz

[danbeaver]

Using a heat gun while shielding the plastics with aluminum foil is by far safer.

[tonyvdb]

well the list is rather long,
Intermittent video, I have the Indovision AGA (sometimes video just drops out or does not even show) Ive reset the indovision a couple times.
Ram cuts in and out (already removed and cleaned with eraser and rubbing alc)
I have striped down to the bare motherboard and it still happens if i put pressure on the board in random spots.
The frustration is simply that when I start putting things back in it becomes even more flaky.
I also have issues with my Wico joysticks not working right (not centered and work strange)
Ive posted questions on these issues here and it just seems to be the age of the motherboard in general.

[Damion]

I wouldn't do it, considering the age (fragility) and value of the board, better to send it to someone like like Anthony Hoffman in NZ.

Not to say it isn't possible, but I have yet to see one of those boards flaky or dead due only to a poor solder joint. I have however seen them with lots of other problems, that a home "bakejob" won't fix (SMD capacitors being the obvious one). Motherboard RAM cutting in and out, if not a contact issue with the SIMM is generally some sort of damage from battery leakage.

[QuikSanz]

Not a really a good idea to do that. Pull the board and inspect for non shiny solder joints. If you see some, re-solder by hand. If you see none send for recap and cleaning. It's not expensive.

[danbeaver]

But for full diagnostics and repair, consider Amigakit or (come September) Anthony Hoffman in NZ.

[Gazbonk]

As well as the capacitors might also be the power supply, don't mess with it send it away to a specialist so it can be given a full service, it will be worth it.
Don't forget the A4000 was released in 1992 (23 years old)

[tonyvdb]

Well, I decided to try it because I love to live dangerously LOL
Let it cool and put everything back together and low and behold, everything is working 100%!

I still have to test the joysticks but all ram is reporting, no more video dropouts and nothing is visibly wrong.

On a side note I towerised the A4000d a long time ago and replaced the power supply with a good quality 400watt ATX PS and modded the connector so it would fit the motherboard. The battery was replaced a few years back and there was no damage from the previous one.

A Happy Camper

[danbeaver]

May the Lord bless you and keep your Amigas safe!

[trekiej]

Amen.

[gertsy]

Wow. How did the plastic RAM sockets go?

[tonyvdb]

The ram sockets did fine (I removed the ram when I did this as well as the 3640). The only part that seems to have been slightly warped and I mean slightly was the Buster 11 chip socket however as I said everything is working perfectly

[ChuckT]

So Ive been taking to a friend about my Amiga 4000 intermittent issues. He suggested putting the entire motherboard into the oven at 350F for no more than 10 min to basically reflow the solder.
Seems like sound advice given at this point I have very little to loose.

any thoughts to this?

UPDATE:
I decided to try it and it was fully successful! everything is functioning and no more issues with video dropouts and intermittent ram loss.

What I would tell you is to check the solder joints.
I wouldn't put a mother board into any oven.
An oven for solder reflow is different than your home oven.
You risk drying up the capacitors.
There is special solder equipment for solder reflow and it usually is done with a soldering station (hot air station) that has a heat gun so you don't add the heat to parts that don't need it.

https://learn.adafruit.com/adafruit-guide-excellent-soldering/making-a-good-solder-joint

See page #25:

https://learn.adafruit.com/downloads/pdf/adafruit-guide-excellent-soldering.pdf

To reflow, you are probably better off with a hot air rework station:

http://www.circuitspecialists.com/hot-air-station

And don't forget to use flux.

[danbeaver]

Chuck, its a wee bit late for your advise, and while putting a motherboard in a kitchen oven is, "Bold talk for a one-eyed fat man" (True Grit 1969), it is done and seems to have worked to the satisfaction of the owner.  He appears to have considered the outcomes and made his decision.

Bravo!  But, "Son, you're on your own..." (Blazing Saddles 1974)