Quadra Quandary Quibbles

[macoslove]

So I have this Quadra 605 and I have recapped this bad boy only to have garbled video. Green garble to be more specific. Previously it was not doing anything at all so its something. The previous caps were nasty and I did a good inspection after removing them and cleaning (not ultrasonic) and found no nasty traces, eaten legs or signs of damage.

I have looked across this under magnification and checked legs and solder joints and cannot seem to find anything. And aside from a burnt offering unto some unknown tech-deity I am stuck.

Two images likely wont do any good but perhaps there is something obvious my eyes aren't seeing.

What to do... What to do...

 

[macoslove]

Here is the video output I get. It starts with a bit of green and eventually resolves to grey as shown.

I am at a loss as to where to look from here.

 

[phunguss]

Just curious what you cleaned it with after the recap. Seems like there is some kind of impurity residue still on there (unless its just the photo). Everything seems to have a smoky glaze. Submerge it in IPA and scrub gently with a soft brush (or toothbrush).

 

[macoslove]

That is the residue left after performing the task you describe. An Ultrasonic cleaner is in my future.

 

[GiGaBiTe]

You have corroded traces going to the VIAs in the unpopulated ROM slot between the VRAM slots and the soldered RAM.

There also look to be solder bridges on U26 and U27 on the bottom of the board.

Also, don't use IPA to clean boards, it's garbage and doesn't work. Use CRC Lectra Clean or QD Contact cleaner, which will properly clean flux and remove leaked capacitor residue.

 

[macoslove]

Good to know about IPA. I think this was in a smokers home as well so that would also explain some of the 'film' coating.

 

[macoslove]

Its amazing how proper tools make the difference (or at least better tools) for look at what I see!

I don't see issues with the U26 and U27 but my eyes are not the eyes of a master.

However there are a lot of of discoveries on the via areas. My plain eyes totally missed the repair and the damage next to it...

This ought to be fun!

Thanks so much for the assist and I am excited for the undertaking.

 

[GiGaBiTe]

The PCB under U26/27 looks really sus, like the surface of the board has been scraped away and exposed the layer underneath.

Seems like someone had the board before you and had a botched repair go at it.

 

[macoslove]

Interestingly this machine came from an elderly mans basement as was untouched for quite some time and had a school district listed on it. He reported having procured it at a district auction in the late 90's.

I wonder if he tinkered back then or if it was done at the school. Its case holds the record for the darkest case beige in my spectrum. As thought it was in front of a window for a solid decade.

Additionally I assumed schools were using the LC variants. I never saw any of these in class and I was that generation. And the smoker residue... Perhaps art teacher or shop class...


I plan to remove them and see what it looks like underneath the chips but it may be my horrid lighting and that smeared residue I will properly clean when the recommended cleaner arrives.