Quadra 700with no Video Output ...

[franklyn]

I have a Q700 with the fault there is no Video Signal Output.

There is no sad mac sound so I think the mainboard is fine except the Video Out. The NVRAM battery wasn't leaking but the video chip has an oxidized spot on three legs and one spot was soldered.

Need some tips what should I do with the oxidized legs ...?


Would be helpful to have the Quadra 700 schematics ...

 

[Bolle]

Would be helpful to have the Quadra 700 schematics ...

Like so?

Macintosh Quadra 700 & 660AV Schematics : Apple Computer Inc. : Free Download, Borrow, and Streaming : Internet Archive

OEM Schematics for the Apple Macintosh Quadra 700 and 660AV Computers.

archive.org

 

[franklyn]

Cool ...


Thanks

 

[franklyn]

unsatisfactory result

It's working again, apart from cleaning a few via´s with isoproanol, I didn't do anything else.

Power supply is fine

 

[franklyn]

The video failed after a while again and this time I resoldered the two missing spots on the video chip and so far it seems to be working.

The problem is that the oxidized areas cannot accept new solder even with a lot of flux !!!

 

[davewongillies]

Need some tips what should I do with the oxidized legs ...?

The usual way I do it is to soak/clean the oxidized areas with white vinegar (give it a scrub with a tooth brush then leave the vinegar for 5-10 minutes) then clean up the vinegared area with IPA afterwards. Then once its all dry hit it with the flux (I've used chip quik recently and found it was great for this kind of situation) then resolder the legs. One tip I got recently was when you get up to the fluxing step was to keep rubbing the flux on the oxidized area with your soldering iron until it feels "smooth". The oxidized areas can tend to feel a bit "rough" or "crusty".

With particularly tough oxidization I might carefully try and scrape some of it away (I used a pair of fine tipped tweezers I had but I've also seen people use things like dentists scraping tools)

 

[franklyn]

... a little difficult because there are only three legs affected from the video chip. But it's been running for a whole day now ...

 

[davewongillies]

... a little difficult because there are only three legs affected from the video chip

What I described above can be done to any surrounding legs and it'll be fine.