Radius Precision Color 8-24X behavior on IICi

[mapomme]

Hello,

I have a IIci (20Mb RAM, BlueSCSI, fresh reccap + new power supply) with Mac OS 7.5.5 working fine.

Just bought a Radius Precision Color 8-24X (unknown condition) and I'm not having expected results. I tried it in different slots with the same issue. The IIci starts, sound is ok, usual RAM check time, then on my LCD I get pink and green colored lines and nothing happens next. No HDD activity.... nothing.
Please note, that I'm using a 10 dip switch adapter with good results on the integrated graphics.

Any idea ? thanks in advance.

 

[Phipli]

First thing I'd do is check the connector for bent pins, and the board for damage.

 

[mapomme]

Thanks for the advice, all pins are ok. I made a detailed visual inspection, can't find/see anything wrong.
One easy thing might be the replacement of the 30yo tantalum capacitor.

 

[Phipli]

One easy thing might be the replacement of the 30yo tantalum capacitor.

Tantalums are fine unless they fail. That won't be causing issues unless it has failed, which is usually visible (it would have a burn dot or worse).

A high resolution, well lit, clear photo of both sides of the card might help.

 

[mapomme]

thanks, for you replies, I appreciate.
please see high resolution pics as suggested, it's the best I can do for now.

 

[Phipli]

thanks, for you replies, I appreciate.
please see high resolution pics as suggested, it's the best I can do for now.

It looks pretty tidy. Do you have a couple of closeups of C502?

Other than that, nex thing I would do would be carefully remove the ROM, the. Give it a bath in 99.9% IPA. Then put it somewhere warm to dry for a few hours (or a day) and test it again.

 

[mapomme]

C502 looks good. Also, I tested it "in situ" and for what it worth with my multi-meter : no shortcut.
I gave a bath to the EPROM, and tried again : same issue. Except that once I got a crash sound of the mac.

Can I try without the EPROM ?

 

[Phipli]

C502 looks good. Also, I tested it "in situ" and for what it worth with my multi-meter : no shortcut.
I gave a bath to the EPROM, and tried again : same issue. Except that once I got a crash sound of the mac.

Can I try without the EPROM ?

I think I see corrosion:



This, in addition to the state of the crystal, makes me think this has been stored badly. You're going to need to get an angle poise lamp and a jeweler's loop and look for corroded traces and corroded chip pin/pad interfaces.

Or use your phone to zone in, but you'll need better photos than the ones you've been sharing. The one above is the first I've been able to see the weird shade of green that suggests corrosion. I had seen the state of the crystals casing though so I was wondering.

 

[mapomme]

I turned around U501 and took pictures as you suggested, for reference I also took a picture (IMG_0007) at the opposite of the crystal location.
I'll conduct few continuity checks later on and I'll probably give an IPA bath to the whole thing.
I agree the crystal casing looks bad. I'll try to find a replacement as well as the tantalum capacitor.

 

[Phipli]

It doesn't look really bad, but I think it has been stored somewhere humid. Worth searching the board for dodgy looking areas.

 

[joshc]

I turned around U501 and took pictures as you suggested, for reference I also took a picture (IMG_0007) at the opposite of the crystal location.
I'll conduct few continuity checks later on and I'll probably give an IPA bath to the whole thing.
I agree the crystal casing looks bad. I'll try to find a replacement as well as the tantalum capacitor.

What did you take these photos with? Really nice high res shots.

 

[mapomme]

Hello, sorry for the late reply, I'm using that kind of thing. Very convenient.
Sensor Sony IMX307, 100x

 

[cheesestraws]

That's a nifty thing!

 

[mapomme]

Well... I made some progress, I changed the crystal, and now each time the mac boots correctly and loads Mac OS 7.6.1 in black and white mode.
Unfortunately, it usually freezes few seconds after the "desktop" is fully loaded.
Several times, I was able to go to monitors control panel, and try to change from B&W to color and it freezes instantly.
Same when I connect 2 monitors, each time I try to modify the radius settings, it freezes the mac.
I zappped the PRAM several times too.
I'm not using any RADIUS driver.

FYI, the crystal I found is a 4.31818MHZ, the original one is labelled C14.3181 ==> frequency issue ?
any ideas ?

 

[Phipli]

Well... I made some progress, I changed the crystal, and now each time the mac boots correctly and loads Mac OS 7.6.1 in black and white mode.
Unfortunately, it usually freezes few seconds after the "desktop" is fully loaded.
Several times, I was able to go to monitors control panel, and try to change from B&W to color and it freezes instantly.
Same when I connect 2 monitors, each time I try to modify the radius settings, it freezes the mac.
I zappped the PRAM several times too.
I'm not using any RADIUS driver.

FYI, the crystal I found is a 4.31818MHZ, the original one is labelled C14.3181 ==> frequency issue ?
any ideas ?

Crystals can be tricky - different ones have different requirements for the surrounding components... I'm not the best at that sort of thing.

But that does sound like very good progress!

 

[tigerstorm]

I'd do continuity and resistance tests on the suspect traces. If they aren't great, you could bypass them. But, they really don't look bad enough to me to be broken, unless some damage is hidden.

I would just give the thing a really good cleaning -- some little fleck of metal or broken wire from another component (when it was stored) could be causing an intermittent short. Check under the IC's-- I've had bad dust stuck under there causing problems before. High pressure air and IPA can help dislodge any hidden problem dust.

But, chances are that won't fix it-- but it's relatively easy to try, and it could work.

I'm not an expert on mac IIs, but if this were an old PC, the symptoms you describe would make me suspect the VRAM before anything else. You could try checking all of the ram chips if you have the means (swap them with another card? Have a testing tool?). A brute-force way would be to simply replace them and hope it works.

 

[mapomme]

Thank you tigerstorm to encourage me. Sinve the last post, I may have an other idea.
I have an other mubus graphic card, when I plug it on the slot C sometime the mac does not start. Now I suspect the nubus bus. When I recapped the logic board, I notice some corrosion on the UH1, and it seems to be a common problem. Then I'll change it first, and continu to debug the Radius card.

 

[Phipli]

Thank you tigerstorm to encourage me. Sinve the last post, I may have an other idea.
I have an other mubus graphic card, when I plug it on the slot C sometime the mac does not start. Now I suspect the nubus bus. When I recapped the logic board, I notice some corrosion on the UH1, and it seems to be a common problem. Then I'll change it first, and continu to debug the Radius card.

Good thought. More often, rather than UH1 itself it is corroded traces around the cap C16. There are some important Nubus related traces in that area.

90% of the time chips aren't bed, but just traces and pads need cleaning, repairing and resoldering. Take a well lit, high resolution photo of the area so you can zoom right in to check for trace damage. Then if the solder on UH1 look bad, use extra flux and a little fresh flux to refresh the connections on UH1. If they're really bad it can be easier to remove the chip, clean up the pads, clean the pins and resolder it. Putting a blob of flux on something and then cooking it for a few seconds with the iron can help work the corrosion out, but take care not to put  too much heat into the chip or pads. That said, it's just a basic logic chip and will likely handle more heat than you expect... And will be easy to replace if needed.

 

[danny.gonzalez.0861@gmai]

Good thought. More often, rather than UH1 itself it is corroded traces around the cap C16. There are some important Nubus related traces in that area.

90% of the time chips aren't bed, but just traces and pads need cleaning, repairing and resoldering. Take a well lit, high resolution photo of the area so you can zoom right in to check for trace damage. Then if the solder on UH1 look bad, use extra flux and a little fresh flux to refresh the connections on UH1. If they're really bad it can be easier to remove the chip, clean up the pads, clean the pins and resolder it. Putting a blob of flux on something and then cooking it for a few seconds with the iron can help work the corrosion out, but take care not to put  too much heat into the chip or pads. That said, it's just a basic logic chip and will likely handle more heat than you expect... And will be easy to replace if needed.

I also concur with what Phipli suggests, here is my post from a few weeks ago:

IIci w/ Supermac Spectrum 24 PDQ - No Video Output

Hi everyone, I am fairly new to the 68k Mac world and I managed to grab a Supermac Spectrum PDQ 24 for my IIci and 13" High Resolution Display. The display works fine with the onboard graphics but nothing from the Supermac. I am having issues sourcing the SuperVideo v2.7.5 that is supposed to...

68kmla.org

I had a Nubus card that would warm up but my IIci would not see it which lead me to believe that the card was getting power but something was not letting the IIci access the card. After a bit of tracing I indeed found the trace directly under C16 to be broken although it looked perfectly fine.

A quick bodge wire fixed my issue completely and I've never had another issue. You might need to spend some time with a good drink and a multimeter to see what might be causing your issue.

Good luck!

 

[mapomme]

Thank you all, I'll keep you posted.