660AV, getting no video output through VGA adapter

[einarmr]

Hi all!
From what I understand, I'm not the first person to struggle with a VGA display adapter dongle and a flatscreen display.

I have:

• this dongle from eBay
• a Dell 1907FPf display
• a Macintosh Centris 660AV that I just bought.

The seller of the 660AV has apparently recapped it, and it's supposed to work. It chimes when powered on, and the hard drive tic-tick-ticks just like it's supposed to, so I'm assuming that the Mac itself is good.

The dongle supports six modes: Composite sync (1), another composite sync (2), sync on V (3), sync on H (4), separate sync (5) and sync on green (6).

1. Which sync would work best on this Mac, out of the six different ones supported by the dongle?
2. Do I need to get another dongle, perhaps?
3. ...or would I be better off getting another display?

Needless to say, perhaps, I've already tried a gazillion different modes with the DIP switches on the dongle, and my display just won't light up. I do have an old 17" Apple Multiple Scan Display somewhere (in my parents’ house... somewhere), so I could use that to verify that the video output from the 660AV is good. However, I do believe that the Mac itself is OK.

Any help would be highly appreciated.

-Einar

 

[Forrest]

The 660AV should Support 640 x 480, 800 x 600 and 1024 x 768. Sync on green should not be used. The Apple Multiple Scan Display should work fine with your Mac. On the Dell, you should select the VGA input and not DVi input. Good luck finding the correct settings.

 

[einarmr]

As long as I stay away from sync-on-green, all the other modes that the dongle provides should work? Any recommendation on what to use? Separate sync (5), perhaps?

I am of course aware that I must select VGA input on the Dell, not DVI.

According to the Dell docs, that display only supports VESA modes. Does that matter?

 

[shadedream]

You shouldn't need a dip switch dongle like that for the Centris. There are probably modes that will work, but it'll be a lot easier to just use one of the passive multisync adapters instead. You only really need the dip switch and sync on green ones for systems like the Macintosh II series.

 

[Forrest]

I don’t know the correct switch settings for sync. I was just pointing out sync on green is wrong.
Your adapter should work with the right settings.
The no switch multi sync adapters work great.

 

[einarmr]

Thanks @Forrest and @shadedream ! Any specific recommendations for a multisync adapter without DIP switches, from e.g. Amazon or eBay? Just like in the old days, there are a gazillion adapters to choose from… Getting a specific recommendation would be very helpful.

 

[cheesestraws]

You should be able to set the 10 dip switch dongle you have to do multisync - or at least you can with all of mine.

If it doesn't work with the adapter set to multisync, the hardcoded multisync adapters won't work either.

One other thing to do would be to explicitly set the DIP switches to VGA rather than multisync and try that in case you have some kind of timing issue.

 

[Phipli]

Some of the switch crib sheets here :

DIP switch settings for Mac to VGA adapter

A year or two ago, I remember seeing a big list someone had to put together of all the common brands of Mac to VGA adapter, and a link to the instructions with DIP switch settings for each one. I can't remember where I saw it, though, and Google isn't leading me to it. Anyone remember this list...

68kmla.org

This is the most common one :

Like cheesestraws says, set it to VGA and mode 5, i.e. 2,3,6,7

 

[einarmr]

I wonder if there is some kind of voodoo with this machine after all – it’s not just the video adapter dongle.

After power cycling many times, for trying out various adapter settings, it no longer chimes like it used to do (meaning: now it doesn’t chime at all). Also, the hard drive doesn’t spin up anymore (while the PSU fan does spin). Interestingly (or, weirdly), when disconnecting the SCSI ribbon cable from the drive, it spins up. Makes no sense to me.

Any ideas where I should start troubleshooting? Is the PSU to blame?

 

[einarmr]

OK, something is definitely odd, but after leaving it alone for a while, it booted with VGA adapter set to 2,3,5=on.

Thanks everyone!

 

[Phipli]

View attachment 60471View attachment 60472View attachment 60473View attachment 60474
I wonder if there is some kind of voodoo with this machine after all – it’s not just the video adapter dongle.

After power cycling many times, for trying out various adapter settings, it no longer chimes like it used to do (meaning: now it doesn’t chime at all). Also, the hard drive doesn’t spin up anymore (while the PSU fan does spin). Interestingly (or, weirdly), when disconnecting the SCSI ribbon cable from the drive, it spins up. Makes no sense to me.

Any ideas where I should start troubleshooting? Is the PSU to blame?

Yeah, start by checking the voltages out of the PSU.

There is a power connector... Front left of the board? Under the CD drive.

But you can check the 5 and 12v from a molex.

 

[Forrest]

If the 5v and 12v voltages are ok while the machine is running, you should check the fan. Is the power supply fan is not spinning, you should replace the fan.

 

[Forrest]

Many SCSI hard drives simply stop working. You should consider a ZuluSCSI or a BlueSCSI replacement.

 

[dougg3]

I can’t explain the no chime situation — that very well may be a power issue -- but I also have a 660av and experienced “no video” issues while testing it.

Apple says this is one of the few models that can experience loss of video when the PRAM battery isn’t installed. I had much better luck with video after I installed a battery. I too was able to get video working by fiddling with power when the battery wasn’t installed, but the battery made it much more robust.

 

[einarmr]

I have a ZuluSCSI being delivered next week

 

[Phipli]

@einarmr has a very good point - do you have a good battery in it? The 610 and 6100 both need The 6100 needs a working battery for video to work properly, it might be the same for the 660.

Edit because duh, I'm using a 610 without a battery. Don't repeat things you heard over the evidence in front of your eyes phipli

 

[einarmr]

No battery installed here

 

[Phipli]

No battery installed here

Try adding a new one, it might be some of your problem. Check Amazon for "14250", 3.6v batteries. Often SAFT brand.

 

[Phipli]

No battery installed here

Just edited my post above fyi. The 610 does work without a battery.

 

[dougg3]

It‘s been a while, but I think without a battery, I was often able to get my 660av to show video by rapidly power cycling it a few times after it was first plugged in. It was super weird and erratic. I’m confident the 660av is one that needs a battery for reliable video. Apple says so at the link above, and I saw it with my own eyes too.