22in Cinema Display ADC usb not working

[bjar]

I just got this display for $10 off craigslist. It is plugged in via ADC to my powermac g4 fw800. Video card is an mx4. The USB ports on the back of the display are not working. I have never dealt with ADC displays, so wondering what kind of troubleshooting steps I should take to identify the issue. When a Mouse is plugged in it appears to get power because it lights up, but the pointer does not move. Keyboard does not work either, both ports appear to be affected. Both the keyboard and mouse work when plugged into the USB ports on the back of the g4. I have an ADC to DVI adapter on the way from ebay, so I will try that as well when it arrives. Thanks!

 

[eyoungren]

Disconnect the cable and then take a VERY good look at the pins. You probably bent a pin or two inserting the connector.

If you see a bent pin, push it back straight with a small screwdriver.

Best practice when inserting the ADC connector is to grip the sides and push in the tabs then push the connector in as straight on as you can. Once it's in let go of the tabs so it locks. That avoids any bent pins.

 

[bjar]

Disconnect the cable and then take a VERY good look at the pins. You probably bent a pin or two inserting the connector.

If you see a bent pin, push it back straight with a small screwdriver.

Best practice when inserting the ADC connector is to grip the sides and push in the tabs then push the connector in as straight on as you can. Once it's in let go of the tabs so it locks. That avoids any bent pins.

No pins appear to be bent. Just tried and the brightness control buttons on the display work, which I assume is communicated through USB. Didn’t think of doing that earlier. So I’m thinking I can rule out the g4 and the connector.

 

[philgxxd]

Do you get a response on-screen when you change the brightness?
I mean the typical screen overlay which fades out slowly in OSX.
If so the usb communication is working so I would think the port itself having a problem.
Mine's are also really temperamental and I had a lot of times they stopped working. Even dismantled a few times the screen to get to the ports and mainboard to reseat the cable.
I'm using a G4 MDD and used it with and without the ADC converter brick.

 

[1042686]

Wow $10 bucks. What a score even with wonky usb If you think it’s the port assembly, below is a ifixit guide.

https://www.ifixit.com/Guide/Apple+Cinema+Display+M8149+USB+Port+Replacement/5402

Dependent on the build revision of the display, this assembly on eBay may work for you - (Not my auctions).

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/223279410722

Heck maybe the wire assembly popped off, so may be worth doing a partial disassembly & having look. For the cost of that assembly, You could buy a usb2 pci card & a nice hub & run it off the back of your PMG4?

Cost wise this would be a much more cost-effective fix, expanding usb2 I/O to 4e/1i ports vs repairing the usb functionality on the adc 23” CD.

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/131931957505

Still,I’m also kind of OCD (when I can afford to be!) in regards to my kit & prefer everything working as it was intended.

 

[bjar]

Do you get a response on-screen when you change the brightness?
I mean the typical screen overlay which fades out slowly in OSX.
If so the usb communication is working so I would think the port itself having a problem.
Mine's are also really temperamental and I had a lot of times they stopped working. Even dismantled a few times the screen to get to the ports and mainboard to reseat the cable.
I'm using a G4 MDD and used it with and without the ADC converter brick.

Yes the display responds to the brightness controls. I guess I’ll take it apart and reseat the cables.
[doublepost=1548423038][/doublepost]

Wow $10 bucks. What a score even with wonky usb If you think it’s the port assembly, below is a ifixit guide.

https://www.ifixit.com/Guide/Apple+Cinema+Display+M8149+USB+Port+Replacement/5402

Dependent on the build revision of the display, this assembly on eBay may work for you - (Not my auctions).

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/223279410722

Heck maybe the wire assembly popped off, so may be worth doing a partial disassembly & having a look. Then again what if it isn’t the usb port and is something more difficult like a faulty assembly connector. For the cost of that assembly, You could buy a usb2 pci card & a nice hub & run it off the back of your PMG4?

I installed a number of these cards in a couple different PMG4s. Cost wise this would be a much more cost-effective fix, expanding usb2 I/O to 4e/1i ports vs repairing the usb functionality on the adc 23” CD.

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/131931957505

Still,I’m also kind of OCD (when I can afford to be!) in regards to my kit & prefer everything working as it was intended, so I get that urge too.

Anyhoo, best of luck to you.Let us know how you make out.

I think I’ll try reseating the cables. The machine has Bluetooth and I have the Bluetooth white keyboard and Mighty Mouse so that should look great with the display, however, like you said I like things to work how they were intended. But for $10 I guess I can’t complain! Thanks for all the help.

 

[1042686]

Yes the display responds to the brightness controls. I guess I’ll take it apart and reseat the cables.
[doublepost=1548423038][/doublepost]
I think I’ll try reseating the cables. The machine has Bluetooth and I have the Bluetooth white keyboard and Mighty Mouse so that should look great with the display, however, like you said I like things to work how they were intended. But for $10 I guess I can’t complain! Thanks for all the help.

NP. The USB ports stopped on one of mine shortly after getting it & reconnecting the cable (popped off) worked.

 

[bjar]

NP. The USB ports stopped on one of mine shortly after getting it & reconnecting the cable (popped off) worked.

The thing was in my trunk for 3 days traveling across Texas before I got it home so may have shaken something loose. Going to take it apart this weekend and see if I can figure out what is going on. I don’t want to bug the seller to ask if the usb worked before I acquired since he sold it to me so cheap.

 

[bjar]

The thing was in my trunk for 3 days traveling across Texas before I got it home so may have shaken something loose. Going to take it apart this weekend and see if I can figure out what is going on. I don’t want to bug the seller to ask if the usb worked before I acquired since he sold it to me so cheap.

Well reseating the cables didn’t work. But at least I got to give the display a good cleaning while it was apart. I’ll order the USB ports some day and see if that works. If the board is messed up or something then I will just give up and be thankful that at least the only thing not working is the usb.

I also tried through the adc to dvi adapter and they don’t work that way either.

Need a desk to put this stuff on.

 

[eyoungren]

Well reseating the cables didn’t work. But at least I got to give the display a good cleaning while it was apart. I’ll order the USB ports some day and see if that works. If the board is messed up or something then I will just give up and be thankful that at least the only thing not working is the usb.

I also tried through the adc to dvi adapter and they don’t work that way either.

Need a desk to put this stuff on.

Not to rub salt in the wound, but look at it this way. These USB ports are USB 1.0. So other than keyboards or mice, or small devices that don't really need USB 2.0 they provide no real benefit.

I have three displays (all hooked up to a powered USB 1.0 hub) and I never use the ports on the back. Technically, that's because getting to the ports on the back is difficult, but my USB 2.0 hub is far more useful to me.

 

[bjar]

Not to rub salt in the wound, but look at it this way. These USB ports are USB 1.0. So other than keyboards or mice, or small devices that don't really need USB 2.0 they provide no real benefit.

I have three displays (all hooked up to a powered USB 1.0 hub) and I never use the ports on the back. Technically, that's because getting to the ports on the back is difficult, but my USB 2.0 hub is far more useful to me.

Yeah I know, I just like things to work, and fixing it gives me something to do.

 

[Bug-Creator]

Just tried and the brightness control buttons on the display work, which I assume is communicated through USB.

Without looking up schematics I'd still bet those are ADB (just like the PWR-button).

 

[bjar]

Without looking up schematics I'd still bet those are ADB (just like the PWR-button).

That probably explains why I get the on screen brightness indicator when connected through ADC but not when connected to the ADC to DVI converter. Power button also does not do anything when plugged into converter. I am assuming that is normal.