I need some help with a studio display ADC monitor and USB

[Patnukem]

This is a bit of a story but I will try and make it short. I have a 17" lcd ADC monitor. The usb/brightness keeps going out and it is a common problem, the general consensus is a bad usb hub on the main board, and a used main board with working usb ports, when I put it in Saturday it worked the first time then my girlfriend used it Sunday and it stopped working, so im sure it is the problem. So seeing as I do not want to try and get yet another one and see it fail (I am told by other forums that sometimes they will come back to life for a bit if left unplugged for a while). So I was considering installing, since it would fit, a usb hub in to the monitor and connect it to the proper pins of the adc cable. the speakers would not work in them anymore since It would not have the special 10v mode but I could care less note this picture I made of the pinouts for the two ports on the back of the monitor,

. I have found the pinouts for the adc here http://pinouts.ru/Video/apple_adc_pinout.shtml and see 3 of the usb pins but I would like to know how they are wired up in the adc to dvi adapter, so if someone has one of the off brand ones that are easily opened I would like to see how it splits off the usb for the usb port. Honestly from the pinout I do not know if this will work so that is also part of this long question. Thank you for reading this short novel!

I just added a picture with the main board and the brightness usb interface pinouts as listed on the board.

After unplugging the cables on the main board and plugging them back in the usb/brightness works again but I think it will go out again soon so I still want to rig in a usb hub to make this error never happen again.

I also used a multimeter to see what pins the eight wires from the main board go to on the adc and found the following

1. brown ground

2. yellow adc pin 19 DDC CLOCK

3. blue adc pin 9 DDC Data

4. orange adc pin 3 LED

5. red adc pin 13 soft power

6. white adc pin 22 Usb Data+

7. green adc pin 21 Usb Data-

8. black ground

so I guess I kind of answered my own question here, if I left all the wires plugged in but 6,7 and ran them to the hub with a ground wire and the 5+vdc from the labeled brightness port it should work, I would have to wire in the two ports on the back directly to the hub as well as the brightness, but I do not know what brightness wires are the usb data just the ground and +5v

 

[Patnukem]

I guess what I am asking is there an easy way to tell where data+ and data- are? out of 1.mon on 2.gnd 3.lanuch 4.NC 5.gnd 6.+5V 7.fn lanuch I think they ment launch since this is for the launch switch. and I know 6,5,4,2 are not data +/- so its ether turned to usb somewhere else or its most likely fn lanuch and lanuch. sinch 5v goes to the switch could the usb signal be generated on the board and changed to fn lanuch ect.

 

[Patnukem]

I know I most likely to be talking to my self but hey someone else may eventualy want help with this.... but I doubt it. anyway the little square ic in that says

phillips

1122a bd

ca2705

ts143d

so I found a philips isp1122a that is a usb stand-alone hub ic. so I found it has some downstream port data- (DM#) and data +(DP#) so I do know there is some resistance on the ic to the brightness board. I may be getting too over my head but now I have a spare board to do tests on so that may help.

 

[trag]

If you visit Phillip's website and hunt a lot you may be able to find a datasheet for that chip, which will identify what all the pins do for you.

 

[Patnukem]

I did get one for the isp1122a (that is actually how I found it) and it has the same shape and the same number of pins and it does seem to connect to the two usb ports with DM1 DP1 DM2 DP2 with DP0 DM0 being upstream so I should guess that DM3, DP3 are connected to the brightness, but what I am not sure of is can you plug downstream port 1 D− connection (analog) staight to a hubs data - port and ect. with the rest of the connections. The ports on the back all seem to have about 22ohms of resistants to the chip so I do not know if that is important.

 

[Patnukem]

interesting. I found that the huge ic on the board is a MC68HC908BD48 Microcontroller Unit that has usb data outputs, it connects directly to DM3 and DP3 so it would seem I am on the right track, this also means that even though the brightness control board and the power board are the same part numbers, it would appear that (since I know the power button on the monitor does not use usb) it does not turn into a usb device until it reached the MC68HC908BD48 chip. Now I am almost certain I could wire up a hub to the data +/- of the brightness/usb ports but I am not sure if I could use the same 5v or if I would have to find a new way to get power in there. I would have to leave some things connected I could always make a adc/usb adapter to test it on another computer before I install it and kill the display

 

[Patnukem]

After looking over the usb connection on the ADC connector I am stuck trying to figure out where the 5vdc comes from there are TMDS Data5+/- pins but I do not think they are for the usb hub I am left with

2. yellow adc pin 19 DDC CLOCK

3. blue adc pin 9 DDC Data

4. orange adc pin 3 LED

5. red adc pin 13 soft power

so it mus be the soft power, I do not know what voltage this puts out but If it is hight then 5vdc I am sure the board converts it to 5 for the hub. I think when installing a hub I will just leave the usb data+ and data- unhooked to the board and I hope that is enough to bypass the on board hup (I might also sever the usb hub chips 5vdc connection as well)

Also does anyone know what pin 23-USB Return on the ADC connector is for it does not seemed to be hooked up to the board.