I have a cheap portable TV screen “Karowa 7” TFT LCD COLOR TV“ for which I would like to find some new use. The problem is it has an AVIN connector which seems to use USB as its physical connector.
https://s13.postimg.org/4tzxayi4n/image.jpg
I guess the TV has originally shipped with an adapter cable connecting the “USB” pins directly to (most likely) RCA audio and video plugs. Something like in https://forum.allaboutcircuits.com/threads/a-v-out-help-newbie-with-meter.63579/ but with different connector.
There are some USB to RCA cables available in eg. ebay but considering overall quality of the product (not very high) I wouldn’t be very surprised if it was some kind of custom design.
Top side of the PCB, the connector on right: https://s10.postimg.org/wjfxb0epl/image.png
Bottom side of the PCB, the connector on left: https://s9.postimg.org/s5eb1og33/image.jpg
The resistors R608-609 are marked 101, R601 is 472 and R602 is 102. I couldn't reliably measure the capacitors but they may be 600nF. Upper 3 wires go somewhere under the TV/TFT block so I don't knowhere they lead but the lowest wire goes to other side of the PCB(the wire in middle coming from right, going to R610):https://s18.postimg.org/kuuwntrzt/image.jpg
It seems to be connected to ground via resistors(223) and to the t1A transistor(assets.nexperia.com/documents/data-sheet/PMBT3904.pdf#page=3). From the transistor it seems to go to the ic on left: http://pdf1.alldatasheet.com/datasheet-pdf/view/440048/SANYO/LC863232C.html
As far as I understand, it seems to connect the IC's inputs to ground if it's signal is high.
How should I connect the pins (if it’s possible to know with this info) to RCA av cables(or to svideo, doesn't really matter as I wouldt need sound input)? Ask if additional measurements/photos are needed, I can upload them after weekend.
Thanks for help.
https://s13.postimg.org/4tzxayi4n/image.jpg
I guess the TV has originally shipped with an adapter cable connecting the “USB” pins directly to (most likely) RCA audio and video plugs. Something like in https://forum.allaboutcircuits.com/threads/a-v-out-help-newbie-with-meter.63579/ but with different connector.
There are some USB to RCA cables available in eg. ebay but considering overall quality of the product (not very high) I wouldn’t be very surprised if it was some kind of custom design.
Top side of the PCB, the connector on right: https://s10.postimg.org/wjfxb0epl/image.png
Bottom side of the PCB, the connector on left: https://s9.postimg.org/s5eb1og33/image.jpg
The resistors R608-609 are marked 101, R601 is 472 and R602 is 102. I couldn't reliably measure the capacitors but they may be 600nF. Upper 3 wires go somewhere under the TV/TFT block so I don't knowhere they lead but the lowest wire goes to other side of the PCB(the wire in middle coming from right, going to R610):https://s18.postimg.org/kuuwntrzt/image.jpg
It seems to be connected to ground via resistors(223) and to the t1A transistor(assets.nexperia.com/documents/data-sheet/PMBT3904.pdf#page=3). From the transistor it seems to go to the ic on left: http://pdf1.alldatasheet.com/datasheet-pdf/view/440048/SANYO/LC863232C.html
As far as I understand, it seems to connect the IC's inputs to ground if it's signal is high.
How should I connect the pins (if it’s possible to know with this info) to RCA av cables(or to svideo, doesn't really matter as I wouldt need sound input)? Ask if additional measurements/photos are needed, I can upload them after weekend.
Thanks for help.