Author Topic: pce gt recapped sound but no video or control inputs  (Read 520 times)

mario_pic

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pce gt recapped sound but no video or control inputs
« on: April 25, 2017, 05:33:07 PM »
ok need some help i picked up a pce gt used some one tryed to repair it but messed it up  i repaired all the damaged traces  and re capped the system it powers up and i get sound but no video or control inputs

tested the lcd and controls on my working turbo express so its not a bad lcd or a control board

is there a way to find out if system is giving av out  ?  and what ic take tge control.inputs

Keith Courage

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Re: pce gt recapped sound but no video or control inputs
« Reply #1 on: April 29, 2017, 04:48:36 PM »
The only way to test AV is is to do the AV composite video modification.

Have you tested the cap voltages and compared them to the other express you have on hand for testing? Could be some damaged traces.

NichlasEk

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Re: pce gt recapped sound but no video or control inputs
« Reply #2 on: April 29, 2017, 07:35:48 PM »
Or a damaged ribbon cable. I had a small hell fixing one with damaged pins on the main board side. For some reason it needs to be fully atached for video to work (sound is a given, but video why?)

mario_pic

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Re: pce gt recapped sound but no video or control inputs
« Reply #3 on: April 30, 2017, 06:58:34 AM »
figured out video problem turns out some one was messing with the 2 pots on the board  so i get nice video

only problem now is controls dont input nothing at all i tested the lcd and control board on my extra turbo express and it works so it may be somthing on the pcb

mario_pic

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Re: pce gt recapped sound but no video or control inputs
« Reply #4 on: May 01, 2017, 02:24:20 PM »
bump  any one able to help me out  its almost done   just need controlls working

Keith Courage

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Re: pce gt recapped sound but no video or control inputs
« Reply #5 on: May 01, 2017, 03:45:56 PM »
So none of your controls work at all? I've never come across one like that. Even if there are bad traces on the controller board and or shorts in the ribbon cable generally some of the controls still work.

Maybe the ribbon cable itself has a bad power or ground trace as to why nothing is working at all.

NichlasEk

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Re: pce gt recapped sound but no video or control inputs
« Reply #6 on: May 01, 2017, 05:55:49 PM »
When you moved the controll board did you move the buttons? The turbo buttons has been a problem. I had to bend the contacts to make them work. Without them the buttons wont work. But the D-pad should. Maybe sand the carbon a bit?

mario_pic

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Re: pce gt recapped sound but no video or control inputs
« Reply #7 on: May 07, 2017, 12:32:23 PM »
tested ribbon no problems or bad traces control pad works i even swaped my good
turbo express front assembly to make shure its not ribbon 
looks like the pce gt board has a problem now my question is its hard to trace back from the connecter
due to a ground plain on over top  and trace runs a layer under  any o e know the pinout at the ic that the control input goes to so i can back trace it

mario_pic

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Re: pce gt recapped sound but no video or control inputs
« Reply #8 on: May 07, 2017, 04:43:54 PM »
well after checking the pcb under my microscope i found this is the tiny trace causing my controller problems   i scraped back some pcb mask to find a tiny micro crack in trace causing the resistor value to read way off  trace is near the c6280 just under the crystal    now its all up and running  :dance:   now i just need to find 4 long screws to seal it all up