MV1C no signal

[Jarryson]

Hi all,

I have a problem with a mv1c.

Before consolize it, I tested the board and worked fine. I installed Unibios in socket and worked fine.

I consolized it, I installed controller ports and video output.
I installed a reset button, but I used (I dont check the button) and it was NO (normally open) so the board (I think) always was resetting.

Tested and not working. No signal all time in my tv (tested in 2 tvs).

I have desoldered all (controller ports, uninbios, reset and video output) and now doesnt work. I am testing it with a supergun.

I have 5.11V in all Vcc board pins.

D4990 pin 10 is high and pin 11 low.
Bios pin 40 no signal in my probe. All traces have been checked and all is ok.
No signal (with proble) in 24Mhz crystal pins. (Crystal replaced and same issue)

I dont understand what happened...this board was working fine...

Board is in perfect condition, no bad traces or leak, no cuts or shorts.

 

[Jarryson]

Nobody?

 

[aha2940]

Nobody?

POst pics of the mods you did. Or try undoing them, maybe you connected something wrong that is avoiding the board to work.

 

[Xian Xi]

How did you install a reset button exactly?

 

[Jarryson]

POst pics of the mods you did. Or try undoing them, maybe you connected something wrong that is avoiding the board to work.

Hi,

all mods were undone and the problem is the same.

I consolized the board and all work fine before consolize. But when I tested it consolized, reset button wasnt connected.

Board hasnt any bad trace , cuts or shorts. I will post some pictures.

How did you install a reset button exactly?

Hi Xian,

for reset button I used your tutorial in JMX. I soldered a cable in 7045 leg 2 and other cable to Gnd. But the button/switch I installed was Normally open, so it was always "reseting".

 

[kaicer]

Maybe is a blind shot but should check if not done for solder bridges on the board and IC legs. Sometime a little blob of solder could get in places you don't notice.

 

[Xian Xi]

Hi Xian,

for reset button I used your tutorial in JMX. I soldered a cable in 7045 leg 2 and other cable to Gnd. But the button/switch I installed was Normally open, so it was always "reseting".

I'm guessing you mean the button was normally closed as that would cause resets since the button is grounding the reset line. Normally open is like a normal state of a button that needs to be pushed to activate the command.

Post some good pics when you can of the consolization. So when you power on, screen is just black? Did you check the hard dips to make sure you didn't flip #8 by accident?