(Topic ID: 282331)

Constant Flashing lights Space Shuttle

By MoFo96

11 months ago



Topic Stats

  • 8 posts
  • 2 Pinsiders participating
  • Latest reply 10 months ago by MoFo96
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#1 11 months ago

So I have been scratching my head on this one for a couple days now. My heat shield light and mutli ball light keep flashing constantly seems to be tied to the tail insert lights in terms of the flashing. As well as having issues with all the other lights on column 1j7-1 besides the shoot again insert any ideas.

#2 11 months ago
Quoted from MoFo96:

So I have been scratching my head on this one for a couple days now. My heat shield light and mutli ball light keep flashing constantly seems to be tied to the tail insert lights in terms of the flashing. As well as having issues with all the other lights on column 1j7-1 besides the shoot again insert any ideas.

lights on when they are not, specially when appear very bright at times, is typically a lamp column problem. Usually it is a blown main driver transistor but occasionally deeper into logic problems.

#3 11 months ago
Quoted from barakandl:

lights on when they are not, specially when appear very bright at times, is typically a lamp column problem. Usually it is a blown main driver transistor but occasionally deeper into logic problems.

i made another post yesterday but i guess that it did not upload i noticed resistor(27ohm 2w +-5%) on that column was blown waiting on new one everything else seemed to be fine but the resistor. its not like the lights flash brighter or anything just constant flashing.

#4 11 months ago

also noticed that when you get the multiplier up to 5x the 6 and 7x are lit but they are dim everything else on the column works just fine.

#5 11 months ago

here is a link to a vid with the issues

#6 11 months ago

Still sounds like lamp column problem. Burnt to a crisp 27ohm resistor is a symptom of locked on lamp column problem, not normally the cause of the problem. The columns are strobed, when it locks always on there is constant load on the 27R 3W resistor that does current limiting on the base of the main transistor and it burns up.

If you replace only the resistor pay close attention to see if it rapidly heats up more than the others. Very likely there is something else still wrong from the PIA, 7408, or transistors. Normally it is just the main driver transistor but with a logic probe you can start at the PIA and trace towards the transistors and see where it locks on at. If you are unsure what to expect on the logic probe compare to working circuits.

Lamp row issue usually end up being all the lights off. Lamp column issues is extra lights on.... in typical fail modes at least.

#7 11 months ago

So after some testing q15 and q24 failed tests. Going to swap them and the resistor and hopefully that will be the end of it. Thankyou for helping me get this far! Ill keep this post updated if the issue is resolved when I get the transistors in.

2 weeks later
#8 10 months ago

So Swapped q15, q24 and r101 fixed all issues I was having thankyou for the help.

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