U need to find the left turn driver tht couples to the H bridge gate.

If the rght turn works and the left turn traces were fried then it is possible tht the driver might be fried too

The driver is a dual and controls both sides, it is an MIC5016bwm. But before I start farting with a 16pin replacement, I'll check the other transistor. That's why I'm asking about the circuit I posted and which transistor is a 'teammate' of the one I replaced ( Q9 ).

Don

 

Can you tell me which transistors are working together in this H-bridge?

What I'm really looking for is which transistor is on at the same time as Q9, since the autopilot is behaving exactly the same now as when Q9 was blown up ( prior to me replacing Q9). I'm thinking that it's teammate might also be broken, but without any visual signs.

Thanks,
Don

Ok Don can you have a look at the track at the top of this photo. Is it connected to + or - or one of the motor terminals ? It is possible it may be connected through a Low Ohm High Watt resistor.
I did warn you very early in this thread that it was very likely that you had two damaged transistors. Currents always keep going until they complete a circuit.

 

Ok Don can you have a look at the track at the top of this photo. Is it connected to + or - or one of the motor terminals ? It is possible it may be connected through a Low Ohm High Watt resistor.
I did warn you very early in this thread that it was very likely that you had two damaged transistors. Currents always keep going until they complete a circuit.

If you look at the picture on post #37 of this thread.

http://forum.allaboutcircuits.com/c...acock_photos/AutoPilot-circuit/Backlight1.jpg

Lower right corner, the small rectangular component above the blue capacitor has markings 33 20v on it. The trace you asked about, connects to that component, the big blue capacitor and the L2 resistor, then over to the fuse area (where the power comes from ).

Thanks,
Don

 

On your board each pair are back to back that are likely to be affected.

 

OK so you are saying this is connected to +

Then the tracks 1 & 2 labelled in red in the attached photo will be going to the two motor terminals labelled Black & Orange on the pic on post 37. Can you check for continuity on the board to verify this.

If so the paired transistors are diagonally opposite one another like an X

i.e top left & bottom right in attached photo are on together in one direction and top right and bottom left in the other direction

 

If the picture posted by you is correct, I tend to agree with cork ie that the paired transistors are connected diagonally like an "X". Q9 would pair with Q12 while Q10 pair with Q11.

Allen

 

Yep and U12 is most likely a quad or hex inverter.

 

Thanks guys,

I have a finer point for my soldering station, some de-solder braid and flux on order.

Should have it all by the end of the week and then I'll swap the other transistor and give it a shot.

Thanks again,
Don

 

I thought I did not made my self clear in getting some braid and all tht to clear out the solder...!

Was it the way I said it ?

 

I thought I did not made my self clear in getting some braid and all tht to clear out the solder...!

Was it the way I said it ?

I understood what you said, I took your advice and ordered some (after I spent 3 days looking for the roll I bought for another project a couple years ago).

Now that I might be ripping all the components off the secondary board and testing/replacing more than just a single component, I needed to get a finer tip for my soldering station, especially if I need to replace an IC.

Don

 

What was the final outcome on this?

Did you get your autopilot up & running?

 

I am interested on how's your auto pilot's present condition too. Is it working now?

Allen

 

Perhaps he is lost at sea?

 

Without the auto-pilot or the auto-pilot malfunction functioned again during the trip. Hope the GPS and communication system are working......

Allen

 

its a shame he never came back with feedback. i also have a tr1 that is starting to act up. it acts erratically under 60 degrees. once it warms itself up its just fine. ive taken to putting a heating pad on it on cold mornings just so it doesnt beat itself to death. what would make it do this? i am loathe to tear it apart until after the season so ill probably be back in the fall. meantime, who knows? maybe the original poster will get notified and chime in.

 

Don't hold your breath!

They make cooling spray that can be useful for localizing a temperature-related problem. Make the board warm enough to work, then spray to cool different components and see which one, or which area of the circuit board, causes a problem.

 

Could be cold solder joints.

 

Necroposting, revival of a dead thread, is not allowed on AAC. You would normally need to open a new thread, and reference the previous thread if it really pertained using a link.

Which brings us to a second problem. We are process of changing the rules here, but we did not allow discussion of transportation vehicles. This could change, it might not, it is very much in the air at the moment.

Sorry about that.