Mazda Rotary Club

General => General Technical => I. C. E. & Electrical => Topic started by: pete sparrow on July 18, 2006, 06:56:55 PM

Title: Curcuit board burnout.
Post by: pete sparrow on July 18, 2006, 06:56:55 PM
Hi
 Hope someone can help. Took the dash out to replace the niddle on my oil pressure gauge,it had fallen off. Replaced the niddle and put everything back in the right places. Turned the ignition on test everything before putting it back together,and smoke appeared at the top L/H corner of the board.Turned off ignition as fast as i could and disconnected everything. As the pics show,two elements have started to burn.The bottom of the two has burnt through in a few places and is marked 8P,going to the centre plug.
 Any ideas why it stared to burn?
 What was the element that started to burn??
 Is it safe to reconnect everything and drive the car?
 Take to any auto electrician or mazda specialist?
 Surely i need a new board and where to get one from?
Cheers
Pete
Title: Curcuit board burnout.
Post by: ro284 on July 18, 2006, 07:07:29 PM
Seems like a short somewhere Pete, But i have often repaired pc boards with damage like that,( on speed control modules,  just by soldering a link wire (insulated) to the nearest solder joint usually a pin through from the other side, cant think whats shorted though,
good luck, Bob
Title: Curcuit board burnout.
Post by: pete sparrow on July 18, 2006, 07:15:48 PM
Quote from: ro284Seems like a short somewhere Pete, But i have often repaired pc boards with damage like that,( on speed control modules,  just by soldering a link wire (insulated) to the nearest solder joint usually a pin through from the other side, cant think whats shorted though,
good luck, Bob
Hi Bob
Thanks for the advice.What type of wire would i use please??
Cheers
Pete
Title: Curcuit board burnout.
Post by: ro284 on July 18, 2006, 07:35:49 PM
Well for my application which are control modules for machines i use 10 or 15amp fuse wire, with an insulating sleeve on, there is no great load generally and even the fuse wire is overkill really, but very succesfull, the sleeve can be stuck down on a bare piece of board to stop if moving about and keep it tidy, very often the most difficult ends are under where the plug slides on, and then i have had to bypass the plug altogether, but you may be lucky, basically you are just bridging the tracks that have burnt away, sometimes though the damage can extend more into a resistor,relay,transistor, on the other side of the board, this could repair the damage you can see, but as i said you will need to trace the short,
good luck Bob
Title: Curcuit board burnout.
Post by: bnaellis on July 18, 2006, 09:47:32 PM
Well if you didn\'t connect any wires to the loom back there, then when you re-connected the plugs you may have one of them the upside down. I think there area couple of the plugs that can fit upside down or down side up if you understand my bad english. If the plugs are connected correctly the there is a losse wire back there somewhere that is touch the circuit board annd shorting it out.
Title: Curcuit board burnout.
Post by: Adriansturgess on July 18, 2006, 10:03:22 PM
That seems quite logical....So repair pcb and put it in the right way next time...:cheers
Title: Curcuit board burnout.
Post by: pete sparrow on July 19, 2006, 07:13:39 PM
Quote from: rotaryimports.comWell if you didn\'t connect any wires to the loom back there, then when you re-connected the plugs you may have one of them the upside down. I think there area couple of the plugs that can fit upside down or down side up if you understand my bad english. If the plugs are connected correctly the there is a losse wire back there somewhere that is touch the circuit board annd shorting it out.
Hi Brian
 Thanks for your reply.I understand what you meant.Tried that,no they only seem to go one way thankfully. There are two wires whch attach seperatly,a pink one and a black,might of got those two mixed,but i wrote it down so i doubt it. Auto electricians i think!?!?!:)