I have a mth scale up challenger I went to start up the Challenger and nothing happened completely dead. I checked the circuit board and number Q 76 looks like it’s burnt. Is this going to be an easy fix by changing only that part or not. Does anybody know what that part is The markings on the part are C8DZC. 
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I'm just going to say, that board is likely dead. I'm not saying you cannot try to fix it, but experience says, when PS3 dies and blows a transistor, and doesn't power on- that transistor alone is not what is stopping it from working. No, more likely, that component failed, and when it failed it allowed power back up the gate into the control circuit- and may have blown many other chips on the board not even yet apparent. In electronics- you don't need physical obvious burn marks to kill a chip.
More important than ever- finding out why it died in the first place- typically a pinched or shorted wire to frame.
Just checked a brand new board with a magnifier, that part Q76 is labeled c8CGA and the middle C has 2 lines or dashes under it.
Some searching, and no guarantee on this being correct, many smd parts use the first 2 numbers or letters as the code
https://www.vishay.com/docs/72322/si2318ds.pdf
Si2318DS
N-Channel 40-V (D-S) MOSFET ?
Are you watching current draw when starting up? That chip is a coupler chip. So check rear coupler for short/damage. G
You got it right checked the coupler sure enough it’s burned out wondering if the coupler caused the problem or the board . And if I change out the mosfet will this fix the problem. I’m thinking the board is fried. What do you think? 
Does mth sell the board I need? Does anyone know the model number of that board?
@TheSteve posted:Does mth sell the board I need? Does anyone know the model number of that board?
https://www.mthpartsandsales.com/
You need to know the revision and if they are EMI compliant variant of the boards. This matters because if you boiler board in the engine is one version, ideally you want matching versions and there is a chain file firmware difference and that can matter.
My advice- send it to a tech capable with a PS3 test set and ways to check your entire system of both engine and tender such that you don't just buy a board and put it in, only to what it blow up again.
@TheSteve posted:You got it right checked the coupler sure enough it’s burned out wondering if the coupler caused the problem or the board . And if I change out the mosfet will this fix the problem. I’m thinking the board is fried.
What do you think?
It could have gone either way. The coupler could have failed and caused the FET and board failure, or it could be the FET got stuck on from some other problem and that cooked the coupler which then further fried the board.
Again, your best bet in such a scenario is not to fire the "parts canon" and empty your wallet at a failure. Instead, pay an authorized and experienced service tech, have them test your boards, and have them take the risk of the repair.
It's one thing if you know 100% how and why a failure happened (example an obvious pinched wire, a shorted smoke unit) but when you get into this "not sure" situation, you run the risk of replacing a board- only to watch the new one go up in smoke.
FWIW, a discussion on EMI VS non-EMI board sets
Remove chip and test board but chances are it is dead. You can order the non emi board, and load flash and sound file for your engine. It will work with the boiler board if it is good. Should be.
Or send boards to tech who can test repair. Load files including the serial data (engine name) which only tech can do. G
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