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Hello again, Been slowly getting a MTH New Haven FA-2 ABA set with Proto 2 5V system fully rebuilt to hit the rails again.

Model number: 20-2238-1

Last piece of the puzzle is the trailing A unit's smoke unit not heating up. I rebuilt the smoke unit with a new motor and it spins great, but no heat is made at all. Closely looking at the slave board, the left leg of the smoke FET has some white discoloration.

Testing either smoke resistor solder pad, to any of the smoke unit Phillips screws DOES draw about 8 ohms.

If I disconnect the 4-pin harness (with purple smoke wire), the short goes away.

The oem heating elements are in great shape and ohm out correctly to 8 ohms (2x smoke resistors together).

Does this sound like a cooked smoke FET? Part: 3055L SOT-223?

My last question, can I test a ps2 5v slave board independently on my mth ps2 test fixture set?

Thank you for reading, and the help! The wealth of knowledge here is incredible

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Last edited by p8ntballer789
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@GGG posted:

Your element is grounding out to smoke housing.  Does it have the insulator inside?  Make sure elements not touching side of housing.  FET looks fine.  You need an adapter cable to test a slave board with test set.  G

Thank you! I will double check the elements and housing today after work. There was a super thin white/clear insulator that cameout in a few pieces. I can't find it on the parts site but still browsing. Thank you! 🙂

You also need a 3V PS/3 board or a PS32 with the 3V connectors.

Apparently, the slave harnesses are out of stock.  I'm guessing that's probably a permanent condition since they've moved on years ago from the master/slave architecture.

Thank you John! I have been putting your old test fixture to good use! Had a feeling there was a special way to configure the slave board for testing haha.

Thank you John! I have been putting your old test fixture to good use! Had a feeling there was a special way to configure the slave board for testing haha.

Yep, you have to cable the slave board and the master to the test harness to exercise the slave board  I suppose it would be possible to build one of those cables, but for the few times you'll run across a slave board, one wonders if it's worth it.  I bought the cable when they were still in stock.

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