HEQ5 reverse polarity repair

[kerrylewis]

I am preparing to tackle my fried HEQ5 and am wondering if anyone has actually carried out a repair following the dreaded reverse polarity?

[knobby]

Good luck ...

All I can suggest is to look at the components near the power connector with a magnifying glass carefully, hopefully there will be a diode that has 'blown'

Try metering it , it should be open one way and closed the other.

[kerrylewis]

Thanks Knobby for this and the reply in the other thread. Anyone else tried it?

[knobby]

Fingers crossed... I seem to recall that they don't use any form of reverse polarity protection so don't hold out much hope , but with any luck... Something will have burnt out (visibly) before the juice got anywhere important.

[Fred_76]

I had that experience once on my brand new HEQ5. First connection and pshhhhh... The power block had reversed polarity due to a misconception of the fabricator (a well known brand indeed). They paid for the replacement of the HEQ5 motherboard.

But I had time to check what components burned : mainly capacitors.

When I received the replacement motherboard, it was not the one that burned but still a repaired one : I could see the recent work on the soldering. Only capacitors were replaced : all of them.

Therefore I suggest that if you start by replacing the capacitors, you should make it work again.