Hitachi HTA-DD3W AV Receiver Error Code -Protect-

[CdDvdFlash]

I have a Hitachi HTA-DD3W AV receiver and when I got it I tested it working fine with speakers but it needed a clean inside because it had signs of moisture in it but it was fully dry with bits of wood chips, I guess this was left in a shed so I fully disassembled it and cleaned it with isopropyl alcohol very carefully, some de-soldering was also needed but now its very clean, luckily there was no rust on any components and all the capacitors are fine with no bulging. When I turn it on I hear a relay switch on then a few seconds later another relay switches on or off and the display has a "-PROTECT-" error code so I switch it off and try again and its the same error. I would like to remove the board with four blue relays in the middle of the amp this board is for the speaker A+B output and in the manual it mentions there is a protection layer for the speakers but can I remove this board and test if the error code "-PROTECT-" goes away or would taking a board out and powering it on cause damage to something? The picture below with all the I/O boards removed is how it was before I cleaned it to show why I think it had moisture at some point.

[CapLeaker]

Re: Hitachi HTA-DD3W AV Receiver Error Code -Protect-

Resolder the 2 brick modules mounted to the big heatsink. Have a good look on anything heavy like transformers and anything that gets hot and is mounted on a heatsink and other components and resolder them as well. If it worked before, it should work now.

[CdDvdFlash]

Re: Hitachi HTA-DD3W AV Receiver Error Code -Protect-

Thanks CapLeaker I'll try that too do you know if it's OK to remove one output board at a time and power it on, a sort of fault finding?

[CapLeaker]

Re: Hitachi HTA-DD3W AV Receiver Error Code -Protect-

well the protect mode is on, because it senses DC on one of the speaker outputs and the relay doesn't engage the output to the speaker terminals.

With amps that have these brick style modules, 9 times out of 10 it's a bad solder joint. Take some flux and fresh solder and redo those 2 modules and it should come back.

Removing one brick at a time for testing may not work, as some speakers would be missing, which makes the PA go in Protect mode again.

[petehall347]

Re: Hitachi HTA-DD3W AV Receiver Error Code -Protect-

try without speakers connected

[CdDvdFlash]

Re: Hitachi HTA-DD3W AV Receiver Error Code -Protect-

Ide just like to say thanks CapLeaker, I resoldered the 2 brick modules and some mosfets (or power regulators) and a couple of dry joints and it's working again

[CapLeaker]

Re: Hitachi HTA-DD3W AV Receiver Error Code -Protect-

Perfect!