Hifonics BX1605D repaire

[Perry Babin]

What's the DC voltage on the speaker terminals? Check all of them. I'm assuming that the relay is engaging.

 

[kinser]

the ticking starts first, can just hear it, then the relay engages, and the ticking continues,
plus the ticking can be heard from the amp section, the relay in at the PSU section.
ill measure when i get back from work.

Thanks,
David

 

[kinser]

okay tested output with DMM.. once relay engages, -1.9VDC. and 0VAC..

David

 

[Perry Babin]

1.9v on which speaker terminals?

Black probe on the amp's ground terminal?

 

[kinser]

1.9 volts between pos and negative, the negative terminal if connected to one of the fet rails.. any ways would RCA ground be a good reference point to test?

David

just tested.
Between positive terminal and ground:
2vac, 1.6vdc
between negative terminal and ground:
6vac, 2.9vdc

 

[Perry Babin]

The secondary center tap of the power transformer is the best reference point. If you read 1000 ohms between the RCA shield and the amp's ground terminal (no RCAs plugged in), you should be able to use the RCA shield.

 

[kinser]

thought of the center tap just after i posted the message..

 

[kinser]

anyone?...

 

[Perry Babin]

I think the IC may have simply failed. Power the amp up one more time and push on various points in the board. Does the voltage on the speaker terminals go fully to ground or fully to rail (~80v)? If not, replace the IC.

 

[kinser]

you mean the fet driver? the HIP4080?

Thanks,
David

 

[Perry Babin]

Yes, the 4080.

 

[kinser]

Hey Perry,
i found this thread here about a bx1500 that had same problems and symptoms as mine.
I went ahead and ordered the HIP4080 last night. ill post the results when it gets here.
mean while thank you loads for the help! you are a master!!

Thanks,
David

 

[kinser]

got the 4080 replaced.
powered it up. no speaker or input connected. all good.
powered down. plug in speaker and RCA cable, still no signal source connected.
i turn on, lots of current draw, humming from speaker. disconnect RCA and power up again, no current draw no humming.
now.. plugged in the RCA with an mp3 player. power it up, no current draw thats too high, but no music..

this is complicated..

Thanks,
David

 

[Perry Babin]

If there is no DC votlage on the RCA shield (black meter probe on the amp's main ground terminal), try connecting the RCA shield to the amp's ground terminal with a jumper wire (preferably via a 1 amp fuse). Do you have audio with that jumper in place?

Have you tried operating all of the controls on the amp through their entire range to see if it would pass audio?

Is the relay engaging?

 

[kinser]

kept on testing after i posted the reply, i kept on testing, knocked the board a bit, it would draw alot of current, after knocking around a bit more, the relay stopped engaging.
when i get home from work ill test the rca terminals for dc volts and so on.

thanks,
David

 

[kinser]

okay. relay is engaging again. no current draw.. from center tap to rca ground i get nothing, from batt ground to rca i get -1.4 volt dc.

David

 

[Perry Babin]

It would be best if you installed a 15 amp fuse in the B+ line before you do any more testing.

With the 15 amp fuse inline and the amp on, twist the power transformers. Does that cause excessive current draw?

Does pushing on the board near the output transistors cause excessive current draw?

 

[kinser]

okay.. had a little pop... kinda got a fright!!!
put a fuse in. twisted the transformers and nothing happend. pushed near the output transistors, nothing happend. pushed near the preamp section and got a big spark under the board, and a pop from the speaker. cut power straight away..

 

[Perry Babin]

There may be a short between an uncut lead and the heatsink. Look between the board and the heatsink with a flashlight to see if you see a short.

It's also possible that there is a missing insulator if the amp has an LED board under the main board.

 

[kinser]

it has the hifonics logo lit up.. but that more center board. ill take the pcb out and see what happend under there.. i let you know what has been found.