BX1000D with no output?

[79twotone]

I know alot about car audio but repairs is something I've never really done, but I'm sure I can find an explanation on the forum. I have a HiFonics BX1000D that will power up but has no output. Also when connecting the power there a pop from the amp. I've taken the back off the amp and it looks like a few things overheated. And I couldn't get any pics but found a few other post with the same exact problem with pics. So I'm guessing maybe its a design flaw. But this is a decent amp that I'd like to repair. Any help would be much appreciated. P.S. I tried to get schemematics from maxxsonics and was told they could only be released to there authorized repair shops.

 

[79twotone]

second pic

 

[Perry Babin]

Have you checked the output transistors to see if any are shorted?

 

[79twotone]

Thanks for the quick reply but like I stated this will be my first repair so I'm guessing that the output transistors are the things that are fried on the board. I apologize for my lack of knowledge.

 

[I Am An Idiot]

The blown up pieces are the power supply transistors. The outputs are on the other end of the amp.

 

[Perry Babin]

You said these photos were not from your amp. Did the power supply transistors (those near the power and ground terminals) fail in a way that caused physical damage (cracked or smoked)?

The output transistors are going to be near the 20 pin IC in the socket. They are in 4 groups of 2.

 

[79twotone]

No the pics aren't mine but it is the same exact amp and what mines looks like on the inside. I apologize for the misunderstaning. There's only damaged parts were the power supply transistors. On both the top and bottom (looking at the pic). 4 on the top have smoked including one that cracked. And 7 on the bottom also smoked with one that cracked also. I'll try to get a pic up with the covers removed.

 

[Perry Babin]

From the photos, it appears that there are 8 power supply FETs (4 on the top and 4 on the bottom -- all on the far right end).

There are eleven 3-legged semiconductors on the bottom row. Numbered from 1 to 11 from the left to the right, which ones show signs of damage?

 

[79twotone]

On the top all 4 look like they smoked with number 2 cracked and 3 and 4 look to have begun to start melting. On the bottom again the first 4 smoked, 1 and 3 started to melt and number 2 cracked. Again thanks for your help.

 

[Perry Babin]

If the 4 on the bottom left have failed, you must replace them and the HIP4080 IC (in the socket). Although it's possible that the other 4 output transistors (top left) have survived, I'd strongly suggest replacing them (even if they check good with a meter).

All of the power supply transistors (the 8 on the right -- 4 on top and 4 on bottom) must be replaced. You need to check the gate resistors (connected to pin 1 of the power supply transistors).

The driver transistors may also need to be replaced in the power supply. If I'm not mistaken, there is one driver just below the transformer. I can't see the other. The first leg of the driver transistors will go to the gate resistors. You'll have to locate them or provide a better photo.

 

[79twotone]

Actually all of the output transistors look fine, but all 8 of the power transistors are fried. But I think I'll take your word for it and replace them all just to be on the safe side. Still waiting on a response from maxxsonics to find out what model power transistors they are. I'm guessing there TIP41C, because the numbers on the transistors weren't found on any of the electronic parts sites. Thanks again...I'll still try to get some pics up by the end of the week.

 

[I Am An Idiot]

They may look like a TIP41 but believe me they are not. What are the numbers on them that you can't find on your electronic parts sites?

 

[79twotone]

This is just just what one of them says...F M()339 F()P 65N()6. I'm guessing that they could be 0's or Q's but they're just ()'s on the transistors. I found a FQP-65N06 part number for mosfets. Maybe thats what they could be.

 

[Perry Babin]

The FQP65N06 is a commonly used power supply transistor. Mouser has them.

I suggested replacing the outputs earlier but after reading your more recent posts, I'm not sure which transistors have failed (other than the power supply transistors). Don't replace any parts until you've done more troubleshooting.

 

[79twotone]

Yeah its kind of hard giving info without pics, but I'm away from my digital camera until the end of the week, and cell phone pics are crappy. But thanks again for the help. This is truely a learning experience.

 

[79twotone]

Its been a while but between school and work, I haven't had much time to work on the amp but I'd still like to try to repair it. Here are some pics of the amps internals, oh yeah and sorry about bringing this post back from the dead

 

[Perry Babin]

Did you check the output transistors to see if any are shorted? They are the ones on the left (4 top, 4 bottom) in the overall photo of the amp.

 

[79twotone]

I've actually only checked the obvious so far which were the FQP65N06's which were the ones that were damaged. The output transistors(F1310N's) which I'm guessing are the ones at the other end of the amp look fine. After reading through one of your old post you said I may need replace the FQP65N06's and the HIP4080 IC

 

[Perry Babin]

If there are no shorted output transistors, the HIP4080 is probably OK and won't need to be replaced.

You also need to remove and check the PNP driver transistors. One is between the transformer and the power supply FETs. It's D-shaped (looking at it from the top) and is adjacent to a diode and resistor. I can't see the one on the other side. You need to pull both of them and check them. If you don't know how to check them, use the form below and post the screen caps (instruction in the panel at the left of the form).
http://www.bcae1.com/repairbasicsforbcae1/images/transistortestpage02.html

 

[79twotone]

When checking the transistors using your page would I be checking each one all six ways recording the values for each?