Diablo Audio

[blazer40]

Where was your negative probe when you took these readings?

 

[oldguyoklahoma]

neg batt terminal on amp

 

[blazer40]

Perry is right, that IC isn't getting enough power. When you power up the amp, what is the current draw of the amp? (I'm curious if you have something drawing more than your power supply can put out, hence the low voltage on that IC)

 

[oldguyoklahoma]

. 0025 amps at no remote, after applying remote 0.176amps. source voltage is 14.6 volts. LOL Thanks for your attention to detail there blazer. And i am laughing at the situation.(mine). You would laugh too. I am not your average tech. My learning process is different than most.

 

[blazer40]

Good, at least we don't have a short that is drawing the supply down. Pin 12 of that 494 IC is power for the chip, trace it back (to usually the remote) and find out what is preventing power from getting to pin 12. I usually find there's a blown transistor holding up things....

 

[oldguyoklahoma]

What are the components that I have in the yellow squares?

 

[blazer40]

The bigger items on the heatsinks, I don't know, what are the markings on the front of them? The two smaller items are resistors, looks like they got hot. You'll want to verify their resistance because they have burned some. (I can't quite tell their value from the pics)

 

[oldguyoklahoma]

i cant make out the colors on two. there is actualy four that are burnt.

 

[brandes.cm]

The one with the brown band is 10ohm and the other is 4.7ohm I believe. Yellow, violet, gold, gold

What was the failure mode of this amp, over voltage?

 

[oldguyoklahoma]

completely dead.

 

[oldguyoklahoma]

under voltage. stock electrical on a .5ohm load

 

[oldguyoklahoma]

it died due to underpower. too much load.

the man had it on stock electrical in his car and on a half ohm load.

 

[oldguyoklahoma]

under powered. on a .5 ohm load

 

[oldguyoklahoma]

these resistors also got hot and I am not getting voltage through the one on the end.

 

[oldguyoklahoma]

Sorry bad editting on the picture. repost

 

[oldguyoklahoma]

Fixed... was the switch mode controller. Thanks everyone. Perry your video is great.

 

[Perry Babin]

Glad to hear that you received it already. To clarify, it's not a video. It has a few video clips but it's mainly text, graphics and interactive demos.

 

[oldguyoklahoma]

Yes I stand corrected. The tutorial is very informing. Sorry Perry.
And on another note the amp is down again. something is causing a short circut after it played for a hour. it blew the small fuse that i had on it. And after calling the owner he said that he was driving without the stereo on and the amp blew. I cant find anything that is shorted. But when I ohm it out with my meter it shows short circut. I pulled all the power supply fets back off they all test not shorted, pulled most of the caps off and none so far test bad. the rectifiers all show good. Any more suggestions????

 

[oldguyoklahoma]

As you can see I have stripped the back half of the board. I may have went too far but getting frustrated.

 

[Perry Babin]

When you say it appears to be shorted, PRECISELY where were the individual leads, what was the meter set to and what was the meter reading?