*HELP* Troubleshooting saz-3000D protect

[Rawr-DQ 10+ year member]

unfortunately, after re-installing my car audio I found my sundown amp going into protect.It goes into protect immediately; the power light turns on about 1-2 secs later; 5 seconds later the two relays marked with a purple X close/open(click)...; unhooked from speaker; I found manufacture damages that were covered in glue, marked in black; red. In pink there is some rubbing damage to the winding; no metal caps blown; the plastic ones which the top may have some give; each one can depress at-least a mm or so. That's all I can tell visually. I cannot smell burnt electronics; nor are any burns prevalent on top of the board.I've built small circuits and studied them a lot; and have a megger which probably wont be needed; along with a 400mfd/~2Mohm range; and MV Meter... I also have an oscilloscope. So please help get me to a starting ground on repairing this amp; I have good soldering skills. And can re-paste the transistors tot he heat sink with high quality thermal compound.Pictures are large for detail...

yellow rub; black manufacture damage

yellow rub; black manufacture damage

all manufacture damage; have glue over it; yellow insulation missing on wire; black minor heat shrink overheated.

X's represent relays turn on/of after 5 seconds.

Click to read more...

 

[Rawr-DQ 10+ year member]

In yellow rub; pink manufacture damage

I did some testing; I have a 12v powersupply thanks to a optima d31a; 1125 cranking amps; 900 cold; 75 amp hour battery just sitting around...I did millivolt testing From the positive terminal; I can measure hundredths of a millivolt; I got ~29mv on exposed windings closest to the power in. ~5mv on each heat sink. marked in green I have 102 volts.Any ideas where to start; can someone help me trace the protection circuit?

 

[disturbed471985 5,000+ posts]

Ill buy it on te cheap and fix it and you buy back at a higher price what u think good idea?? Just BSing hope it wrks out. Sill under warrenty?

 

[Rawr-DQ 10+ year member]

nah I doubt it; i've had her for years

 

[disturbed471985 5,000+ posts]

lol its was just a joke so its an older amp?

 

[hispls 5,000+ posts]

Strong odds it's something that has nothing to do with what you have pictured. Any semiconductor on that board could be hosed and not appear visibly damaged.

 

[Rawr-DQ 10+ year member]

well I don't mind pulling and testing them. But I need a basis on how the protection system works; and how many variables, chips, and circuits could be involved?

I have 102 volts but no power out and don't know if the protection system is analog or digital, however I don't see many chips and will probably pull it and check every transistor for cracks or other overheating damage

 

[Timmothy Web 10+ year member]

can u take a pic of the ps drive circuit?

 

[Timmothy Web 10+ year member]

check the ps and output transistors for shorts.

 

[Rawr-DQ 10+ year member]

 

[Timmothy Web 10+ year member]

let me know what u done so far.

 

[Rawr-DQ 10+ year member]

thanks for the help; i pm'd ya

 

[Rawr-DQ 10+ year member]

Checked all mosfets

Tim your pm box is full

 

[Timmothy Web 10+ year member]

pm me now