Shrkamp 2500.1d help

[rhempz01]

I removed and replaced all 50n06 with 3205,s 47 gate resistors that where out of tolerence. I have one ps fet that keeps showing a strange short? I cant fiqure it out. Are my regulators shorted? Mur2020,s all the outputs test ok no shorts. Driver board is removed module 2

 

[Perry Babin]

Are you saying that one PS FET keeps failing?

Does the amp work normally with that FET out of the circuit?

Do you have a broken or intermittent connection between the gate resistor and either the drive circuit or the FET gate leg?

 

[rhempz01]

I havent tried without or powered it up perry. Just gets a array of beeps when two legs are touched. Ill check the gate resistor. I did replace a few that were out of tolerence.

 

[Perry Babin]

The drain and source legs are directly connected to other FETs so unless the connections to those legs are broken, they can't read differently than the parallel FETs.

 

[rhempz01]

Ok perry thanks.

 

[rhempz01]

Indeed some 3205 are no good. So i replaced the banls with tested ones to insure they are simular and working now all are reading the 10.1ohm 1-3. So it powered up. Quick question. I need a completly excellent method for discharging caps, i used a resistor and think they are discharged only to get a pow!! Somewhere and it hurts my ears!! Especially on large amps. I dont care the cost i need a cuurcuit design or a safe method

 

[rhempz01]

I can't seem to get 5.58v on one of the banks on my gates? I replaced every thing on the driver board. Still nothing. The regulators are still in the board. All the rest are spot on. Anyone have an idea what I should check?

 

[NadaD]

It draws any current?
I would start with PS PWM driver voltages.

 

[rhempz01]

I got them all to work I have 5.58v on every gate. It was broken price of trace from the driver board. I changed every component on the driver board with more reliable transistors. Just waiting on my 50n06's and I should be good.

 

[NadaD]

IRF3205>50n06

 

[rhempz01]

Use the 3205 nada? Gate resistors will work with them there 47ohm. This is where I'm at no regulators. No ps fets the amp Powers up and I got 5.05v on the gate pads.? This sound correct to anyone.....?

 

[rhempz01]

Now

 

[NadaD]

3205 wil work perfectly with 47r gate resistors.
I wouldnt trust only on multimeter readings, it indicates that there is drive signal, but you cant see if its correct and good shape - oscilloscope needed.

 

[rhempz01]

I ordered some from mouser. I have a scope. I should get a nice sqaure signal. It's just analog and honestly in not that good with it. But I get a signal it just a =======looking signal...I can upload a photo if you could help me with it?

 

[NadaD]

Check all gates of all banks. Post photo.

 

[rhempz01]

I don't get any square wave only a straight line with noise on it. Is something on the board wrong? Is that the only components that control the gate signal?

 

[rhempz01]

Driver board I replaced all the transistors on this board. With the correct transistors I believe. And the 494. I only didn't change the. Q50, q49, q48, and q23 at the top of the board but the drivers I changed. Can I use different one a06, a56 if I use the 3205's? There is m6 and L6 in there now

 

[rhempz01]

Most I get is this?

 

[rhempz01]

Ok so I changed a few other chips on the ps driver board and get this. But it still does not have a perfect sqaure? Can anyone tell me if this is ok?

 

[NadaD]

This looks OK!