RF Prime R500-1d help identify components!

[ray9043]

Hi everyone! Im trying to fix a Prime r500-1d, 2 months ago i fix a Jl jx 500/1 is the same board and has the same problem, the ic mp18021 is blown, but this one has the board very burnt.


Anyone here has a good quality Pic of the board? I foubd one but i cant read the resistor values and the tracks.

Thanks!

 

[Perry Babin]

jl amp

 

[ray9043]

Thanks men!!

 

[ray9043]

Hi Perry , do you know the diode value for D12 location? Its in parallel with the 33ohm resistor on each MOSFET gate.
Other doubt, the pin 3 of the ic DVRH is tied to ground or where is tied?

Thanks

 

[ray9043]

I found d15 and d16 in short, labeled l4w, schotky barrier 30v single diode. I cant find It!! Can i replace with 1n5818? Both are 30v schotky diodes.

 

[Perry Babin]

Not 100% sure but the diode is likely a 1n4148 type switching diode.

One drv goes to one bank of FETs, the other drv output goes to the other bank of FETs.

 

[Perry Babin]

BAT54 is readily available.

 

[ray9043]

Ok, i live in México, very hard to find smd components, i Will look on some amp boards i have around.

 

[Perry Babin]

Digikey and mouser likely ship to Mexico.

 

[ray9043]

Hi! Bad news, i put new mp18021, and the schotky diodes, now the 494 is off, i try to replace the lm358 with no luck. If i tie the pin 16 of the 494 to ground, pwm signal appears on the Gates. Any ideas?

 

[Perry Babin]

Are the FETs in the circuit?

 

[ray9043]

No, i pull out all ps fets.

 

[Perry Babin]

Try installing the FETs if there are no shorted outputs.

 

[ray9043]

I try with 2 inexpensive irfz44, one un each bank, and they burnt out.

I read 1.5v on each Gate, constant voltage.

 

[Perry Babin]

Did you have the 1.5v before installing the FETs?