Boss 4800 d

No i have not work in it, i Want to solve the PS issue first
I do not remember if i told you, but i installed only four PS fets instead of 16 in total One per bank(two toroidal transformers), if i install all output fets should i install all PS fets, or maybe i should fix completelly the PS with all 16 fets before i can go to output stage.
Im powering the amp with 12 v@3 A and when the amp is starting aparently there is not enough current because the fan starts and stops three times before keeps running stable
 
I think i partially solved the PS problem the transistor tha trigger the d600k Was bad(like two diodes) i replaced and the amp needs 12 volts in remote to turn on.

Could some one tell me if this model is diferent in the behavior of the Leds at the starting process???, i ask this because when i put 12 v in remote, the green led flashes three times and then stays On, when the green led stops the flashing i have rail voltages( 70 volts) , but the red led never turns On, i checked the red led and is Good, if this condition is not normal i Want to solve it first, so i can go to the output section.

Thank you
 
Have you solved the PS problem?

Have you tried installing all of the outputs to see if all get hot equally or if the amp draws excessive current?

There could be a problem with the idle current through the CCS but that would be almost unheard of with the amps that use the 31N20D.

Perry i fixed PS copletely now the amp starts normally with red led first goes off about 3 seconds and the green led ligths inmediatly after the red goes off, the lm393 comparator,involved in protection cuircuit Was bad. I replaced with a New one

The CCS i do not Know what it means, could you please tell more about it, and how i can check if this is the cause of the heating
I installed the New mosfets an this gets hot like the used ones, i turned the amp off when the positive mosfet reached 60 Celsius without clamped to amp, the negative rail mosfet Was about 4 degrees cooler, could this diference in temperature be a clue of what the problem is?

I Was thinking in trace the audio path, an see if the dirtortion is produced in the driver board or Back in the other circuit with op amps jrc4558, in part the fast heating of Fb31n20d could be the excesive distortion or not?
Other thing i could do is install a caps instead a Fb31n20d an trace all the audio signal, i feel blind without a Good scope.:(
Another thing i díd Was change the op amp with a 4580 the board originally has jrc4565, nothin changes with the swap
At this point i'am lost.
 
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Thank you! I have replaced in the driver section q42a q43a q44a( the old ones got so hot, this New ones gets hot too) réplaced too q47a q46a, q36a,q35a, q49a q37 a and the op amp, checked resistances values all seems ok, i think there is something bad with this driver circuit but can not find the problem, i conected audio in rcas, and connected a 6 ohms subwoofer and the audio plays distorted. I have not checked the caps.
 

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Page 6 of the following page has a diagram that's close. The circuit board designations on your board have an additional A suffix.

http://www.bcae1.com/temp/classDtype2wdriverboardindexa998.pdf

On the diagram, Q37, ZD7, etc form the CCS. To reduce the idle current, you typically increase the value of R95 slightly. Only do this after you've confirmed that all other components are OK and the circuit is working properly. It's almost unheard of for this to be necessary on the TO-220 versions of these amps.
 
I'm no shure why, but the distortion has gone, i only replaced one a56, i have no changed it because with the multimetter tested ok.
Now that i have a clear and nice sound, the 2 output mosfets installed keep heating the same, but now i'm going to install all 12. Fb31n20d and monitor if the heating is equal i Was thinking in clamping the mosfets and monitor the total current consumed @ 12 volts.
Perry in your experience, what current at 12 volts for thos amp Will be considered normal with no audio input??
 
The amp is working fine, all psu and output gets installed and clamped.
When the amp is starting(red led On) the amp draws 1.46 amperes, when the green led turns On it draws 3.4 amperes at idle, i put audio and hear about 8 min of music at a modarte volume the amp gets little warm.
I lefted the amp On at idle for about 2 hrs and i feel the amp warm.

What do you think about 3.4 amp at idle for this amp??
It sounds nice, for about 10 second i demanded high power to the amp and worked nice.
I turn it off an On several times to see if the current Was the same in all the times i started, i got exactly the same
1.46 amp red led, go up to 3.4 amp green led
 
Hi this amp has worked great some rime, but few days ago, it begin to smell weird the amp got hot, but not so much, I opened it and disco er two caps bulged and the bad smel is the dieléctrico coming out of the caps, I looke for the same caps but im having trouble Because they are 30 x 30 mm y find 25 x40 they do not fit
I think in in adapt a bank of caps in parallel configuration, do you think is a good idea I want more voltage. The voltage rails is 70 volts and the original caps are 80 volts 105°c 3300 uf
I want something lik 3 caps of 1000uf 100v
I apreciate your opinion