ive just checked again. With the black probe on the RCA shields those fets are showing some resistance. But when i put the black probe onto the ground terminal and test them again they show 0ohms. Would this be because i havent put the rectifiers on the input board back in? i still cant figure out which setting to use on the digital meter as i get different readings on all settings but nothing came near to 33ohms... it either started off high and started counting down or started low and counting up. thanks
Which FETs, precisely (circuit board designation), had 0 ohm continuity to the ground terminal?
For the resistors/diodes, start with the meter on the lowest resistance scale.
For the resistors/diodes, start with the meter on the lowest resistance scale.
The ones i mentioned before were the ones that were showing 0ohm continuity to the the ground terminal, D501,502,503,504,505,506,507,508. This was checked using my analogue meter set to the lowest resistance setting
its the tabs of the output fets. the rectifiers you told me to take out and test before are still out off the input board.
Since you won't give the circuit board designation for the transistor that was shorted to the ground terminal, post a photo showing (with a red dot or arrow) the precise point where you had the red probe when you read 0 ohms to the ground terminal of the amp.
sorry i did not understand the first sentence :s. im back at uni so i have marked up onto the image from the service manual where i put the red probe:
I had the red probe on the actual metal tabs with holes in them on the FETs
the black probe was on the ground terminal of the amp. This then gave me 0ohms using the analogue meter on its lowest resistance setting.
thanks 🙂
I had the red probe on the actual metal tabs with holes in them on the FETs
the black probe was on the ground terminal of the amp. This then gave me 0ohms using the analogue meter on its lowest resistance setting.
thanks 🙂
Is there an insulator under that transistor?
If so, unclamp that transistor and the other IRF540s in that group. Do you still read 0 ohms from the tab to the ground terminal?
Edit:
When you unclamp them, lift them off of the sink.
If so, unclamp that transistor and the other IRF540s in that group. Do you still read 0 ohms from the tab to the ground terminal?
Edit:
When you unclamp them, lift them off of the sink.
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Help!!
I have a Alpine MRP M500 and the amp light went out and it would not power up. I pulled it from the vehicle and hooked it directly up to the battery and it powered up. I hooked it up in another vehilce and again it refuses to power on. I know the wiring and the fuses are good. Any ideas? Thanks
I have a Alpine MRP M500 and the amp light went out and it would not power up. I pulled it from the vehicle and hooked it directly up to the battery and it powered up. I hooked it up in another vehilce and again it refuses to power on. I know the wiring and the fuses are good. Any ideas? Thanks
right just checked again... i think the insulators may have moved alittle when i installed the new FETs on that board. They all show resistance of about 0.25m ohms now with the digital meter set to 20m.
Reinstall the positive rectifiers, clamp everything down and power up the amp. Do you still have significant DC voltage on the RCA shields (black probe on the chassis ground terminal)?
Hi Perry, ive reinstalled the rectifiers. I didnt get time to power it up today but i will do it next weekend when im back from uni. thanks for your patience. 🙂
right just powered it up. The digital meter showed 0.73v on the RCA shields ( black probe on chassis ground terminal and red probe on RCA shields). Also the music and power light are showing solid green and the protection light is flashing red.
It sounds like it may be working normally. You'll have to connect it to a head unit and speakers to know for sure.
okay so should i check with 15amp fuse in the current 8gauge wiring i have in the car and connect a sub to it with the RCA's connected?
Woohoo! i just tried the amp with the sub and it works!! all green lights! thank you so much perry! appreciate it!.
...Could i ask for one last favour though please?... im running a dual 2ohm alpine type r subwoofer and currently it is wired to 4ohms, what setting would you reccomended to set the parametric equalizer and the gains etc?
Thanks again for your help! 🙂
...Could i ask for one last favour though please?... im running a dual 2ohm alpine type r subwoofer and currently it is wired to 4ohms, what setting would you reccomended to set the parametric equalizer and the gains etc?
Thanks again for your help! 🙂
All of that depends on the vehicle, enclosure, woofer and you're listening preferences. You should begin with a crossover frequency of ~90Hz and all equalizer controls set to 0.
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