HELP!!!!!!!!!! MY alpine MRV 1507 damage. any 1 can help me?? pls.

[jasyip5052]

35V for both

 

[Perry Babin]

Was one a negative voltage?

 

[jasyip5052]

sorry Perry, jst now i got nothing to do when still waiting your reply, i try to rmove all the 9540s and 540s again.

then i try to power up again with 12V 20A power supply.
i found 1 thing that i never try before.

without audio board,
i test the voltage for GND with pin 1 and pin 2(the 6 pin connector)
i get +42V for pin 1, -42V for pin 6.

with audio board,
when plug-in the 6 pin connector, it stil got some sparking.
i test again the voltage for GND with pin 1 and pin 2(the 6 PIN connector).

i get +40V for pin 1, -39.8V for pin 6.
and also Q619(KCS2690A) and Q620(KCS1220A) for 15V regulator part getting very hot (cannot touch with hand).

is this give u any information?

 

[jasyip5052]

forget to answering u.

i test it again without all the FET.

+40V for Q504 and Q508.
-40V for Q511 and Q515.

 

[Perry Babin]

You need to adjust VR601 so that you have +49v.

Adjust VR602 so that you have -49v.

Are the overheating transistors clamped tightly to the heatsink?

 

[jasyip5052]

i try already. if im using car battery supply it is 49V.

yes, clamp tightly to the heasink already.

i have teat also for the speaker connector (without all FET),
i get 8.6V for Lch, 9.35V for Rch

after that, i remove the 10 pin connector and test the speaker connector again.
i get 8.6V for Lch, 14.4V for Rch.

Can i ask that, for normal amp, how much the speaker output voltage without audio input?

 

[Perry Babin]

I've never removed all of the outputs from a 1507 and measured the voltages as you've done so I can't say whether that's normal or not.

When this amp is in good working order, the DC voltage across the speaker terminals will be very near 0.00v.

What are you using as a power supply that won't allow the amp to produce more than 40v DC of rail voltage?

 

[jasyip5052]

im just using the CPU power supply only.

so, i also get this reading before remove all the FET.

 

[Perry Babin]

so, i also get this reading before remove all the FET.

What readings, you've posted many different ones?

 

[jasyip5052]

for the speaker connector ,
i get 8.6V for Lch, 9.35V for Rch

after that, i remove the 10 pin connector and test the speaker connector again.
i get 8.6V for Lch, 14.4V for Rch.

 

[Perry Babin]

Post the DC voltage on all of the terminals of Q619 and 620.

 

[jasyip5052]

Q619
E - -11v
C - -11.3v
B - -0.04v


Q620
E - +15.4v
C - +30v
B - +16v

 

[Perry Babin]

Do you have 619 and 620 reversed?

Is either 608 or 609 shorted?

 

[jasyip5052]

i hv check the reading without remove the FET.

Q608 & 609
G - 0.1ohm
S - 10ohm and increasing none stop
D - 0 ohm

is it normal??

 

[Perry Babin]

I'm sorry. Q619 and Q620. D608 and D609.

 

[jasyip5052]

when i try to test it, suddenly E632 get blow. so im not try it.

beside that i have test my amp body to GND point. i hv found 7.6V of it.

then i test it with OHM, i get 14ohm of it.

 

[Perry Babin]

If that capacitor failed, any of the following are possible.

the probe shorted between the legs of the transistor
the transistor (Q620) failed-shorted
the diode (ZD609) was out of the circuit or open

 

[jasyip5052]

i found it getting short for Q620. So i need to replace it 1st next week.

beside that i have test my amp body to GND point. i hv found 7.6V of it.

it is still ok??

 

[jasyip5052]

i cannot get the part in this weekend. i will try to install back the Q619 and Q620. D608 and D609. then i will test again to get the reading.

THANKS.

 

[jasyip5052]

any 1 can help me??
im looking for my component to replace for few month already, but still cannot get it.
KCF25A20 and c25p20fr. this component is manufac by NIHON.
I cannot found the product of this company in Malaysia.
can i replace with other type?