Alpine mrv-f300 works fine for 10 min and then audio gets bad

ivkata · 11th December 2010, 11:04 PM

I got this amp here Alpine mrv-f300 its a 4 chanell v12 amp.will work fine for 10 min all audio chanels sound great and then distortion and gets worse ans worse.All chanels go bad at the same time ,any info is apresiated

Perry Babin · 12th December 2010, 12:35 AM

What do you mean when you state that 'all channels go bad'? Do the outputs in them fail and have to be replaced?

I'm assuming that you have the transistors clamped to the heatsink.

ivkata · 12th December 2010, 01:24 AM

well the amp will work fine for 10 min and will start distortions in all chanels.none of the output tested bad.if i let the amp stay overnight will work aggain for 10 min and the same.all transistor are clamped to the heatsink and none gets hot

1moreamp · 12th December 2010, 01:34 AM

Power supply issues maybe ???? at least that's what it sounds like with all 4 channels being effected evenly their only common thing is the power supply. perhaps its going into fault and not shutting down and or muting the channels, this would explain the unique symptoms.... Perhaps bad solder joints, thermally intermittent devices in the lower 16 volt regulators. Just sounding some ideas...

ivkata · 12th December 2010, 02:29 AM

just had it running for 10-11 min the same story.there is a pair of transistors near the power supply a1220a and c2690a that get kinna hot and i doubt they should couse are not mounted on any radiators,i can smell them hot

Perry Babin · 12th December 2010, 02:32 AM

On the upc494 (or whatever 16 pin IC they're using to drive the power supply, measure the DC voltage on all of the pins before and after it shuts down. Which pins have different voltage after it shuts down?

ivkata · 14th December 2010, 04:32 AM

i cant really do that now the amp have desided to play only bad.bad bad bad gate voltage is 0.8 no wonder why shitty audio comes out

kia 494 shows this

Pin 1: 1
Pin 2: 1
Pin 3: 3.8
Pin 4: 0
Pin 5: 1.7
Pin 6: 4
Pin 7: 0
Pin 8: 15
Pin 9: 0.8
Pin 10: 0.8
Pin 11: 15
Pin 12: 15
Pin 13: 5
Pin 14: 5.6
Pin 15: 5.3
Pin 16: 0.00

Perry Babin · 14th December 2010, 09:03 AM

Was the amp producing clean audio when you measured the DC voltage?

ivkata · 14th December 2010, 05:51 PM

nope all bad audio now and when i tested the kia494

Perry Babin · 14th December 2010, 06:41 PM

When the audio is distorted, does the amp have both positive and negative rail voltage on the output transistors?

Does it have both positive and negative regulated voltage on the power supply pins of the op-amps?

11th December 2010, 11:04 PM	#1
ivkata diyAudio Member Join Date: Dec 2010	Alpine mrv-f300 works fine for 10 min and then audio gets bad I got this amp here Alpine mrv-f300 its a 4 chanell v12 amp.will work fine for 10 min all audio chanels sound great and then distortion and gets worse ans worse.All chanels go bad at the same time ,any info is apresiated

12th December 2010, 12:35 AM	#2
Perry Babin diyAudio Member Join Date: Nov 2003 Location: Louisiana	What do you mean when you state that 'all channels go bad'? Do the outputs in them fail and have to be replaced? I'm assuming that you have the transistors clamped to the heatsink. __________________ Links >> Basic Car Audio Amp Repair --- Basic Car Audio Electronics --- Basic Transistor Testing --- Basic Switching Power Supply Design --- Basic Computer Skills << Links

12th December 2010, 02:32 AM	#6
Perry Babin diyAudio Member Join Date: Nov 2003 Location: Louisiana	On the upc494 (or whatever 16 pin IC they're using to drive the power supply, measure the DC voltage on all of the pins before and after it shuts down. Which pins have different voltage after it shuts down? __________________ Links >> Basic Car Audio Amp Repair --- Basic Car Audio Electronics --- Basic Transistor Testing --- Basic Switching Power Supply Design --- Basic Computer Skills << Links

14th December 2010, 09:03 AM	#8
Perry Babin diyAudio Member Join Date: Nov 2003 Location: Louisiana	Was the amp producing clean audio when you measured the DC voltage? __________________ Links >> Basic Car Audio Amp Repair --- Basic Car Audio Electronics --- Basic Transistor Testing --- Basic Switching Power Supply Design --- Basic Computer Skills << Links

14th December 2010, 06:41 PM	#10
Perry Babin diyAudio Member Join Date: Nov 2003 Location: Louisiana	When the audio is distorted, does the amp have both positive and negative rail voltage on the output transistors? Does it have both positive and negative regulated voltage on the power supply pins of the op-amps? __________________ Links >> Basic Car Audio Amp Repair --- Basic Car Audio Electronics --- Basic Transistor Testing --- Basic Switching Power Supply Design --- Basic Computer Skills << Links


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

12th December 2010, 01:24 AM	#3
ivkata diyAudio Member Join Date: Dec 2010	well the amp will work fine for 10 min and will start distortions in all chanels.none of the output tested bad.if i let the amp stay overnight will work aggain for 10 min and the same.all transistor are clamped to the heatsink and none gets hot

12th December 2010, 01:34 AM	#4
1moreamp diyAudio Member Join Date: Dec 2005 Location: Northern California	Power supply issues maybe ???? at least that's what it sounds like with all 4 channels being effected evenly their only common thing is the power supply. perhaps its going into fault and not shutting down and or muting the channels, this would explain the unique symptoms.... Perhaps bad solder joints, thermally intermittent devices in the lower 16 volt regulators. Just sounding some ideas...

12th December 2010, 02:29 AM	#5
ivkata diyAudio Member Join Date: Dec 2010	just had it running for 10-11 min the same story.there is a pair of transistors near the power supply a1220a and c2690a that get kinna hot and i doubt they should couse are not mounted on any radiators,i can smell them hot

14th December 2010, 04:32 AM	#7
ivkata diyAudio Member Join Date: Dec 2010	i cant really do that now the amp have desided to play only bad.bad bad bad gate voltage is 0.8 no wonder why shitty audio comes out kia 494 shows this Pin 1: 1 Pin 2: 1 Pin 3: 3.8 Pin 4: 0 Pin 5: 1.7 Pin 6: 4 Pin 7: 0 Pin 8: 15 Pin 9: 0.8 Pin 10: 0.8 Pin 11: 15 Pin 12: 15 Pin 13: 5 Pin 14: 5.6 Pin 15: 5.3 Pin 16: 0.00

14th December 2010, 05:51 PM	#9
ivkata diyAudio Member Join Date: Dec 2010	nope all bad audio now and when i tested the kia494

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Alpine MRV-F300 Blowing fuses	2ellas	Car Audio	3	15th November 2010 04:03 PM
Alpine MRP-F300 amp is dead, need help with repair	gexamb	Car Audio	37	24th October 2010 03:52 AM
Alpine mrv-f300 remote ciruit	jol50	Car Audio	5	17th May 2010 06:33 AM
Alpine MRV-F401 or MRV-F400 Service Manual	M.André	Car Audio	6	21st February 2010 09:37 PM
Transistor replacement for Alpine F300	spooney	Car Audio	7	14th January 2007 12:10 AM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read