Eclipse 3241 amplifier blowing fuses

jz23 · 17th February 2010, 02:03 AM

Eclipse 3241 pc1121 rev-05

History: Over 10 years ago the amp was sent in to eclipse to have fix and was fixed and working. After a couple of years of use, the amp started playing at a very low volumes even when turned up. Ever since the amp was put in storage.

Now I have interest in fixing the amp and pulled it out to experiment. Powering the amp up I have a 10amp fuse inline with the b+ along with the two 30amp factory fuses. With just the Ground and B+ connected, nothing happens. Once when power is fed to the remote, the amp power light comes on for a second and the fuse blows.

I have the basic tools and was wondering what should be the first then i test or pull out?

Amp info : uses SL162a & FEP16BT rectifiers, P50n06 fets, TL494CN , and TIP35C & TIP36C transitors.

Any help would be great.. Also, I dont want to get this fix else where.

brandes.cm · 17th February 2010, 02:59 AM

If you have a DMM start ohming out the fets pin 1 to 2, 1 to 3, 2 to 3 and verify if anything is shorted. If your meter has diode mode use it rather than ohms scale.
That is where I would start.

Perry Babin · 17th February 2010, 03:03 AM

The TIP35/36 are the most likely suspects.

jz23 · 17th February 2010, 03:18 AM

Quote:

Originally Posted by brandes.cm

If you have a DMM start ohming out the fets pin 1 to 2, 1 to 3, 2 to 3 and verify if anything is shorted. If your meter has diode mode use it rather than ohms scale.
That is where I would start.

Checked all those legs and found no continuity. (did not remove fets from board during test)
Also checked all the surface mount resistors inline with the gate of the fets and and they are all around 47ohms. (didnt remove them from the board which may matter.)

Quote:

Originally Posted by Perry Babin

The TIP35/36 are the most likely suspects.

Let me go research and examine these.

jz23 · 17th February 2010, 04:23 AM

With TIP35/36 transistors still in board, I did some diode tests. For the TIP35(npn) I touched the red lead to pin 1(base) and touched the black lead to pin 2 and took a recording and another recording with the black lead touching pin 3. I did the same for the TIP36 but just reversed the leads.

All reading except for one pair had readings from 0.467v-0.494v. The last pair had readings of TIP35: 0.001v, 0.024v & TIP36: 0.457v, 0.024v.

Do these readings smell correct or do I have to pull the transistors to get a more accurate reading?

brandes.cm · 17th February 2010, 12:27 PM

The last pair is defective, shorted. Replace those, but order enough to do the repair again. Order twice as many as you think you need!!

jz23 · 17th February 2010, 04:03 PM

Is it good practice to replace all of the output transistors or does it even matter in this situation? What would cause this and what should I check/replace to prevent this from happening again? I rather know what to replace so I can make one purchase order.

Perry Babin · 17th February 2010, 04:24 PM

There's probably no reason to replace the outputs in the other channels but if it's worth the extra $10-12 for the price of the parts...

When ordering the TIP 36/36, make sure you order the correct case style. Some have a metal tab. Others have the entire front encased in plastic. Sometimes, the clamping system for one won't work with the other.

You should check the driver transistors and the base resistors that were driving the failed outputs.

To confirm that you have found all of the defective parts, you could move the outputs from another channel to the blown channel to see if it produces clean audio.

Before applying power, clamp ALL semiconductors to the heatsink. The 10 amp fuse will help protect the amp but it won't prevent further damage if the semiconductors aren't clamped down. Without being clamped, the power transistors can fail in just a few seconds.

russiannuke · 23rd March 2010, 02:20 AM

Hello everyone,
I am having the same problem with the amp blowing fuses on the same amplifier model. The only difference is that my amp is REV-04. I have tested the all the TIP35C&TIP36C and come up with readings ranging from .581v-.612v for B->C and .592v-.621 for B->E. (red pin to B for TIP35 and black pin to B for TIP36). I have also verfied that there are no shorts in between the pins of the fets. This amp was sent into eclipse to be serviced and eclipse soldered resistors onto the back of the board with values of 220 ohms to each channel. They did a pretty bad job, but they still seem to be in working order. There are no obvious scorch marks or blown caps, but it blows fuses immediately after powering on the head unit. Any help or advice would be greatly appreciated. Thanks in advance.

Perry Babin · 23rd March 2010, 05:29 AM

If you remove the rectifiers (probably has 4 of them), does it stop blowing fuses?

Use a relatively small fuse in series with the B+ line and have all transistors clamped when you power it up.

17th February 2010, 02:03 AM	#1
jz23 diyAudio Member Join Date: Apr 2007	Eclipse 3241 amplifier blowing fuses Eclipse 3241 pc1121 rev-05 History: Over 10 years ago the amp was sent in to eclipse to have fix and was fixed and working. After a couple of years of use, the amp started playing at a very low volumes even when turned up. Ever since the amp was put in storage. Now I have interest in fixing the amp and pulled it out to experiment. Powering the amp up I have a 10amp fuse inline with the b+ along with the two 30amp factory fuses. With just the Ground and B+ connected, nothing happens. Once when power is fed to the remote, the amp power light comes on for a second and the fuse blows. I have the basic tools and was wondering what should be the first then i test or pull out? Amp info : uses SL162a & FEP16BT rectifiers, P50n06 fets, TL494CN , and TIP35C & TIP36C transitors. Any help would be great.. Also, I dont want to get this fix else where.

17th February 2010, 03:03 AM	#3
Perry Babin diyAudio Member Join Date: Nov 2003 Location: Louisiana	The TIP35/36 are the most likely suspects. __________________ Links >> Basic Car Audio Amp Repair --- Basic Car Audio Electronics --- Basic Transistor Testing --- Basic Switching Power Supply Design --- Basic Computer Skills << Links

17th February 2010, 04:24 PM	#8
Perry Babin diyAudio Member Join Date: Nov 2003 Location: Louisiana	There's probably no reason to replace the outputs in the other channels but if it's worth the extra $10-12 for the price of the parts... When ordering the TIP 36/36, make sure you order the correct case style. Some have a metal tab. Others have the entire front encased in plastic. Sometimes, the clamping system for one won't work with the other. You should check the driver transistors and the base resistors that were driving the failed outputs. To confirm that you have found all of the defective parts, you could move the outputs from another channel to the blown channel to see if it produces clean audio. Before applying power, clamp ALL semiconductors to the heatsink. The 10 amp fuse will help protect the amp but it won't prevent further damage if the semiconductors aren't clamped down. Without being clamped, the power transistors can fail in just a few seconds. __________________ Links >> Basic Car Audio Amp Repair --- Basic Car Audio Electronics --- Basic Transistor Testing --- Basic Switching Power Supply Design --- Basic Computer Skills << Links

23rd March 2010, 05:29 AM	#10
Perry Babin diyAudio Member Join Date: Nov 2003 Location: Louisiana	If you remove the rectifiers (probably has 4 of them), does it stop blowing fuses? Use a relatively small fuse in series with the B+ line and have all transistors clamped when you power it up. __________________ Links >> Basic Car Audio Amp Repair --- Basic Car Audio Electronics --- Basic Transistor Testing --- Basic Switching Power Supply Design --- Basic Computer Skills << Links

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17th February 2010, 02:59 AM	#2
brandes.cm diyAudio Member Join Date: Sep 2009 Location: Wisconsin	If you have a DMM start ohming out the fets pin 1 to 2, 1 to 3, 2 to 3 and verify if anything is shorted. If your meter has diode mode use it rather than ohms scale. That is where I would start.

17th February 2010, 04:23 AM	#5
jz23 diyAudio Member Join Date: Apr 2007	With TIP35/36 transistors still in board, I did some diode tests. For the TIP35(npn) I touched the red lead to pin 1(base) and touched the black lead to pin 2 and took a recording and another recording with the black lead touching pin 3. I did the same for the TIP36 but just reversed the leads. All reading except for one pair had readings from 0.467v-0.494v. The last pair had readings of TIP35: 0.001v, 0.024v & TIP36: 0.457v, 0.024v. Do these readings smell correct or do I have to pull the transistors to get a more accurate reading?

17th February 2010, 12:27 PM	#6
brandes.cm diyAudio Member Join Date: Sep 2009 Location: Wisconsin	The last pair is defective, shorted. Replace those, but order enough to do the repair again. Order twice as many as you think you need!!

17th February 2010, 04:03 PM	#7
jz23 diyAudio Member Join Date: Apr 2007	Is it good practice to replace all of the output transistors or does it even matter in this situation? What would cause this and what should I check/replace to prevent this from happening again? I rather know what to replace so I can make one purchase order.

23rd March 2010, 02:20 AM	#9
russiannuke diyAudio Member Join Date: Mar 2010 Location: Pico Rivera, CA	Hello everyone, I am having the same problem with the amp blowing fuses on the same amplifier model. The only difference is that my amp is REV-04. I have tested the all the TIP35C&TIP36C and come up with readings ranging from .581v-.612v for B->C and .592v-.621 for B->E. (red pin to B for TIP35 and black pin to B for TIP36). I have also verfied that there are no shorts in between the pins of the fets. This amp was sent into eclipse to be serviced and eclipse soldered resistors onto the back of the board with values of 220 ohms to each channel. They did a pretty bad job, but they still seem to be in working order. There are no obvious scorch marks or blown caps, but it blows fuses immediately after powering on the head unit. Any help or advice would be greatly appreciated. Thanks in advance.

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