Thanks for your frankness Mooly.
I am not certain what exactly wrong with the card, but my assumption is that it is the same failure as before.
I am not certain what exactly wrong with the card, but my assumption is that it is the same failure as before.
Also, c2, I did try to email the person referenced in your post but the email bounced. If I recall correctly, I don't think I got a reply the last time either.
Just having another look at your pictures...
On the repaired board do the resistors that were replaced go to pins 4 and 7 of the opamp. If so these would be a supply to the device, probably with zeners to regulate it.
As you appreciate it's virtually impossible to diagnose without at least a circuit diagram.
If the repaired board really has had just these components replaced (and the opamp) then it sounds like a "stock" fault as low powered circuitry should be essentially 100% reliable. You should be able to identify any soldering that has taken place on the repaired board.
Are you 100% sure that non of the "power" devices have failed... meaning the any of the devices on the heatsink.
On the repaired board do the resistors that were replaced go to pins 4 and 7 of the opamp. If so these would be a supply to the device, probably with zeners to regulate it.
As you appreciate it's virtually impossible to diagnose without at least a circuit diagram.
If the repaired board really has had just these components replaced (and the opamp) then it sounds like a "stock" fault as low powered circuitry should be essentially 100% reliable. You should be able to identify any soldering that has taken place on the repaired board.
Are you 100% sure that non of the "power" devices have failed... meaning the any of the devices on the heatsink.
Mooly,
Thanks for the response. One major problem I have is that I cannot seperate the board from the heat sink. I have removed all the screws, almost 30 of them, and the board appears to be bonded to the heat sink. So I cannot tell what the back side of the circuti board shows.
I hate to admit defeat. But at the risk of really screwing up the board, I may have to find someone via Harman to fix the board.
Thanks for the response. One major problem I have is that I cannot seperate the board from the heat sink. I have removed all the screws, almost 30 of them, and the board appears to be bonded to the heat sink. So I cannot tell what the back side of the circuti board shows.
I hate to admit defeat. But at the risk of really screwing up the board, I may have to find someone via Harman to fix the board.
Is it just the transistors "appearing" to be stuck. Sometimes heatsink compound can act almost like glue... not sure if that's what you mean. If so you would have to gently prise each one to break the bond.
Hi, please be gentle with me also as I resurrect this thread from the dead with my first post.
I am with zero knowledge and just acquired a proceed HPA3.
I had to use the voltage jumpers to convert it to 220V, and I know there is one channel that outputs DC (so I been told from the one who sold it to me).
Correcting the voltage and disconnecting the broken channel made the amp power up.
However, there is some humming sound from the transformers in the front and upon connecting a speaker to one of the working channels terminals I hear static sound – also some sort of hum.
Considering that I will try to deal with the broken channel later, any suggestion regarding the hum?
Thanks in advance
I am with zero knowledge and just acquired a proceed HPA3.
I had to use the voltage jumpers to convert it to 220V, and I know there is one channel that outputs DC (so I been told from the one who sold it to me).
Correcting the voltage and disconnecting the broken channel made the amp power up.
However, there is some humming sound from the transformers in the front and upon connecting a speaker to one of the working channels terminals I hear static sound – also some sort of hum.
Considering that I will try to deal with the broken channel later, any suggestion regarding the hum?
Thanks in advance
I recently picked up one of these 5 channel amps too.
I think mine is 100% working but I want to mod and upgrade it to keep it that way.
Thanks.
Srinath.
I think mine is 100% working but I want to mod and upgrade it to keep it that way.
Thanks.
Srinath.
Hi,
"If it ain't broke, don't try to fix it" is the best way to keep something working.
rgds, sreten.
"If it ain't broke, don't try to fix it" is the best way to keep something working.
rgds, sreten.
Not if it will die spectacularly and take out 1/2 the innards when it does.
I am unable to find much on google on the amp.
Thanks.
Srinath
I am unable to find much on google on the amp.
Thanks.
Srinath
Can someone tell me if this amp can be modded to prevent this type of failure, or if its a repair strictly.
I am going to get the avp/5 into use in a bit. Hope to know and keep it from blowing.
Thanks.
Srinath.
I am going to get the avp/5 into use in a bit. Hope to know and keep it from blowing.
Thanks.
Srinath.
I have a Proceed AMP5, also experiencing this problem. Here is a temporary fix / workaround for this problem:
(Assuming you have ruled out overheating and speaker problems, which are legitimate reasons for the amp to go into to protection mode. Rule these issues out by disconnecting all speakers and inputs (including the DC trigger if you are using it), and leaving the amp unplugged in a cool area for an hour, then switch power on with everything but the power unplugged from the back. If the protection circuitry still engages you have a problem inside the amp.)
As always, turn off the power switch on the front, wait until the lights go out, unplug the power from the back of the unit, and wait 15 minutes prior to opening the case (it will probably take you that long anyway to find a hoist and move this behemoth to a work area anyway.) Technically you should bleed the capacitors down because they can hold enough of a charge to shock or even kill you! How was mentioned elsewhere in this thread. Ok safety warning aside:
This happens when detection circuitry somewhere in the amp detects that something is not right. On the edge of each channel is a connector that feeds back to the mainboard and allows it to monitor each channel for issues, among other things.
Here is a picture of the connectors:
Unplug one connector at a time, and being careful not to touch internals, power on the unit and you can determine which channel is having the issue.
Afterwards, you can repair or replace that channel, or if you leave it disconnected you can use the amp in reduced capacity (5 channel amp becomes a four channel, etc). Ideally you should remove the channel that is not in use entirely so it has no connection to the power supply.
Good luck.
(Assuming you have ruled out overheating and speaker problems, which are legitimate reasons for the amp to go into to protection mode. Rule these issues out by disconnecting all speakers and inputs (including the DC trigger if you are using it), and leaving the amp unplugged in a cool area for an hour, then switch power on with everything but the power unplugged from the back. If the protection circuitry still engages you have a problem inside the amp.)
As always, turn off the power switch on the front, wait until the lights go out, unplug the power from the back of the unit, and wait 15 minutes prior to opening the case (it will probably take you that long anyway to find a hoist and move this behemoth to a work area anyway.) Technically you should bleed the capacitors down because they can hold enough of a charge to shock or even kill you! How was mentioned elsewhere in this thread. Ok safety warning aside:
This happens when detection circuitry somewhere in the amp detects that something is not right. On the edge of each channel is a connector that feeds back to the mainboard and allows it to monitor each channel for issues, among other things.
Here is a picture of the connectors:
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Unplug one connector at a time, and being careful not to touch internals, power on the unit and you can determine which channel is having the issue.
Afterwards, you can repair or replace that channel, or if you leave it disconnected you can use the amp in reduced capacity (5 channel amp becomes a four channel, etc). Ideally you should remove the channel that is not in use entirely so it has no connection to the power supply.
Good luck.
That is fantastic, I will keep this idea in mind.
I am hoping to fix my working amp 5 to the point it wont die.
It really really sounds great pushing those Carver III amazings off a nad 1155 preamp. That combination was very synergistic.
Thanks.
Srinath.
I am hoping to fix my working amp 5 to the point it wont die.
It really really sounds great pushing those Carver III amazings off a nad 1155 preamp. That combination was very synergistic.
Thanks.
Srinath.
Has anyone managed to get a schematic for this series of amplifier from Proceed? I think it's very poor service for Harmon to brush you off like that. Shame on them. Not troubleshooting might be fair enough.. but to not provide a schematic is just lacking common decency, leaving their customers - who are also potentially their best salespeople, out in the cold!
I contacted Harman and was told they will not provide any service information or schematics for any product no matter how old it is
even i contacted Harman they are not interested in providing the schematics, this is insane. i will not buy products of Harman
Please be realistic, they do not supply schematics to*end users* .
Remember the "no user serviceable parts inside" sticker.
They DO send schematics and spare parts to Authorized Service Centers.
They will gladly provide a list of such AWSC shops.
Remember the "no user serviceable parts inside" sticker.
They DO send schematics and spare parts to Authorized Service Centers.
They will gladly provide a list of such AWSC shops.
Three years later and I forgot I figured out this workaround! But alas the Proceed AMP5 has failed 2 more channels, and then had this error again, so my amp has been removed from the rack. When I have time I am going to try to repair it... will post any positive results here...