Help!! My Mcintosh c2500 preamp not working

Audiophilehi

Audiophilehi

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Joined
Apr 5, 2013
Messages
706
Location
Staten Island, New York
Hi, All

I am having a problem with my Mcintosh c2500 preamp. The left and right output level lights are on as well as all the bottom red led lights except for the mute. The display in the center does not light. The unit is frozen. The only way to turn it off is to unplug it. When I plug it in it automatically turns on. I tried resetting as per page 26of manual with no luck.:reallymad::reallymad:


See below.

Reset of Microprocessors
In the unlikely event the controls of the C2500 stop
functioning, the microprocessors can be reset by performing
the following:
1. Press and hold the STANDBY/ON Push-button for
approximately ten seconds and then release.
2. To switch the C2500 back On press the On
STANDBY/ON Push-button.
Note: This can be performed with the C2500 On or in
the Standby Mode.
Resetting the C2500 to default settings
If it becomes desirable to reset all the adjustable settings
(Setup and Trim Settings) to the factory default
values, perform the following steps:
1. Press both the PROCESSOR and OUTPUT 2
Push-buttons until the Front Panel Display indicates
“FACTORY RESET”.then release the two push-buttons. Several seconds
later the Front Panel Display will indicate “FACTORY
RESET, -COMPLETE-” and the C2500 will
switch Off
 
450628968_640.jpg
 
Audiophilehi.......Try unplugging the C2500 for more than just a minute or so, like maybe 15 minutes. Then try pressing and holding the STANDBY/ON push-button while you plug the C2500 back into power and hold it for ten seconds to see if that will reset the microprocessor.

Were your trying to update the firmware when this situation popped up?
 
Double-D said:
Audiophilehi.......Try unplugging the C2500 for more than just a minute or so, like maybe 15 minutes. Then try pressing and holding the STANDBY/ON push-button while you plug the C2500 back into power and hold it for ten seconds to see if that will reset the microprocessor.

Were your trying to update the firmware when this situation popped up?
Click to expand...

HI Dan,

That didn't work. I wasn't attempting any firmware update. It was working fine a few days ago. Really bad timing as I just received the latest Beatles vinyl Mono Box set.
 
Audiophilehi.......Did you experience any outages or surges in utility power? Do you have a surge arrestor installed on your service panel?

I looked at the C2500 schematic and only see a single 800mA time delay fuse, so it isn't some additional internal fuse that has blown. It appears there has been a microprocessor or firmware failure. This is going to require your C2500 to be serviced. I wish I could have been more help.
 
Double-D said:
Audiophilehi.......Did you experience any outages or surges in utility power? Do you have a surge arrestor installed on your service panel?

I looked at the C2500 schematic and only see a single 800mA time delay fuse, so it isn't some additional internal fuse that has blown. It appears there has been a microprocessor or firmware failure. This is going to require your C2500 to be serviced. I wish I could have been more help.
Click to expand...

Thanks Dan, I was afraid of that. I have the unit plugged into a PS Audio Power Plant Premier. I didn't notice any surges and there was no power outage.

Thanks again!
 
All,

Good news!! I contacted Chuck Hinton at McIntosh and followed the below procedure and all is good again.:celebrate008_2:

Thanks Dan for your help and if Chuck checks in Thanks to you as well.

McIntosh is truly the best!!:happy:

a. Disconnect the AC power.
b. Remove the bottom cover – Yes turn the unit over.
c. Locate the main microcontroller. It is the square IC approx. 1cm across on the control PCB.
d. Locate the two buttons adjacent to the microcontroller labeled “PROG” and “RESET”.
e. Press and hold the “PROG” button while also plugging in the AC power cord. This will take some dexterity.
f. Hold the “PROG” button for at least 10 seconds to properly load the default boot loader.
g. After 10 seconds remover the AC power cord and release the button.
h. Re-apply the AC power once again.
i. The unit will be on – sort of… The front panel display will be dark and all the red LEDs will be lit. This is expected. The unit is now in update mode and should accept the firmware update.
j. NOTE: When the update software is run and the unit is discovered, the attached device model will be listed as “unknown”. This is expected. Just answer all prompts in the affirmative.
 
Audiophilehi.......That is fantastic. One more tidbit of useful information to fill away for future use. I am happy for you that McIntosh and Chuck had a solution for the problem that worked.

Happy days are here again. :yahoo1:
 
Double-D said:
Audiophilehi.......That is fantastic. One more tidbit of useful information to fill away for future use. I am happy for you that McIntosh and Chuck had a solution for the problem that worked.

Happy days are here again. :yahoo1:
Click to expand...

Thanks Dan!

Happy day's are most definitely here again! Just in time to listen to my just delivered Beatles vinyl mono box set.

Below is the full document for all who need. It's for the C50 but also applied to the C2500.


Solutions to common C50 Software update problems:

1. Choosing a computer
The right computer unfortunately means everything. The proprietary driver used by the IC manufacturer to communicate with the microcontroller has some difficulties running in Windows 7 on an AMD computer. It seems that any other combination works just fine. The good news is that this is only a temporary problem until the IC manufacturer resolves its issues.
If you attempt to perform the update using a WIN7 OS on an AMD computer, the software will cause the C50 to lockup and not recover without removing the bottom cover!!

2. Unlocking a ‘Bricked’ C50
So if you did not heed the warnings above and the C50 is now unresponsive do the following:

a. Disconnect the AC power.
b. Remove the bottom cover – Yes turn the unit over.
c. Locate the main microcontroller. It is the square IC approx. 1cm across on the control PCB.
d. Locate the two buttons adjacent to the microcontroller labeled “PROG” and “RESET”.
e. Press and hold the “PROG” button while also plugging in the AC power cord. This will take some dexterity.
f. Hold the “PROG” button for at least 10 seconds to properly load the default boot loader.
g. After 10 seconds remover the AC power cord and release the button.
h. Re-apply the AC power once again.
i. The unit will be on – sort of… The front panel display will be dark and all the red LEDs will be lit. This is expected. The unit is now in update mode and should accept the firmware update.
j. NOTE: When the update software is run and the unit is discovered, the attached device model will be listed as “unknown”. This is expected. Just answer all prompts in the affirmative.

3. I loaded the software and connected the C50 but the computer could not find the drivers:
When Windows tries to find the driver and fails it will give the user two options:

a. Find the drivers automatically (which just failed).
b. Allow the user to specify the location of the driver.
Select the second option and browse to the following location (this may vary depending on OS): C:\Program Files (x86)\McIntosh Laboratory\McIntosh C50-V2.00 Firmware Update\driver
Now let Windows load the driver.

4. I loaded the software and connected the C50 but the computer loaded a GPS Camera Driver:
If Windows does not find the update drivers on its own and the computer is internet connected, it will automatically look elsewhere for a driver.
For this application we are using the default CDC driver provided by the microcontroller IC manufacturer. Unfortunately, there is a GPS Camera manufacturer who did the same thing but also registered theirs with Microsoft.
The good news is that it doesn’t matter. It is precisely the same driver under a different name and will work fine with our updater.

5. I loaded the software, put the C50 in update mode, connected the two via USB cable, and discovered and loaded the correct driver but the updater still says “scanning”.

This is actually a rare occurrence but it can happen. By all accounts everything should work but does not. Follow these steps in this order and retry along the way:

a. Exit the updater and disconnect the C50.
b. Restart the computer ( let it fully boot up)
c. Reconnect the C50 (listen for the tone or verify the driver is loaded in device manager)
d. Restart the updater.
e. If this fixes the problem you are done.
f. If the updater is still stuck in “scanning”, go to item #2 above and follow the procedure for unlocking the C50.
 
Got a brand new c2500, and was playing around with settings,
nothing connected, and except for the fact that the front panel on/standby switch would not turn on the unit, but the remote did, everything seemed to work, i.e. Changing settings etc.. Just for fun hooked up my iPhone thru a Dragonfly Red, and headphones, and this worked fine.

Today I was connecting it up For real integration into audio system, first setting and using it as a passthru for my Pioneer Sc-lx701 avr, and connecting the c2500 to my xpa-1 monoblock/B&W cm10s2. I go to the home theater pass through trigger to work turning the unit on. And that turns it on----Now however, nothing works on the front panel or the remote. I can only get the unit to turn on and off using the trigger, i.e. through the passthru rear trigger jack, nothing else ----and I disconnected everything when I first noticed that nothing worked.


i tried the two resets in the manual and as above, but not the turn over, setereset and program as described above, because I am also little unclear what those steps are.

Can anyone clarify that reset mechanism for me? Also I use MacBook IOS, not window although if pushed I must have some old cpus with windows, maybe, somewhere....help if possible?

thanks
 
Welcome to the forum forum NorthernEscape, thank you for joining.
 
Welcome to AS!

Do you have the latest Firmware update? You can download from McIntosh website. Must be on Windows PC. then see post #10 in this thread. That's what worked for me when my c2500 was hosed up. Good Luck!
 
Welll........

Thank you so much for responding. I called Chuck Hinton, at Macintosh and lo and behold, he told me to go ahead, basically as described above. He forwarded to me new software driver set for the C 2500 and I dug up an old Windows laptop. Took off the bottom, found and hit the reset button, and managed to load the new software. Hit the reset button and things began to light up ;).




However, I had tried the on/standby button when I first got the unit, and nothing happened. The button felt sticky and "funny", and was definitely different from the other front panel buttons. With the bottom panel still removed, I tried that button and noticed that the circuit board to which the button functions, had an obvious deviation away from the front panel, and hence "locked out" because of this increased extension. The board is not really well supported or tethered at this end. Chuck says he has seen this in about 10 or so c2500 preamps. To fix I would need to take in for repair, but there is really no good dealer here( I moved the amp from where I bought it, so the original dealer can't really help. Since the remote works fine, and I wanted to get up and going finally with this new pre, I buttoned it up and will use only the rrremote, and not take a chance on the button locking, which it would if used. So kind of a design fault by Mac, that should be corrected, and I wonder if they changed that in the c2600? Anybody know?


Thanks....
 
NorthernEscape said:
Welll........

Thank you so much for responding. I called Chuck Hinton, at Macintosh and lo and behold, he told me to go ahead, basically as described above. He forwarded to me new software driver set for the C 2500 and I dug up an old Windows laptop. Took off the bottom, found and hit the reset button, and managed to load the new software. Hit the reset button and things began to light up ;).




However, I had tried the on/standby button when I first got the unit, and nothing happened. The button felt sticky and "funny", and was definitely different from the other front panel buttons. With the bottom panel still removed, I tried that button and noticed that the circuit board to which the button functions, had an obvious deviation away from the front panel, and hence "locked out" because of this increased extension. The board is not really well supported or tethered at this end. Chuck says he has seen this in about 10 or so c2500 preamps. To fix I would need to take in for repair, but there is really no good dealer here( I moved the amp from where I bought it, so the original dealer can't really help. Since the remote works fine, and I wanted to get up and going finally with this new pre, I buttoned it up and will use only the rrremote, and not take a chance on the button locking, which it would if used. So kind of a design fault by Mac, that should be corrected, and I wonder if they changed that in the c2600? Anybody know?


Thanks....
Click to expand...

I have the same issue with my on/standby button as well. I've using the remote as well. Guess I'll get around to getting it repaired. Hate to be without it.

Funny thing it works to reset the microprocessors when the Dac freezes. Go figure!
 
Mine just developed the problem. Both Mc and AC sent me the firmware but it was a no go. Even though I made both places aware that I knew about the removal of the bottom and the prog button to reset, neither
gave me that option. I sent to AC this morning which promises a quick turnaround. The 160$ shipping is ouch though.
 
Audiophilehi said:
I can’t say for sure but since I preformed the procedure and did the firmware upgrade my c2500 has worked flawlessly without any incident.
Click to expand...

Came home tonight and same issue.
It seems like I get exactly 10 months use and then same lock up occurs.
 
Hi Paul, same thing just happened to my C2500. I did as you instructed but still locked up. Blue meters are lit, all red lights are on except mute. I did the reset - pressed PROG button, etc. How long did you have to wait before the unit came back on? Thanks
 
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