Triaxis problem

[Micke F]

Hello!
I've got a Triaxis with the following problem:
All the control leds on the front are black, exept for "dynamic voice" that shows 0.0.
The 8 channeldiodes are lit, the 4 switchdiodes are black.
It doesn't respond to any button or combination of buttons.
And, of course, no sound.

With help from the swedish distributor i got some suggestions from Mesa, and this has been done so far with no luck:
The ribbon cables and connections are checked.
The CPU (IC8), Dart (IC5), 27256 (IC9), 6264-10L (IC10), 3 x 74HC245 (IC4,15 16) and backup battery are replaced.
The supply voltages seems to be ok.

Very greatful to any ideas..
Regards
Mikael

 

[18&Life]

My friend obviously it is broke.
No ideas,just send to mesa to fix it or somebody next to you wich do this job. :wink:
I'm really scared right now.If mine breaks,there's nobody hear to fix it.
:shock:

 

[guitarmaster]

:!:

 

[Micke F]

It seems that your triaxis has a display problem regarding : "mode switching" : all the ryth. and lead modes come from 74HC564 - IC14 on P.C.B TX3A. Another component that could have caused your problem might be : IC3 "display refresh timer" and IC6 "system reset" . I have understood you have replaced CPU/memory components without any improvement, it's for this reason I think the issue could be located in "mode Switching" and "system reset". The trouble could be also easier to solve : a simple cold solder joint in which the solder does not make good contact with the component lead or printed circuit board. Cold joints make a really bad electrical connection and can prevent your circuit from working. These cold joints could be located in "mode switching" ...............maybe. Sorry , I would like to help you in a better way, but unfortunately I'm not an authorized Mesa/Boogie technician.

Thanks a lot for your advise guitarmaster.
I'll look into those things in a few days, (as soon as I get the parts).
I'll let you know what happens.
/Mikael

 

[guitarmaster]

:!:

 

[Micke F]

Hello!
Here is the whole deal.
It's not my amp, i'm a diy:er who try to help people with problems in their amps. I know my way around ordinary tubeamps quite well, but this unit is something else.....beside a tubeamp of course.
And it's an older-than-warranty-unit.
Do you know what! According to the owner of the amp, the midiswitching has been unfunktional for years.
So if a malfunktion in that circuit can block the whole amp there is a good chance that the problem lies there.
I'll check that area and substitute a couple of ic:s there, to see what happens, It will take a day or too, (more parts).
By the way, replacing ic 14, 3 and 6 made no difference.
Among other things, Mesas suggestion about replacing the programmed eprom costed about 100 USD, an unprogrammed unit is about 8 USD.
Watch out.

/Mikael

 

[guitarmaster]

:!:

 

[LUCRETIA]

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