what is this?

[scampo77]

i know im new at this so hopefully this will be easy for someone to help with.

i am working on a MTX 3401.

there are 2 independant circut boards one for the amp stuff and a seperate one that houses the gains and adjustments. its the adjustment board im having problems with

it looks like a small silver barrel and has the numbers "10 16s 4f8" on the top of it, i put power to the amp and this part actually exploded and shot across the room. is this normal? what is this thing and where do i get a new one?

what causes this to fail? should i be looking for another problem?

[Perry Babin]

Probably a 10uF 16v SMD capacitor. Mouser will have it. You'll have to measure the one you have to match it up with the replacement.

This happens often when the regulators fail. Did you have the transistors clamped tightly to the heatsink when it blew?

[scampo77]

i cant measure it, all that is left on the PCB is just 2 tabs, it seriously dynamited in a big loud blaze of glory. do you think i can just guess and use the specs you recomended?

yes the transistors were bolted to the heatsink. this little capacitor was on a completely seperate board within the same amp.

what will cause the "regulator" to cause this to happen? should i check that it is ok before putting in a new capacitor?

[Perry Babin]

Before you replace it, you need to measure the DC voltage from the regulators. I don't have any information on this particular amp. Can you post a few photos of the internals?

If there are other caps with the same markings, you can measure them. The most important measurement is the pad size/spacing. The height isn't likely to be a problem.

When the regulator fails, it often sends full rail voltage to the regulated 15v circuit. This will cause the caps to explode. It can also cause extensive damage to other components. The following thread dealt with a regulator failure in an MTX 7801.

MTX TA7801 repair

[scampo77]

how do i check the regulated voltage? here is some photos im not to sure what im taking pictures of yet. im having difficulty getting the pictures small enough to upload

[scampo77]

here is another picture of the blown cap

[Perry Babin]

Regulated voltage can be checked on any of the audio op-amps. There should be one near the RCA jacks.

You can check rail voltage on the open pads in the large circles (places for additional capacitors). Check it on both sides of the heatsink.

[scampo77]

alright i checked the rail voltage by using the circles i have 49v and 50 v, i need to do somemore reading to find out what a op-amp is

[Perry Babin]

This is a different amp but yours should be similar. The black, 8 legged device in the photo is an op-amp. There should be one in your amp near the RCA jacks. The lower left (near the white circle) is pin 1, the lower right is pin 4. The upper left is pin 8. On pin 4 you should have approximately -15v. On pin 8, you should have approximately +15v.

[scampo77]

it is even the same part number as mine. the voltages i measured line up with my picture. i think its safe to say that the regulator has failed. i just put the neg lead on the feed to the amp and then stabbed the leads with the pos lead

-0 -48
-45 0
-45 -45
-46 -46