speaker protection relay issue

[daz]

Just shotgun the caps like Enzo said. If you're not detecting an offset and the detection IC is good. That's probably the cause. If they are surface mounted caps, it goes double.

This is all above my head, but what do you mean by "shotgun the caps"?

[AtomicMassUnit]

This is all above my head, but what do you mean by "shotgun the caps"?

He means replace them all instead of trying to find the bad one.

[daz]

Oh geez.....when i aw "shotgun the caps like enzo said", i was wondering where he said that....i never saw his post ! Thanks enzo, great post and sorry i missed it the 1st time around ! I have no idea how that happened but i will check what you said and replace the caps if necassary. pretty new amp tho, i wouldn't think that would happen from heat that fast but if thats all that remains i'll do that last.

[g1]

what could make it work fine for a 1/2 hour and then other times the relay goes open 10 seconds after the amp was started and the relay had already gone closed ?

Don't rule out the relay itself, although if this were the case, the coil voltage should be stable while the relay opens. More likely the caps Enzo suggested.

[daz]

The TA 3717, and shouldn;t that be a TA7317?

Hmmmm... i wonder if i have the latest schematic. the version doesn't match now that i looked, which i did because i don't see anything resembling that number at all. Schematic says V1.3 and the board in the amp says V1.5. Can someone point me to a schematic of revision 1.5?

EDIT: I see now...the TA 3717 is a small board, not a packaged circuit. The only one of the caps you (enzo) mentioned thats near it is the .47uf, and i just replaced that. I didn't have a 100v as the cap i replaced was, but the schematic asks for a 50v and thats what i had. Maybe the 100v was added in V1.5, who knows. anyways, i gotta wonder if it's the TA3717 itself.

[daz]

Ahhhh, well, I replaced every electrolytic on the output board and even found the same relay and replaced that. Any thoughts as to what the logical next step to take is? I'm thinking replacement of the protection board, which is just that in this amp instead of a 9 pin package style IC.

[daz]

So the amp is going into protect.
You need to find why.
The TA3717 is a 'protect' IC. (Edit:" TA7317" Correct IC#)
You need to find out if the ic itself is at fault (including the relay circuit) or is it doing what it is designed to do.
Which is: drop out the relay if overcurrent (pin 1) or Vdc present (pin 2 & 3) is an actual fault input.
Monitor those pins & document what is happening, on those pins, when the relay is energized & when it drops out.

Ok, i see 1/2 a volt (.4XX mV) at pin 2 when relay kicks out. Before that it's down at about 100 mV when i start the amp. At around 400+ mV it hovers there maybe slightly moving up when the relay kicks out. What would be the most likely culprit? Or should 1/2 a volt even trigger the protection?

[daz]

I know this is a stupid question, but if i wasn't one of the 3 stooges of electronics i wouldn't be here asking in the 1st place. What i'f i put a large cap like a 22UF in line before pin 2? It's likely a stupid question because if that worked they would likely have one there to block small DCV's. I traced it back on the schematic and the only thing i can figure with my 3stooges mindset is the outputs must be at fault.

[Jazz P Bass]

Ok, i see 1/2 a volt (.4XX mV) at pin 2 when relay kicks out. Before that it's down at about 100 mV when i start the amp. At around 400+ mV it hovers there maybe slightly moving up when the relay kicks out. What would be the most likely culprit? Or should 1/2 a volt even trigger the protection?

The TA7317 datasheet indicates that a 900 mv signal is the minimum trip point.
Pin 2 & pin 3 can cause a Vdc trip.
Pin 3 is a thermal trip.
What does that voltage look like?
It may be a faulty IC, in that it is tripping early.
Link:ta7317p | eBay

[Jazz P Bass]

I know this is a stupid question, but if i wasn't one of the 3 stooges of electronics i wouldn't be here asking in the 1st place. What i'f i put a large cap like a 22UF in line before pin 2? It's likely a stupid question because if that worked they would likely have one there to block small DCV's. I traced it back on the schematic and the only thing i can figure with my 3stooges mindset is the outputs must be at fault.

It may be that the output section is at fault.
Why does the offset voltage try to go higher? (right before it trips)
Adding a capacitor in series to pin 2 would only be advisable for troubleshooting, to see how high the dc offset 'wants' to go.
Of coarse removing R336 (220K) would accomplish the same thing.

[Enzo]

So your schematic is not th same as the one Jazz posted? Post your schematic so we can see it.

The TA7317 should be on the board of the power amp module.

If you have some small module in place of the TA7317, then what IC is on that board?


I didn't mention a 100v cap, I don't think. I did mention a 100uf cap. C316

[daz]

What does that voltage look like?
It may be a faulty IC, in that it is tripping early.

You mean on 3? It was something like 280mV and it never fluctuates. I did think it may be the "IC" actually. Several things seem to point to that and the outputs I think should be ok because at times i can play the hell out of the things for 30 minutes with no problem.

So your schematic is not th same as the one Jazz posted? Post your schematic so we can see it.

mine is different, but i think they are basically the same except his shows a IC while mine is drawn differently with 9 points instead of an IC, then the mini protect board is drawn under then main schematic as a seperate schematic. If you want i can email it, or someone tell me of a site i can upload it because it's a pdf

The TA7317 should be on the board of the power amp module.

If you have some small module in place of the TA7317, then what IC is on that board?

It's a tiny board with micro components, not a packaged IC. And yes, it's on the output board

I didn't mention a 100v cap, I don't think. I did mention a 100uf cap. C316

Not sure what you are referring to, but i replaced all electros on the board.

[Enzo]

Post it here directly. Open the quick reply box. See the litle icons across the top of it? The one on the right end is ABC, for example. Move your cursor over each icon and the browser should tell you what it means. From the right, the fourth one should be INSERT IMAGE. CLick it. A box should open up with tabs at the top for FROM COMPUTER and FROM URL. Click from computer. Now type or paste in the file name, or click browse and find the file that way. Then click upload files.

[Jazz P Bass]

Can you post s picture of the amplifier module.
Here is a pic from a HA7000.
The TA7317 is clearly shown off to the left of the relay.
It is an 8 pin inline ic.
And a pic from a HA3500

[daz]

They look a bit different. Similar, but component locations vary bit. And like i said in place of that IC in the top pic, mine has a 1x1" circuit board with micro components standing up in the middle of the power board attached with 9 soldered pins. I may be able to borrow a camera later and if i can i'll post a pic.

Enzo, it's a pdf. Nice to see this place hosts for you ! thats great, and ui never knew. heres the pdf...
Hartke HA-5500.pdf