General Forum

Re: penta 3 display

baileyr — Wed, 18 Jan 2012 14:53:16 GMT

Now this is bloody wierd

the first thing i swoped with the good speaker were the displays and they both definatly worked with the good speaker.

I swoped the base's over and only the good speakers base powerd BOTH displays. So after some rewiring and continuity checks i put everything back together but still no display in the 1 speaker.

ive now swoped the displays again and the display out of the good speaker now works on the faulty one but not the other way round.

By swoping the pcb's ive now got it down to the rear circuit board from the display (must have damaged something with all the taking apart)

Re: penta 3 display

tournedos — Wed, 18 Jan 2012 14:27:34 GMT

OK, so the display apparently works and has power... I believe it's time to try and find where the data gets lost then.

This is unfortunately a bit more involved (and difficult without the service manual) as there are some active electronics in between. What you might do is check the solderings of the Powerlink socket in the bottom of the amp - I presume you're using that since you have an Ouverture.

Re: penta 3 display

baileyr — Wed, 18 Jan 2012 13:19:45 GMT

right ive had it apart again, checked all coninuity from the 6pin display plug to the base and all wiring is good. Ive got 12v at pins 2 & 3 and traced them back to the transformer to confirm, still nothing...

Re: penta 3 display

tournedos — Wed, 18 Jan 2012 10:47:57 GMT

baileyr:
on the good speaker im getting 6v (i think) between brown and blue(??) at the plug that conects to the rear circuit board for the display but on the faulty one im getting 0.1v, so next guess would be a resistor maybe?

I have no idea of the colours of the wiring, but the DIN connectors are numbered as they always are (possibly molded in plastic beside the pins as well). The supply to the display modules comes up in pins 2 & 3 (there was an error in my above post). And it's AC, not DC.

And there are actually two separate mains transformers, the smaller one supplies the standby circuit (which is working for you) and the display from another winding. If you have isolated the fault in one of the amplifier modules, it really can't be much else than the wiring / connectors to the display, or a faulty standby transformer.

Re: penta 3 display

baileyr — Wed, 18 Jan 2012 10:31:15 GMT

that was looking promising as the cables had been squashed abit so i rewired the damaged parts.

The problem is definatly somewhere in the base as i swoped it over with the good one. Ive put a link in to make doubley sure its not the fuses, swopped the front circuit board (with the swithes) still nothing. Checked the audio/video switch has continuity and works.

on the good speaker im getting 6v (i think) between brown and blue(??) at the plug that conects to the rear circuit board for the display but on the faulty one im getting 0.1v, so next guess would be a resistor maybe?

Re: penta 3 display

Step1 — Wed, 18 Jan 2012 09:55:07 GMT

plug between base / tower?

Re: penta 3 display

baileyr — Wed, 18 Jan 2012 05:19:09 GMT

if i ignor the display not working everything works exactly as it should. the display (2 x cicuit boards) are good as i swaped them with the good speaker and it works as it should.

I sort of ruled out the cable as i used a brand new one after the fault happend, but then even new ones can be faulty, so i will swop with the known good one.

But if this doesnt work i'm gonna just strip them both down and start swopping parts.

I'll post an update if and when i find the problem part.

thanks to all for the info/help

Re: penta 3 display

tournedos — Wed, 18 Jan 2012 03:56:30 GMT

In Pentas, the displays work completely independently from the amplifier part (they share the same mains transformer, but really nothing else). The displays are also powered on (technically, not visibly) all the time while the speaker is plugged into mains. There's a separate 40 mA mains fuse, but that circuit also powers the standby part of the amp - if the speaker itself turns on and works, there's nothing wrong with that.

Now either

the display doesn't receive power - the fault can be in a transformer winding (unlikely) or in the wiring & connectors between the amp & display. You should have 10 VAC coming up between pins 2 & 3.
the display doesn't receive data (which could also cause it to not turn off, when it doesn't see the STANDBY command) - same wiring problem as above, or a problem in your speaker cables, or in the audio/video mode switch in the speaker
the display itself is faulty - you don't replace it, you get it repaired (they don't make these any more you know...)
Penta 3 seems to have another fuse on the display module itself (can't see why it would give up & blow, though).

I'm quite sceptical of something getting loose or shorted inside the speaker just by chance if you don't even move them around. One likely problem is a short / open in the Powerlink cabling, disabling the data connection. Pinched by a chair leg recently perhaps?

The display module has a couple of capacitors which I hear are sometimes bad. More likely in an old pair than a 3.

Re: penta 3 display

Bentleyman — Tue, 17 Jan 2012 17:57:02 GMT

Rob,

Is everything else with the speaker working normally? E.g. is the sound normal coming from the speaker? Is the speaker going to standby as it should? Is the red/green indicator light working correctly?

Perhaps there could be a slight loose connection with the display itself if everything else works as normal. Could try taking the cover off and just having a play about...

I've never heard of a display actually breaking down but I guess they could do, in which case a replacement display would be in order...

I'm not technical enough to know myself, but hopefully some on here does.

Regards,

Re: penta 3 display

baileyr — Tue, 17 Jan 2012 16:09:00 GMT

i've left the speakers unplugged for a couple of hours, unplugged the ouverture for 10 mins, plugged back int overture then both speakers and still no display on one speaker.

Re: penta 3 display

bsantini — Tue, 17 Jan 2012 15:55:48 GMT

Unplug everything from the mains for "a minute or so." Then, plug in the Overture first, then the speakers. Should be ok.

Re: penta 3 display

baileyr — Tue, 17 Jan 2012 15:11:56 GMT

i my case it just never came back on. Any one else thinking sticky relay??

Re: penta 3 display

bayerische — Tue, 17 Jan 2012 15:09:25 GMT

Bentleyman:

Ok, I thought that's what you meant.

So, what happens with the display when the unit is turned back on again? Does it resume normal functioning ok? And does the display remain on indefinately until the unit is turned back on? i.e. days, weeks, even months?

I dont have this issue thankfully, but am just curious.

Regards,

In my case, it's on a set I haven't used for years, but yes. As you say it stays on until the speaker is either unplugged from mains, or you put on the system again and it's back to normal functioning operation. Tunring it off again, might also turn of the display. Sometimes a mains disconnect is needed.

Re: penta 3 display

bayerische — Tue, 17 Jan 2012 15:09:04 GMT

Bentleyman:

Ok, I thought that's what you meant.

So, what happens with the display when the unit is turned back on again? Does it resume normal functioning ok? And does the display remain on indefinately until the unit is turned back on? i.e. days, weeks, even months?

I dont have this issue thankfully, but am just curious.

Regards,

Re: penta 3 display

Bentleyman — Tue, 17 Jan 2012 15:04:33 GMT

Ok, I thought that's what you meant.

So, what happens with the display when the unit is turned back on again? Does it resume normal functioning ok? And does the display remain on indefinately until the unit is turned back on? i.e. days, weeks, even months?

I dont have this issue thankfully, but am just curious.

Regards,