Mack,
Do you own or can you lay your hands on a logic probe or oscilloscope? You
will find your life so much easier of you have such a thing to hand. If you
have place the probe between ground and pin 1 of IC4 on the KLM 371. As you
press '1' the line should drop from a logic 1 to a 0. Check pin 14, press
button '2'. The same should happen and so on. If not check the inhibit and
address lines for data. No data? Check the connections around CN10. Still no
data? Check once again the address lines D00-D07 and the programmed i/o bus
P20 to P27 for the presence of data. I suspect you still have an issue
somewhere on the 367. I have fixed dozens of these and each one make you
want to bang your head against the wall!!
Cheers,
Andy
From:
PolySix@yahoogroups.com [mailto:
PolySix@yahoogroups.com] On Behalf Of
Justin Mammarella
Sent: 18 November 2009 03:41
To:
PolySix@yahoogroups.comSubject: Re: [PolySix] Re: Battery problems
I had to replace IC 25 and IC 23 to get my polsyix working. Erratic
light movement, noise on outputs, erratic control response. Turned
out there were some bad traces under those chips that I failed to
find even though I was confident
that I had checked everything multiple times.
On 18/11/2009, at 1:51 PM, mack_sass wrote:
> Firstly, I got my polysix off craigslist in its current, broken
> state, with little history about use or previous damage.
>
> The problems from the get go are: erratic and seemingly
> unresponsive control buttons, an no sound whatsoever when pressing
> keys (manual mode button is also unresponsive). when I press a
> control button the lights do not toggle (manual mode doesn't seem
> to do anything). There is no sound from the output jack, and a bit
> of static from the phones (I traced this around but couldn't find
> the source).
>
> I feel very confident in the repairs I have done to the CPU board,
> and have checked and rechecked all traces on a component to
> component level. I have replaces IC30 and 31 as well as the
> resistor array there...The other components visually appear
> fine...I dont really want to start replacing other parts if I don't
> have to.
>
> my first thoughts were power problems, but the power appears to be
> fine on all boards where I have checked.
>
> As per your suggestion I looked for diodes lighting up on the sound
> board, and found none to light up, perhaps I was testing wrong? Is
> there another easy way to check the voice chips?
>
> Any other easy checks that I could do to perhaps narrow down the
> search?
>
> --- In PolySix@yahoogroups.com <mailto:PolySix%40yahoogroups.com> , Paul T
<sharpfish@...> wrote:
> >
> >
> >
> > Did you try putting it in manual mode and tweaking the controls?
> (I'd assume yes of course after such a time). Can you hear any of
> the effects coming out of the output? check both phones out and
> main out? does it appear to do anything to the sound even if minor
> while switching effects or through the sound bank (even if the
> banks aren't working right).
> >
> > Obviously it could be hard to diagnose your sound output, whether
> it's completely dead, while the rest of the synth is in the usual
> 'battery broken state'. If you knew someone else with a polysix you
> could borrow their main (repaired/ok) middle PCB board, swap it in
> and see if you have any sound.
> >
> > The other thing could be dead voice chips on the right board. Do
> the diodes light up on that board (cycling through the voices) as
> you press a key repeatedly? You could/should check the voltage/
> continuity from the output jacks (inside) and trace them back to
> the components to make sure they are connected ok.
> >
> > And yes the CPU can be damaged by the leak, I think it's a bit
> rarer but depends on how bad and how far the corrosion went. Have
> you taken it out, checked the pins for damage? reseat it and try
> again? and if everything is still acting erratically of course
> triple check all your repairs for shorts (sorry that sounds
> obvious). Also check the volume pot is working (with a multimeter).
> >
> > maybe someone else will know more specifically about 'no sound'
> but it sounds to me like a number of issues caused from the damaged
> board that still need repairing and a thorough check of the audio
> path from the boards to the output.
> >
> >
> >
> > To: PolySix@yahoogroups.com <mailto:PolySix%40yahoogroups.com>
> > From: mack_sass@...
> > Date: Sat, 14 Nov 2009 01:03:12 +0000
> > Subject: [PolySix] Battery problems
> >
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> > I have been working off and on at fixing my battery issue for the
> past few months...replacing parts etc.
> >
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> >
> > I have not been able to get ANY sound from the poly six at all.
> In addition to this, the controls are unresponsive and the lights
> are erratically on or off. I suspect possible problems with the
> 8048 CPU. I have heard conflicting reports on this, but with batter
> leak damage, shouldn't I expect to heard SOMETHING when pressing keys?
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> > __________________________________________________________
> > Add your Gmail and Yahoo! Mail email accounts into Hotmail - it's
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> > http://clk.atdmt.com/UKM/go/186394592/direct/01/
> >
> > [Non-text portions of this message have been removed]
> >
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