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Vintage Synth Repair

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Siel DK70 Not powering up-- anyone have a service manual?

Siel DK70 Not powering up-- anyone have a service manual?

2010-09-24 by Mark

I was wondering if any of you had a schematic or a service manual of this synth. When I switch the keyboard on, I hear a faint click in the psu section, but the keyboard does not power up. There are four test points conveniently located near the psu board to test voltage. I've hooked them up to a oscilloscope and they are reading the proper voltages (+12, 0V, +5 and -12). Siel was very helpful in the development of this synth, they labeled the proper voltages here on the pcb.

However, when I try the test points to the right of the circuit board, I get no voltage readings at all. There are no voltages listed on the pcb in this section. These test points are near the BBD chip and the DAC. There is no power on the cpu board at all. I replaced the two larger caps near the power input but not any of the other electros. There are no visible signs of damage to the pcb at all or any components.

What I hate to think about is that it could be a stupid diode or a regulator somewhere that is dead. I'd really like to get this thing powered up, lol.

RE: [vintagesynthrepair] Siel DK70 Not powering up-- anyone have a service manual?

2010-09-24 by timothy kosiorek

I've got a DK70 and a service manual ,I'll need to look around for it but I can send you some scans of the boards and circuits you need,just let me know which ones you want,reply to me at tkosiorek@... so I can reply with the attachments.
Tim K.




> To: vintagesynthrepair@yahoogroups.com
> From: casiotone1331@...
> Date: Fri, 24 Sep 2010 15:40:57 +0000
> Subject: [vintagesynthrepair] Siel DK70 Not powering up-- anyone have a service manual?
>
> I was wondering if any of you had a schematic or a service manual of this synth. When I switch the keyboard on, I hear a faint click in the psu section, but the keyboard does not power up. There are four test points conveniently located near the psu board to test voltage. I've hooked them up to a oscilloscope and they are reading the proper voltages (+12, 0V, +5 and -12). Siel was very helpful in the development of this synth, they labeled the proper voltages here on the pcb.
>
> However, when I try the test points to the right of the circuit board, I get no voltage readings at all. There are no voltages listed on the pcb in this section. These test points are near the BBD chip and the DAC. There is no power on the cpu board at all. I replaced the two larger caps near the power input but not any of the other electros. There are no visible signs of damage to the pcb at all or any components.
>
> What I hate to think about is that it could be a stupid diode or a regulator somewhere that is dead. I'd really like to get this thing powered up, lol.
>
>
>
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Re: Siel DK70 Not powering up-- anyone have a service manual?

2010-09-25 by Scott

--- In vintagesynthrepair@yahoogroups.com, timothy kosiorek <tkosiorek@...> wrote:
>
> 
> I've got a DK70 and a service manual ,I'll need to look around for it but I can send you some scans of the boards and circuits you need,just let me know which ones you want,reply to me at tkosiorek@... so I can reply with the attachments.
> Tim K.
> 
> 
>  
>Check the cabling from the power supply to the other PCB. Continuity test

Check for AC ripple on the Electrolytics on the P.S. board. Any more than 5% of the DC not so good.

Check rectifier diodes with a meter.

Re: Siel DK70 Not powering up-- anyone have a service manual?

2010-09-25 by Scott

--- In vintagesynthrepair@yahoogroups.com, timothy kosiorek <tkosiorek@...> wrote:
Show quoted textHide quoted text
>
> 
> I've got a DK70 and a service manual ,I'll need to look around for it but I can send you some scans of the boards and circuits you need,just let me know which ones you want,reply to me at tkosiorek@... so I can reply with the attachments.
> Tim K.
> 
> 
>  
> 
> > To: vintagesynthrepair@yahoogroups.com
> > From: casiotone1331@...
> > Date: Fri, 24 Sep 2010 15:40:57 +0000
> > Subject: [vintagesynthrepair] Siel DK70 Not powering up-- anyone have a service manual?
> > 
> > I was wondering if any of you had a schematic or a service manual of this synth. When I switch the keyboard on, I hear a faint click in the psu section, but the keyboard does not power up. There are four test points conveniently located near the psu board to test voltage. I've hooked them up to a oscilloscope and they are reading the proper voltages (+12, 0V, +5 and -12). Siel was very helpful in the development of this synth, they labeled the proper voltages here on the pcb.
> > 
> > However, when I try the test points to the right of the circuit board, I get no voltage readings at all. There are no voltages listed on the pcb in this section. These test points are near the BBD chip and the DAC. There is no power on the cpu board at all. I replaced the two larger caps near the power input but not any of the other electros. There are no visible signs of damage to the pcb at all or any components.
> > 
> > What I hate to think about is that it could be a stupid diode or a regulator somewhere that is dead. I'd really like to get this thing powered up, lol.
> > 
> > 
> > 
> > ------------------------------------
> > 
> > Yahoo! Groups Links
> > 
> > 
> >There might be a Crumar equivalent for this model if that helps
>

Re: Siel DK70 Not powering up-- anyone have a service manual?

2010-09-25 by Mark

I'll check those when I get home. This model takes the standard wall-wart, 12VDC, 1.5a.

It also doesn't power up when fresh batteries are installed... I don't know if this helps. I had some luck resurrecting a dead Yamaha DX21 last week, but this has been stumping me for a while now. Reminds me of the old rusty Crumar T1/C that kept me in the basement for months...

--- In vintagesynthrepair@yahoogroups.com, "Scott" <painintheamp@...> wrote:
Show quoted textHide quoted text
>
> 
> 
> --- In vintagesynthrepair@yahoogroups.com, timothy kosiorek <tkosiorek@> wrote:
> >
> > 
> > I've got a DK70 and a service manual ,I'll need to look around for it but I can send you some scans of the boards and circuits you need,just let me know which ones you want,reply to me at tkosiorek@ so I can reply with the attachments.
> > Tim K.
> > 
> > 
> >  
> > 
> > > To: vintagesynthrepair@yahoogroups.com
> > > From: casiotone1331@
> > > Date: Fri, 24 Sep 2010 15:40:57 +0000
> > > Subject: [vintagesynthrepair] Siel DK70 Not powering up-- anyone have a service manual?
> > > 
> > > I was wondering if any of you had a schematic or a service manual of this synth. When I switch the keyboard on, I hear a faint click in the psu section, but the keyboard does not power up. There are four test points conveniently located near the psu board to test voltage. I've hooked them up to a oscilloscope and they are reading the proper voltages (+12, 0V, +5 and -12). Siel was very helpful in the development of this synth, they labeled the proper voltages here on the pcb.
> > > 
> > > However, when I try the test points to the right of the circuit board, I get no voltage readings at all. There are no voltages listed on the pcb in this section. These test points are near the BBD chip and the DAC. There is no power on the cpu board at all. I replaced the two larger caps near the power input but not any of the other electros. There are no visible signs of damage to the pcb at all or any components.
> > > 
> > > What I hate to think about is that it could be a stupid diode or a regulator somewhere that is dead. I'd really like to get this thing powered up, lol.
> > > 
> > > 
> > > 
> > > ------------------------------------
> > > 
> > > Yahoo! Groups Links
> > > 
> > > 
> > >There might be a Crumar equivalent for this model if that helps
> >
>

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