Topic: korg poly 800 power prblem (Read 24828 times)

Circuitbenders · « **Reply #15 on:** January 11, 2011, 05:32:48 PM »

Is Q1 one of those transistors up by the power input in a TO220 case like a voltage regulator? A while back i was modding an EX800 for someone who said it wouldn't turn on after he used an AC/AC power supply on it by accident. I had a look inside and one of those, presumably Q1, actually had a hole burnt nearly all the way through it!

YashN · « **Reply #16 on:** November 18, 2013, 03:42:09 AM »

I have a puzzling problem with my Poly 800's power supply.

First, it won't power on using the 9V DC in jack. I do get power inside right after the jack, but anything beyond, e.g. the first resistor seems blank.

Secondly, I can power it on through the battery terminals, I actually extended the leads out and used a 9V battery plug so that I can easily connect 9V batteries outside of the casing. However, the synth drains the battery very, very fast (approximately 10 mins)!

Another thing I noticed is that if the battery is connected, at the same time as the PSU with the input jack, the synth won't power on: there's a short circuit somewhere...

Any pointers on what to look for would be greatly appreciated.

Circuitbenders · « **Reply #17 on:** November 18, 2013, 10:06:46 AM »

check the diode up by the DC input. I think its a 1N4001 or something.

For some reason that diode seems to fail on a very regular basis.

YashN · « **Reply #18 on:** November 20, 2013, 11:42:19 PM »

Thanks CrustyPaul, how are things?

I tested it with my multi-meter, it looks like it's okay: inf in one direction and a measure in the other, is that correct?

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Author Topic: korg poly 800 power prblem (Read 24828 times)

Circuitbenders

Re: korg poly 800 power prblem

YashN

Re: korg poly 800 power prblem

Circuitbenders

Re: korg poly 800 power prblem

YashN

Re: korg poly 800 power prblem