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Vintage Synth Repair

Index last updated: 2026-04-28 23:41 UTC

Message

Re: Hammond H100

2008-04-08 by Bob

It has to be taken apart from the top and the front, actually.
The keys are screwed in from the back, but the key has to be slid 
back to disengage it from the key comb. The black panel on the front 
has to be removed to slide the key back.
What is your time frame for doing this? I was planning to repair a 
couple keys on one of the H's in the shop this weekend...I planned to 
photograph the process for my picture collection, if this would help 
you.

Bob


- In vintagesynthrepair@yahoogroups.com, "fsimon100" <fsimon001@...> 
wrote:
>
> Bob,
> Thanks. I'm certain I need to take it apart and fix it properly. 
Your 
> picures gave me great insite of the mechanics. Does it disassemble 
> from the front or start at the top and work down? 
> 
> Also the very low volume I'm assuming is unrelated because I can 
hold 
> the preset keys down to hear the organ. As I said the finals are 
> good. Where would you recommend I start scoping the audio signal.
> 
> --- In vintagesynthrepair@yahoogroups.com, "Bob" <bobmannn@> wrote:
> >
> > The preset keys can have the same problem as any of the 
keys...that 
> is 
> > that dirty contacts will prevent them from operating. I had the 
> same 
> > symptoms on my H when I first got it, and still do from time to 
> time on 
> > those keys that see little usage. Normal operation on mine 
returns 
> when 
> > I hold the Cancel key down and tap the offending key rapidly 20 
or 
> so 
> > times to clean the contacts. Maybe you will get lucky and this 
will 
> > help...at least it is worth a try.
> > As far as the key not staying down, this is not too hard to 
> > fix...however getting to the mechanism can be a challenge, 
> especially 
> > on the lower manual.
> > The mechanism is simple; there is a spring loaded bar that swings 
> on an 
> > arc under the preset keys. When a key is pressed, a 
> flexible "finger" 
> > under the key holds on to that rod. The Cancel key pushes that 
rod 
> away 
> > from the finger, and releases the preset key.
> > When the preset key no longer stays down, the "finger" is 
probably 
> worn 
> > or stuck with dried grease, and can be cleaned and/or bent 
slightly 
> to 
> > restore it, assuming the finger is not broken.
> > I can send pictures of the mechanism if you would like.
> > In order to reach the mechanism, the keys obviously need to be 
> removed.
> > If you have never done this, please let me know and I can walk 
you 
> > through it. Also, if you find broken parts during the process, 
> please 
> > let me know as I  have a couple H's in pieces out in the shop and 
> would 
> > be glad to donate what I can.
> > Bob
> > 
> > 
> > --- In vintagesynthrepair@yahoogroups.com, "fsimon100" 
<fsimon001@> 
> > wrote:
> > >
> > > H-100
> > > My preset keys won't stay engauged. How do you disassemble to 
get 
> > > underneath keys to fix. Also I have low volume if I hold them 
> down 
> > > manually. 
> > > I know final tube outputs are good but not sure where the low 
> signal 
> > > is. Do I scope out from the tonewheel somewhere then at a pre-
> amp. 
> > Like 
> > > I said I injected a tone into the final tube amps and have 
strong 
> > final 
> > > stage.
> > >
> >
>

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