Casio HT-6000

[LawrenceR83]

Hi there, new to group and hoping for some help or advice. I have had a HT-6000 from new and i’ve lost the right hand speaker function, and also when plugged into head phones etc its lost right ear sound. 

So problem seems to be more than just the speaker as i originally thought. So my question is any advice on how to fix, and/or anyone that can fix this? I am in hereford area uk?

thanks in advance

lawrence

[Chas]

Lawrence, 

 

Welcome to the Casio Music Forum!

 

Almost certainly this is an output amp issue, or to do with the final output/ amplifying stage of the HT's sound. The HT's are actually mono, the only part that is stereo is the onboard chorus effect. With the stereo chorus off, the sound will be a mono signal sent to both left and right amp outputs.

 

The fact that you are getting output on one channel shows that the sound generation of the HT is working fine. The issue may be with the chorus unit, though I would expect the sound to come out of both channels (mono) with the chorus switched off. Therefore it's most likely to be an issue with the final output stage where the signal is sent to both the headphones and internal speakers.

 

One thing worth checking is the left and right line outs. I'm not 100% sure, but these might be output before the signal reaches the amp. If the line outs are fine, then it's almost certainly an output amp issue.

 

I have 3 x HT6000's (!), 2 working and one dead. I took the dead HT apart to see if anything obvious was amiss, nothing appeared to be so I screwed it back together again and that's as far as I got. I'm sorry I can't help you any further.

 

As to people who can repair it for you, I don't know anyone in the UK, other than a chap called Mark in SE London who fitted a KiwiTechnics Kiwi3P upgrade into my Roland JX-3P. If you want his contact details let me know and I will dig them out for you. Otherwise best to join up one of the Facebook groups such as Vintage Synth Repairs group and ask for recommendations. I am sure you will get some recommendations.

 

Good luck and let us know how you get on.

[Chas]

Here's the link to the Facebook group:

 

https://www.facebook.com/groups/vintagesynthrepair/

[Casiokid]

Try this guy:

 

https://www.youtube.com/user/markusfuller/videos

[CYBERYOGI =CO=Windler]

Check the headphone jack. There is a switch contact inside that disconnects the speaker when headphone is plugged in. If there is a bad solder joint at its input (by mechanical stress), neither that speaker nor headphone side will work.

Also a badly oxidized contact inside the jack can make the speaker fail (happens often in 6.3mm jacks of 1980th Bontempi/Farfisa keyboards), although typically the headphone would work on both channels.

[LawrenceR83]

Thanks for all your comments, i will take a look and report back. And also reach out this marcus chap if unsuccessful. 

[pianokeyjoe]

While I know this thread is old, I want to revive it for the sake of newer users in 2021. Another issue that is common at least for all the repairs I have done, is the VOLUME slider. If the volume slider is acting up it will affect the right and left of the sound with or without headphones and the biggest giveaway is the scratching sound when moving the slider up/down or side to side. Check that and clean that on any old Casio you acquire. Another thing to check is the battery compartment for leaks. If there is any old battery leak residue in the compartment, there WILL be battery acid on the inside as well and the one place the battery compartment is located near to? The VOLUME SLIDER section near to or at the top(toward the back of)the keyboard!The do not remember if my HT6000 used D cells in addition to a 9VDC power brick, but if it does, then there is a possibility that batteries where left to rot inside and the resulting damage is acid on the circuits near the volume or amp board.

[giano]

Thanks for all the inputs above: my HT6000 is finally repaired! beautiful, so warm and smooth!

My plan was put it back once repaired and go back to my trusty HT3000, but I am finding it very hard to part from it.

 

Anyway, comparing it to the HT3000 I came across an interesting difference. On the HT700/HT3000 the harmonic content of some of the waveforms changes over time depending on the DCA settings, allowing for some additional movement and more complex attack phases. But as far as I can say this does not happen on the HT6000.

 

Having an independent noise envelope this is of no practical disadvantage, and in fact it makes programming the HT6000 easier and more predictable.

[Chas]

The HT6000 is the only HT/ HZ model to have fully polyphonic filters (the others are paraphonic). This means that the HT6000 doesn't retrigger an active filter upon subsequent key presses. I wonder if this might be part of the behaviour you describe?

[giano]

Hi Chas, thanks for the hint. In fact I was simply wrong: the HT6000 has indeed harmonically evolving waves, I had just missed them. Probably I was too excited to notice!

 

 

 

 

 

[ErnieS]

Hi there Casio fans. I am new to this forum and I was hoping that someone can help me ? I have a Casio HT6000 and there is a problem with a couple of keys. When pressed they take time to sound ...and then only quietly. I have altered the velocity parameters with no difference. When connected to a midi keyboard they sound fine. Any help would be appreciated and I thank you in anticipation of a reply. Ernie.

[pianokeyjoe]

5 hours ago, ErnieS said:

Hi there Casio fans. I am new to this forum and I was hoping that someone can help me ? I have a Casio HT6000 and there is a problem with a couple of keys. When pressed they take time to sound ...and then only quietly. I have altered the velocity parameters with no difference. When connected to a midi keyboard they sound fine. Any help would be appreciated and I thank you in anticipation of a reply. Ernie.

Hi ErnieS and welcome to the Casio Forum! Under the keys, there are 2(TWO) round rubber buttons that the key triggers in sequence to get the velocity of the note and depending how fast you press the one button and THEN the other, determines velocity volume of the note. The faster you trigger them the louder the slower you trigger one then the other, the softer the sound. You either have gunk, liquid or dust build up on one or both buttons under those keys, or corrosion around and on the circuit board under the keybed under those keys. I forget if the HT6000 uses a battery compartment for main power when not using a wall wart adapter but if it DOES, then check the battery compartment for any signs of battery acid corrosion or rusting.IF there IS? Ergh! You have a problem Houston! You WILL need to take the unit apart and examine further for any battery acid corrosion issues inside the keyboard and around the keybed where you are having those key sensing issues.. Baking soda and white vinegar are what I was told would neutralize the battery acid so you can then wipe the areas affected away, and see if there is also any damage to the delicate copper traces on the circuit boards , the black carbon traces under those rubber dome buttons under the keys or even the rubber domes themselves. The other thing it could be IS the rubber dome buttons maybe worn and the carbon under them needs re carbonated(there is a kit for that now).. Others here maybe able to guide you through if you still unsure. Hope this helps and sheds some light. Midi sound module mode working great means it is at least a MECHANICAL/LOCAL issue and not a electronic/software issue but does mean repairing it and does mean more RISK.

[giano]

Hi Ernie, as pianokeyjoe writes this is most likely a mechanical issue on the keybed.

At the same time, working on the HT6000 is not very comfortable, since almost everything is soldered including the keyboard.

 

Some tips from my last repair on how you may reach the keyboard without desoldering, and some pictures to prepare yourself!

1) put the HT upside-down, unscrew the back cover and desolder the battery cables, this is really necessary for a minimum of comfort.

2) unscrew the 2 mainboards, then disconnect the ram card and keyboard connector. this are the only two connectors, all the rest is soldered!

3) turn the mainboards upside-down an let them rest on some books (see picture). Note that there may be some binders you'll have to cut, and also some aids to keep the cables in place.

 

 

4) unscrew the keyboard and put to rest upside-down on some (more!) books.

 

 

I don't remember if I took the keybed apart in this occasion.

Anyway, my reccomandation is to be patient, calm, SOBER (my best ideas for repairs seem to come after a good beer...  ) and take all the time you need. At least for me this was not an easy keyboard to work on.

 

On the good side of it, my HT6000 has shown very forgiving: I won't bother you with all I did wrong, but at the end it still worked out.

 

Good luck!

 

[ErnieS]

Hi pianokeyjoe and giano. Many thanks for your replies and advice.I am very nervous about taking the board apart (I did open it up when I bought it because it needed a good clean ) There was dirt everywhere inside and I am hoping that its just some dirt lodged under the keys. The keys involved are fairly high up on the board (5th octave C and Cblack key) but just knowing that they aren't functioning correctly just niggles away at me. I am busy just now...but maybe in a week or two I'll open it up again. Thank you both again for your help.

Ernie.