VOGONS


First post, by Ripthron

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I googled a little bit and noticed that in this forum some people had this model, so I decided to ask here

I found one relatively for cheap, so I ended up buying. When I turned on the device I noticed that the display looked a little strange, the information was only readable if I looked at it from strange angles.
I looked for videos on YouTube and I saw people making videos of the module with strange angles.

Now comes the question: Do I have a module with a broken display or does it have a really bad display? Any help will be grateful!

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Reply 1 of 16, by yawetaG

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That looks like someone adjusted the contrast wrongly on the display. Check the manual (available from Kawai USA) to see whether it can be adjusted (it will either be a knob on the module or a setting in the menus).

It can also mean a failed display, although normally when they fade over time you don't see much at all... In that case you'll have to replace the display unit (en hope Kawai didn't use a custom display).

Reply 2 of 16, by Ripthron

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yawetaG wrote on 2021-02-01, 08:17:

That looks like someone adjusted the contrast wrongly on the display. Check the manual (available from Kawai USA) to see whether it can be adjusted (it will either be a knob on the module or a setting in the menus).

It can also mean a failed display, although normally when they fade over time you don't see much at all... In that case you'll have to replace the display unit (en hope Kawai didn't use a custom display).

Yeah, that was my first assumption, I looked in the manual and I really don't see any mention of display brightness or contrast .
I contacted the seller and he said that he has an option to adjust the display, but he was not specific and indicated the same manual that I saw.

Reply 6 of 16, by Ripthron

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sf78 wrote on 2021-02-02, 10:52:

Open it up and see if there is this type of trim pot that could adjust the brightness.

trim.jpg

I thought that could be it and I asked the seller if it didn't have an internal slider/knob/pot and he said no, it was through the panel.
He also said he would ask a friend who has a similar device how to change the display contrast.

I'll wait for today, if I don't get an answer I'll open the device and look for a pot / slider / knob.

Last edited by Ripthron on 2021-02-02, 13:37. Edited 1 time in total.

Reply 8 of 16, by yawetaG

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Ripthron wrote on 2021-02-02, 12:51:
I thought that could be it and I asked the seller if it didn't have an internal slider/knob/pot and he said no, it was through t […]
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sf78 wrote on 2021-02-02, 10:52:

Open it up and see if there is this type of trim pot that could adjust the brightness.

trim.jpg

I thought that could be it and I asked the seller if it didn't have an internal slider/knob/pot and he said no, it was through the panel.
He also said he would ask a friend who has a similar device how to change the display contrast.

I'll wait for today, if I don't get an answer I'll open the device and look for a pot / slider / knob.

Just be careful because I've seen similar types of pot to adjust settings that when improperly adjusted can seriously screw up how a synth module works...

Reply 9 of 16, by Ripthron

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sf78 wrote on 2021-02-02, 13:30:

It could also be a solder joint or capacitor issue. Better to open it and check everything anyway.

I opened it and didn't see anything that could be used to adjust the display.
I couldn't remove the secondary pcb, but I looked with the camera and didn't see anything that looks like a trim pot or a dial. I doubt it is between the display's pcb and faceplate

yawetaG wrote on 2021-02-05, 21:11:
Ripthron wrote on 2021-02-02, 12:51:
I thought that could be it and I asked the seller if it didn't have an internal slider/knob/pot and he said no, it was through t […]
Show full quote
sf78 wrote on 2021-02-02, 10:52:

Open it up and see if there is this type of trim pot that could adjust the brightness.

trim.jpg

I thought that could be it and I asked the seller if it didn't have an internal slider/knob/pot and he said no, it was through the panel.
He also said he would ask a friend who has a similar device how to change the display contrast.

I'll wait for today, if I don't get an answer I'll open the device and look for a pot / slider / knob.

Just be careful because I've seen similar types of pot to adjust settings that when improperly adjusted can seriously screw up how a synth module works...

Don't worry, I'll leave it the way it is. At least it's working well.

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Reply 10 of 16, by sf78

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Ripthron wrote on 2021-02-06, 14:31:

I opened it and didn't see anything that could be used to adjust the display.
I couldn't remove the secondary pcb, but I looked with the camera and didn't see anything that looks like a trim pot or a dial. I doubt it is between the display's pcb and faceplate

Yeah, I wouldn't worry about it too much. You'd have to remove the whole lower PCB from the case to examine the solder joints anyway. It could be a power issue with the display unit or a voltage regulator somewhere, but without measuring it's just random guessing. If it works and the display doesn't bother you too much, I'd ask for a (partial) refund from the seller if it was sold as working.

Reply 11 of 16, by Ripthron

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sf78 wrote on 2021-02-08, 10:35:
Ripthron wrote on 2021-02-06, 14:31:

I opened it and didn't see anything that could be used to adjust the display.
I couldn't remove the secondary pcb, but I looked with the camera and didn't see anything that looks like a trim pot or a dial. I doubt it is between the display's pcb and faceplate

Yeah, I wouldn't worry about it too much. You'd have to remove the whole lower PCB from the case to examine the solder joints anyway. It could be a power issue with the display unit or a voltage regulator somewhere, but without measuring it's just random guessing. If it works and the display doesn't bother you too much, I'd ask for a (partial) refund from the seller if it was sold as working.

I'm starting to think that the display is just really bad.

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Reply 12 of 16, by Salient

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The Kawai Gmega uses a generic Hitachi HD4478 based 16x2 display afaik. Any of those from AliExpress will probably do. Maybe you'd have to fiddle a little to align it (don't know if the screw holes match) but it should be possible.
Did the same twice with both my Roland RA-50's 😀

MIDI comparison website: << Wavetable.nl >>
(Always) looking for: Any Wavetable daughterboard, MIDI Module (GM/GS/XG)

Reply 13 of 16, by sf78

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Judging by these videos:

https://www.youtube.com/watch?v=kkFE1025hEw

https://www.youtube.com/watch?v=7IsOGGJK5xY

The display should probably look like that. There are also those videos you mentioned that show contrast problems.

Reply 15 of 16, by Ripthron

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Salient wrote on 2021-02-08, 18:44:

The Kawai Gmega uses a generic Hitachi HD4478 based 16x2 display afaik. Any of those from AliExpress will probably do. Maybe you'd have to fiddle a little to align it (don't know if the screw holes match) but it should be possible.
Did the same twice with both my Roland RA-50's 😀

Thanks for the info. I probably ask someone to replace it

sf78 wrote on 2021-02-09, 10:02:
Judging by these videos: […]
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Judging by these videos:

https://www.youtube.com/watch?v=kkFE1025hEw

https://www.youtube.com/watch?v=7IsOGGJK5xY

The display should probably look like that. There are also those videos you mentioned that show contrast problems.

Yeah... it could be the camera angle too...

Rawit wrote on 2021-02-09, 14:23:

You are using the correct power supply?

Not exactly, it's from Kawai but has a lower amperage, it's the one the previous owner used. I tested it with the MT-32 power supply, which has specifications similar to the Kawai GMEGA psu, but unfortunately it didn't change anything.
I already bought a new one, I'm waiting to be delivered, but I doubt it will change anything.