Instrument Keyboard Faulty Screen Graphics help

[ivtec]

Hi guys; i own an Instrument keyboard Technics KN2000 that costed me a fortune back in 2000, and latley I have a Blue screen with no Graphics although still can have limited change to sound controls but but no in full do not seeing full control graphics, is there anything a can check,i notice some time i have faded graphic that soon disappear


https://technicskeyboards.com/techni...chnics-kn2000/

[diif]

Re: Instrument Keyboard Faulty Screen Graphics help

Power supply, capacitors ? Photos of the insides would help.

[ivtec]

Re: Instrument Keyboard Faulty Screen Graphics help

Power supply, capacitors ? Photos of the insides would help.

Thanka diif ; i opened it today, and inspected this board and found a tiny cap that had burned solder on one side ,i re re-solder it but no avail, i think this cap is bad,it measures 14 ohms but i think is the same ohms of the resistor on its side,i have plenty of boards with caps of this size but have no schema for this board and it has no # so i don't know what cap i should put here to try,can i try any alike in size? thanks

[Retro-Hipster]

Re: Instrument Keyboard Faulty Screen Graphics help

That is an odd looking component next to the ceramic capacitor. Does anyone know what that part is? The disk with the "153" color code? Is that just a 1.5k resistor of some kind? Maybe an inductor or some sort of MOV? I've never seen one!

And did you mean that you were thinking that the little ceramic capacitor is what was bad?

[stj]

Re: Instrument Keyboard Faulty Screen Graphics help

that photo shows alkaline damage caused by leaking batteries.

[ivtec]

Re: Instrument Keyboard Faulty Screen Graphics help

That is an odd looking component next to the ceramic capacitor. Does anyone know what that part is? The disk with the "153" color code? Is that just a 1.5k resistor of some kind? Maybe an inductor or some sort of MOV? I've never seen one!

And did you mean that you were thinking that the little ceramic capacitor is what was bad?

yes sir, the small Sm cap that was there on one side seemed the solder was burned ,i found a cap similar in size i solder it in place , now it measures about 6 ohms to opposing to
15 ohms of the other one
, but before i turn on the power, do you think it will not burn some thing else, because the keyboard has sound but since i can't see screen graphics than i'm limited to change and use all the functions and sound on the keyboard

[ivtec]

Re: Instrument Keyboard Faulty Screen Graphics help

that photo shows alkaline damage caused by leaking batteries.

Thanks Stij used alcohol to clean that burned side or the solder on the cap and re-solder it that's why it shows like that

[ivtec]

Re: Instrument Keyboard Faulty Screen Graphics help

Hi guys Update the cap replacement did not bring graphics back, i give up,this keyboards is very old and i'll keep using it with the available sounds,maybe a a ribbon cable, board or a screen will show up on ebay, so far no parts anywhere for this keyboard,i have another keyboard though, a Yamaha Psrs910

[diif]

Re: Instrument Keyboard Faulty Screen Graphics help

Ceramic capacitor values aren't indicated by their size.
Are there any markings indicating its number, it's value might be in the service manual but it's not clear from that photo.

It's ok, they are in the service manual.

It's C108 ECUV1H104ZFX 0.1uF

It is a resistor Retro_Hipster R108 ERTD2ZHK153 15kΩ

[ivtec]

Re: Instrument Keyboard Faulty Screen Graphics help

Ceramic capacitor values aren't indicated by their size.
Are there any markings indicating its number, it's value might be in the service manual but it's not clear from that photo.

It's ok, they are in the service manual.

It's C108 ECUV1H104ZFX 0.1uF

It is a resistor Retro_Hipster R108 ERTD2ZHK153 15kΩ

Thanks diif i appreciate for the Schema ,for now i gave up on the screen not being functional, still have a whole bunch of sounds, and it's not worth it to spend any money on this old keyboard, besides i suspect either the Ribbon cable or screen .,either way i still have my other Yamaha keyboard PSRS910 one of the best, so if in future i find parts on Ebay i will try to replace some, if not ,it's
ok like this for now.

[R_J]

Re: Instrument Keyboard Faulty Screen Graphics help

Did you check the voltage on that cap? It is across the -5 volt line
Did you check for VEE (-24v)

[ivtec]

Re: Instrument Keyboard Faulty Screen Graphics help

Did you check the voltage on that cap? It is across the -5 volt line
Did you check for VEE (-24v)

Thanks R_J i did not test anything since i closed the case, and don't feel like opening it again, but thanks for the info for farther tests,keyboard has a few limited sounds and i rarely use it ,.so ,cause after you are used to Yamaha PSRS910 sounds ,it sucks to here sounds from this old KN2000 keyboard ,so not worried about it,maybe i find a few parts in the web ,at the moment there are none,so i'll test volts next time i open it ,thanks