Clarion CD1500RG - Volume doesn't work

flavius_geniul · Joined: 02 Oct 2008 Posts: 6

Hello. I once again come to you for help, this time for a Clarion CD1500RG.
For no apparent reason when playing in my car it's front pannel froze up. Not even removing it stopped it playng so that made me realise that the problem is on the motherboard. I've removed it from the wiring harnes to stop it and opened it at home. after first cleaning the dust inside the front pannel i found rust particles (amazing i know) betwen the solderings of the face connector pins. cleaned those too and pluged the player. it started,worked perfectly but one thing still remaining: the volume button doesn't work. on the front pannel when turned the numbers kind off want to change but come back to the original volume(13).I should remaind that it's a full circle rotating button. Once again i've opened the face and cleand the insides of the volume button. Pluged again, the same problem, going crazy...
The latest thing i've done is check the function of the volume button with a voltmeter and i think it works(5 v signal when turning the button)
Help me please because it was a very good player. at least an improv to make it work, something, anything. Thank you in advance!

jts1957 · Joined: 24 Nov 2008 Posts: 2476 Location: Far, Far Away

You need to get inside and clean the p.c. board and wiper of the volume switch. Q-Tip dipped in isop. alcohol.

Guest · Posted: Sat Jan 17, 2009 9:17 pm Post subject:

Thank you for the advice but that isn't it. I've allredy cleaned the inside of the volume button by takeing it apart. As for the motherboard i've also cleaned it with alcohol. everything was cleaned with alcohol. something else please. what can it be from?

LJ · Joined: 09 Dec 2008 Posts: 47 Location: Earth

"I should remaind that it's a full circle rotating button. Once again i've opened the face and cleand the insides of the volume button. Pluged again, the same problem, going crazy... "
If 5v good, check GND connection then check the output of the rotary, the outputs should change continiously from 1 pin to other when you rotate it and also check the link from output pin to IC.
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Guest · Posted: Mon Jan 19, 2009 12:51 am Post subject:

Well, that's the problem (or i should say it isn't) beacause i've checked the connections between the button and tha IC an i have that 5V between the 2 pins entering from the front panel to the IC. I measured those 5 V directly on the IC's pins and everything good. I will take the button apart once again to be sure but i think something else is not working. maibe the IC. could that be true? could the IC be partialy damaged?
I will try to post a picture of the IC tomorrow because i don't know how to read it's part number (lots of numbers there - a Japan made NEC, fourty-something pins)

flavius_geniul · Joined: 02 Oct 2008 Posts: 6

sorry but a forgot to register the last 2 posts and that's why it says guest i think. my pc doesn't always remember automatic settings

LJ · Joined: 09 Dec 2008 Posts: 47 Location: Earth

Of course there's 2 pin output to IC and the output is 5volt, when you measure the 2 output pin, have you rotate the it? when you rotate it, is 5volt drop to 0volt ? I mean when pin 1 at 0V, pin 2 should be 5V and when you rotate it again a little, pin 1 gonna be 5V and pin 2 gonna be 0V, then rotate it again a little, pin 1 gonna be 0V and pin 2 gonna be 5V and again, again and again continuously again, pin1 should be opposite with pin2, if pin1 and pin 2 always same still at 5V when you rotate it, so maybe your rotary vol switch damage and if the rotary output between pin1 and pin2 opposite already, maybe the IC bad.
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flavius_geniul · Joined: 02 Oct 2008 Posts: 6

All u say it's happening. the 2 pin output from the button is doing exactly what u say. does that mean that the IC is probably damaged?

LJ · Joined: 09 Dec 2008 Posts: 47 Location: Earth

Have you make sure those two signal connect to IC? if you have very sure, it could be the IC problem, to make sure the IC in good condition or bad, i suggest you to find data sheet for the IC and check all of the signal that come and out from IC, maybe there's a component near IC that make the IC become malfunction.
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flavius_geniul · Joined: 02 Oct 2008 Posts: 6

I was,t able to get a picture here (don't know how) but i send youthe complete text wrutten on the IC(the big one) in hope that you provide me a datasheet or a link to it's datasheet.
Here goes:

NEC JAPAN
D178018A026
0427KY001

Tell me at least how to read the part number/model because all i've figured out is that this is a nec made in japan
And another thing i don't know: is this IC programable or ordinary?