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Author Topic: Cheetah MD16 – No sound  (Read 4176 times)

TeeVee

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Cheetah MD16 – No sound
« on: January 27, 2014, 04:25:56 PM »

Hello, I have this “Cheetah MD16” which won’t spit out any sounds. First I thought it could be battery leak, which has been talked about here before. However, after opening the unit and looking into it. Then it does not look that way.

I have taken a few pictures of the unit inside:

Picture 1:


Picture 2:


Picture 3:


Picture 4:
« Last Edit: January 27, 2014, 04:27:59 PM by TeeVee »
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Circuitbenders

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Re: Cheetah MD16 – No sound
« Reply #1 on: January 27, 2014, 06:35:02 PM »

Try forcing a cold start. Theres details of how to do it in the manual, or on this forum somewhere.

If you've just put that battery in you'll probably have to leave it turned on for an hour or so and then restart it with a cold start before it'll work.

It looks like there has been a leak at some point, but its been cleaned up pretty well. Having said that, those grey wires look like repair work to bridge circuit traces damaged by a leak, although you do often see factory reworking on MD16's. I'd pull the OS and RAM chips out of their sockets and see if theres any obvious damage underneath, and find out what the grey wires are bridging.
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TeeVee

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Re: Cheetah MD16 – No sound
« Reply #2 on: January 27, 2014, 08:45:13 PM »

Concerning ”Cold Start” there is written in the manual that Cheetah MD16 checks the content at power-up and will show the message ”Cold start” if the unit detects any errors.
•   I can confirm that this unit start up with this message.
I have tried both forcing “cold start” and “Safe” and there is still no sound.

I was looking into those grey wires to find out how they was bridge:
Bot wires comes from m50734sp-10 (Link)
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Circuitbenders

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Re: Cheetah MD16 – No sound
« Reply #3 on: January 28, 2014, 09:01:23 AM »

If it comes up asking you to do a cold start every time you turn the thing on, then i'd guess either the battery isn't working or you're not doing the cold start procedure correctly. If i recall correctly you have to press shift and something else to get it to actually accept a cold start, although it will get past that point but make no noise if the cold start isn't done properly.

You can find the service manual here http://www.mediafire.com/?oni85a64jsctvaw

From the look of it, i'm not entirely sure those wires are in the correct places, but assuming they are i'd try and trace the tracks to find out if and where the break has occurred. There may be more damage around the same area.
In fact i'd advise going over the whole left hand side of the board with a magnifying glass to look for damage to the tracks.

I think this is more likely to be a cold start issue than anything to do with the hardware.

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TeeVee

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Re: Cheetah MD16 – No sound
« Reply #4 on: January 28, 2014, 11:04:21 AM »

Inside the ”Owner’s manual” is a chapter for ”Cold start”:


The combination:
“Shift + start/stop” and the display says “Cold start?”
•   It only jumps forward if I hit anything else…like voice, on…etc…
Afterward it does not ask for Cold Start…

When I hit pad 12, then it says “Electro kick” on the screen, but there are still not sound coming out of phones.

I guess there is no way around analyzing the circuit?
« Last Edit: January 28, 2014, 11:28:06 AM by TeeVee »
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Circuitbenders

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Re: Cheetah MD16 – No sound
« Reply #5 on: January 28, 2014, 06:04:41 PM »

This may sound obvious, but are you sure you have the correct jack in the right output socket? The MD16 uses stereo jacks to get two separate outputs from each socket, so you need a cable with a stereo jack on one end and two mono jacks on the other.

If this isn't the problem and cold start doesn't have any effect evn after leaving the thing on for an hour ir so without touching it, then i suspect you're going to have to try and track down a hardware fault.
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Sampler_one

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Re: Cheetah MD16 – No sound
« Reply #6 on: December 20, 2015, 02:52:00 AM »

Would anyone have a copy of the owners manual.
please msg me.
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Re: Cheetah MD16 – No sound
« Reply #7 on: December 21, 2015, 12:23:07 PM »

you could try searching for 'cheetah MD16 manual' on google.

its available as a searchable PDF with chapters from the Cykong site, which is the first result!
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