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NEC TG-16/TE/TurboDuo => TG/PCE Repair/Mod Discussion => Topic started by: turbokon on July 26, 2014, 05:20:39 PM
Title: Turbo CD-Rom2 unit making strange noise
Post by: turbokon on July 26, 2014, 05:20:39 PM
Here is a new one on me. I have this cd-rom2 unit that is making strange noise, which sounds like dial-up, during loading. It has new gears and a few caps replaced. CD games seems to work fine other then the noise between loads. Any ideas?
Title: Re: Turbo CD-Rom2 unit making strange noise
Post by: Keith Courage on July 26, 2014, 09:41:55 PM
It's a resister in the middle of the motherboard. Check on the underside of the screw that holds the board down. Sometimes this resister can get smashed/cracked during shipment. I've encountered this 4 times now myself.
Usually it's the one I circled in this pic. http://postimg.org/image/wcbf11dqz/
Title: Re: Turbo CD-Rom2 unit making strange noise
Post by: Bernie on July 27, 2014, 03:10:23 AM
Is this the one you got from me?
Title: Re: Turbo CD-Rom2 unit making strange noise
Post by: turbokon on July 27, 2014, 03:53:16 AM
Keithcourage, you hit the nail right on the head. Resistor 168 was damaged. It was a 10k ohm resister. Replaced it and it fixed the problem.
(http://img.tapatalk.com/d/14/07/27/esuzamup.jpg)
Title: Re: Turbo CD-Rom2 unit making strange noise
Post by: Ninja16608 on July 27, 2014, 07:22:32 AM
I said it before and I'll say it again KC you are the man, just by listening to it you knew what the problem was ahhahaha love this place!!!!!!!!!!!!!!!!!!!!! Glad to hear ya got it taken care of Turbokon.
Title: Re: Turbo CD-Rom2 unit making strange noise
Post by: NightWolve on July 27, 2014, 07:21:20 PM
Huh, interesting, the resistor is the most reliable electrical component too, it's the last thing that'd you look for in troubleshooting. That it's in a bad spot or something and physically gets smashed/banged makes sense as to why you're seeing early failure. Good to know about then, so 10 KOhms at location R168. Yeah, this is the first troubleshooting thread I've ever seen here pointing to a resistor, as far as I can remember at least.
Title: Re: Turbo CD-Rom2 unit making strange noise
Post by: turbokon on July 28, 2014, 12:54:30 AM
Huh, interesting, the resistor is the most reliable electrical component too, it's the last thing that'd you look for in troubleshooting. That it's in a bad spot or something and physically gets smashed/banged makes sense as to why you're seeing early failure. Good to know about then, so 10 KOhms at location R168. Yeah, this is the first troubleshooting thread I've ever seen here pointing to a resistor, as far as I can remember at least.
Actually this is the second unit I worked on that was caused by a bad or missing resistor. I worked on a duo a couple of years ago with memory save issues. Come to found out its memory save chip had an open circuit due to a missing resistor.
Title: Re: Turbo CD-Rom2 unit making strange noise
Post by: Ninja16608 on July 28, 2014, 03:24:51 AM
Huh, interesting, the resistor is the most reliable electrical component too, it's the last thing that'd you look for in troubleshooting. That it's in a bad spot or something and physically gets smashed/banged makes sense as to why you're seeing early failure. Good to know about then, so 10 KOhms at location R168. Yeah, this is the first troubleshooting thread I've ever seen here pointing to a resistor, as far as I can remember at least.
Yeah It is very rare to hear about a resistor in any device lol. I guess when the screw crushes it, it takes a toll. Seems to me like NEC didn't think that one through or no one caught it.
Title: Re: Turbo CD-Rom2 unit making strange noise
Post by: turbokon on July 28, 2014, 05:26:18 AM
Come to think of it, my LT that I just recapped had cap leakages affecting a couple of resistors. I couldn't get any power to the LCD after recapping. After removing those resistors and cleaning underneath them, LCD fired right up.
I've also came across a few GT/TE where the small smd resistors (I think sizes 0405) by hu6280 that got damaged by whomever tried to recapped them before me. These resistors affected the on board controller function.
Title: Re: Turbo CD-Rom2 unit making strange noise
Post by: Marll on November 05, 2014, 08:26:06 AM
I've had this issue (though not as horrible sounding as that vid) since day 1 with my CD when I got it in 91. I thought this was just the way they sounded.
Had a buddy buy another CD off of craigslist a couple years ago and it was silent, it was WEIRD to hear that...almost wrong :lol:
I think that I'll probably fix it though since it's not supposed to be like that when I start doing a few more mods to my system.
Title: Re: Turbo CD-Rom2 unit making strange noise
Post by: Marll on November 12, 2014, 07:51:43 AM
So, those that have repaired this issue before, is there any reason that you specifically need to use a surface mount resistor? I was planning on doing this soon, but could only find some really small 10k ohm through hole type resistors. any reason the leads couldn't be cut short, laid flat and soldered to the pads?
Title: Re: Turbo CD-Rom2 unit making strange noise
Post by: turbokon on November 12, 2014, 11:11:39 AM
So, those that have repaired this issue before, is there any reason that you specifically need to use a surface mount resistor? I was planning on doing this soon, but could only find some really small 10k ohm through hole type resistors. any reason the leads couldn't be cut short, laid flat and soldered to the pads?
It will be ok to use the leaded resistor as long as you have enough room to solder the leads to the pads.
Title: Re: Turbo CD-Rom2 unit making strange noise
Post by: Marll on November 13, 2014, 05:04:53 PM
Cool thanks, I figured that was the case, now just need to open up the unit to see if that's the case.
If not, where is it that most of you guys are ordering your parts for these types of repairs?
Title: Re: Turbo CD-Rom2 unit making strange noise
Post by: Keith Courage on November 13, 2014, 09:44:21 PM
Most of time with surface mount resisters I end up taken them off of other older CD drives or other dead video game systems instead of ordering new. Sorry, that doesn't help you out with where to order from.
Title: Re: Turbo CD-Rom2 unit making strange noise
Post by: crans on November 14, 2014, 04:39:57 AM
i use mouser or digikey but price is not great if you just need one of something.
Title: Re: Turbo CD-Rom2 unit making strange noise
Post by: Fidde_se on November 14, 2014, 05:39:01 AM
Tayda is great, they're like HongKong based but ships out extremely fast, takes 6 days usually so I would guess the same for the US, they only have 0805 in surface mounted though..