Topic: Sony MZ-R900 has bad mic input~ DIY fix?

[ercoa]

Hello folks

My MZ-R900 has crackle and drop out on the mic input. I don't know it's just dirty or in need or repair/replacement. Could someone advise me on how to approach this? I'm hesitant to just q-tip it or start taking it apart..the machine is a complicated little robot, not like cracking open a tape machine and cleaning what ever looks dirty!

thank you

[ercoa]

..anyone?

I'm guessing paid repair cost will exceed it's value, so any info to get started would be appreciated.

thank you

[fmaderjr]

I copied the following info from Sonic Studio's website years ago. I don't know if it will fix your problem or not, but you can't hurt anything by trying. Maybe Guy Sonic will chime in on its chances and with other tips.

Clean & recondition noisy mic. jacks with 91 - 99% pure isopropyl alcohol.  Repeatedly insert a headphone type plug soaked to the point of dripping (filling the alcohol bottle cap and dipping only the metal part of the mini-plug works well) into the mic. jack until any connection noise disappears.  Monitor the progress with a set of headphones while the deck is in a record function.  Rotating the microphones plug should not produce audible noise with cleaned and conditioned contacts.   Applying a contact conditioner to already cleaned plug and jack metal parts (Stereo retailer & Sonic Studios available Pro-Gold by Caig Labs works great) once to several times a year will help protect contacts from corrosion/wear and from producing noise for much longer between cleanings.     

CAUTION ADVISED: AVOID PLACING CONTACT CLEANER ON ANYTHING BUT THE METAL CONNECTOR PARTS; Plastics can be softened,  discolored, and even dissolved!  This may actually coat the very metal contacts intended for cleaning!   Fortunately,  deck input jacks are reasonably resistant to alcohol and most ‘plastic safe’ cleaners when used occasionally and with care.

WARNING: Never spray anything into the jacks on a deck.   Most Mini-DECK jacks are not the enclosed type anymore, but are open, allowing sprays to go where they can cause mechanical problems with the tape transport mechanisms and coat the tape heads.  Use the method described above with the mini-plug OR purchase a special insertable cleaning brush from CAIG or Sonic Studios (a round shaver cleaning brush may also be used with careful attention to the delicate nature of these mini-jacks).

[ercoa]

thanks!

[bugg100]

Check Guys website, there is a brush pictured that is a dental product from your corner drug store that worked wonders for my crackling MD jack.  http://www.sonicstudios.com/tips.htm

Joe

[fmaderjr]

For the life of me, I can't find any reference on his site to the dental product you mentioned. I imagine it's one of those little disposable brushes that clean between the teeth at the gum line. What product did you use? I'd like to use it for occasional preventative maintenance.

[bugg100]

Nor can I find the pic now.....  But that layout, how could you find a specific image!

You are correct about the brush, also.  The brush fits into a plastic cover for a tidy pack, came in a 3 pack.

[fmaderjr]

I think I know the one you're talking about. I have one I haven't used in a while in the bathroom. If anyone else is interested it says "Oral B" on the handle. I don't know the model # if there is one.

[ercoa]

thanks guys, very much! Even though the MD is dated, it's never nice to stop using a decent piece of gear because of a needed repair. It's been rock solid for so many years.

Given the risks of traveling with more expensive/flash based recorders (theft/media failure) it seems like a good idea to have a backup machine handy anyways.

I really appreciate the help, all.