Sega CDX PCB Component Rotted

Hello all

Due to there being no service manual for the CDX I'm having to ask for help identifying this component on the laser PCB, I'm hoping it's just a basic fuse I can bridge but want to make sure first, the component in question is 16.9C42

Thanks in advance!

 

Looks like an oscillator crystal to me, but I don't know anything about reading their labels. @TriMesh might know.

 

Thanks for the reply, I wonder if a 16mhz Crystal Oscillator would work? Yeah there isn't much @TriMesh doesn't know

 

Yeah IIRC X is used to designate crystals (XTAL)

 

Does anyone know if a 16MHZ Oscillator would work?

 

I think its a 16.9Mhz not 16Mhz.

 

Definitely a 16.9mhz crystal. I would desolder it and clean up the through holes to assess damage. If the points are too far gone, there seems to be some vias directly linked to the through holes which u could use as alternative solder points. The oscillator may still work, it might just be a corroded connection.

 

Has no one reversed engineered this board even a little?

 

That is a 16.9 MHz quartz crystal (HC49/US), though highly unusual that it is floating that high off the circuit board. The closest crystal you will commonly find is 16.93 MHz on most online electronic distributors (likely the exact part). You may want to verify if there is a tiny capacitor on each of the two traces connected to that crystal (check opposite side of the board) - if there are no capacitors then the crystal with the lowest ESR and better frequency stability is the optimal choice.

 

The theoretical frequency is going to be 16.9344MHz - it's a standard frequency for the reference clock on CD players using a 24 bit output format. It's 4 times the output bit rate (44.1kHz * 2 channels * 24 bits). Most of them are listed as 16.934MHz, and typically those HC49/4H package xtals have a 20 or 30pF load capacitance.

Edited to put the correct result in

 

I’m going to try a re-solder and will also report back on the possible capisator on the traces

 

Re-solder to no avail, still stuck on "checking disc" and stays that way until the disc completely stops. Seems to be capacitors on the traces yes.

Does anyone know a compatible oscillator?

Thanks for all the replies

 

This one should work, although it has straight leads rather than kinked:

https://www.mouser.hk/ProductDetail...LFXTAL019708Bulk/?qs=e4/AndAAwgJYBaY8pNnfWg==

 

Thanks as always TriMesh

EDIT: 16pence for the oscillator £12 for delivery... beyond ridiculous, any alternatives?

 

Have you cleaned the corroded through holes and checked for continuity? Have u ruled out a failing laser? Do u have pictures of the top and bottom of the pcb near the oscillator and associated IC? It would be good to check the crystal with an oscilloscope just to definately rule it out.

 

50pcs/lot Crystal Oscillator 18.9375MHz 18.9375 MHz 18.9375M Hz Mini Passive Resonator Quartz HC-49S
50pcs/lot Crystal Oscillator 18.9375MHz 18.9375 MHz 18.9375M Hz Mini Passive Resonator Quartz HC-49S might work fine
http://s.aliexpress.com/2M7NjARN
(from AliExpress Android)

 

Those wont do much good.

 

O sorry wron freq. But there is a lot of them on ali. Might be able to find one.

 

I just had a look, and I'm not having much luck - RS don't even stock this frequency, Farnell are only showing "US Stock" (I.E. Newark) and Digikey are about the same delivery cost as Mouser. If I think of any more possible suppliers I will get back to you.

I could add the part to one of my Mouser orders and send it to you - but unfortunately I'm in Hong Kong and the only cheap shipping method would be (slow) regular airmail.

 

You have posted a link to 19.6mhz, the original was 16.9.

UK stock:
https://www.ebay.co.uk/itm/CRYSTAL-...766913?hash=item3f88b906c1:g:7ukAAOSw7RdZ16Lk

Or 20 from china:
https://www.ebay.co.uk/itm/20-Pcs-H...854109?hash=item43e0b6535d:g:w1EAAOSwrP9Z1V0X