CDROM2 repair help - no cd sound :/

gojira1954 · 10/13/2014, 08:37 AM

Hello all,
I've got a CDROM2 briefcase that doesn't give sound from the CD - plays original discs fine but not CDRs.
I have recapped the CDROM2 unit as per the excellent guide here but still no sound from the CD, game effects are fine of course.
Any advice on how to repair would be apprciated - I looked in the IFU and there are loads of caps, could they be the cause of no cd audio?
Also how to adjust the pots without a scope so the drive can play CDRs?
Thanks for your time,
Paul

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chop5 · 10/13/2014, 10:56 AM

power the cdrom by itself and play a music cd and put in some headphones. if you get sound its fine and its the ifu. the ifu caps may be fine so check for broken solder near the av plugs.

gojira1954 · 10/13/2014, 01:16 PM

Many thanks for the good advice

Audio CD plays fine... I'm off to buy yet more capacitors I guess :s
Anyone have tips on getting it to play cdrs please?

BlueBMW · 10/13/2014, 01:29 PM

Best advice for CDRs is to use high quality 650mb discs if you can. Burn at very slow speeds (1x or 2x if possible) These old drives just dont read them well at all.

gojira1954 · 10/13/2014, 01:53 PM

I bought some ridiculously expensive (for what they are) taiyo yuden archival cdrs, burnt at 1x... works okay on a duo but not on this cdrom2 :/

wolfman · 10/13/2014, 03:11 PM

Quote from: gojira1954 on 10/13/2014, 01:53 PMI bought some ridiculously expensive (for what they are) taiyo yuden archival cdrs, burnt at 1x... works okay on a duo but not on this cdrom2 :/

Try burning them at the highest speed possible, the slowest way not always works. This did the trick for me. Generally a drive works best when it is calibrated well and has all caps replaced. Then it even reads noname CDRs.

thesteve · 10/13/2014, 03:25 PM

drive condition/calibration and laser quality effect CDR play
try cal with a burned music CD

gojira1954 · 10/13/2014, 03:34 PM

I don't have an oscilloscope... I was checking out this page;
http://console5.com/wiki/Turbo_Grafx_CD-ROM_Drive
But I'm unsure which pot to mess about with out of the selection :s
What to do please?

Will try burning at 40x now too thanks

wolfman · 10/13/2014, 03:45 PM

Quote from: gojira1954 on 10/13/2014, 03:34 PMI don't have an oscilloscope... I was checking out this page;
http://console5.com/wiki/Turbo_Grafx_CD-ROM_Drive
But I'm unsure which pot to mess about with out of the selection :s
What to do please?

Will try burning at 40x now too thanks

If you are not sure that you can do it yourself try finding someone who can. Where are you based?

gojira1954 · 10/13/2014, 04:46 PM

I would like to try myself... I'm in the UK tho
Got this far with RGB modding and recapping - time to buy a USB scope?

cjameslv · 10/13/2014, 08:19 PM

Quote from: gojira1954 on 10/13/2014, 03:34 PMI don't have an oscilloscope... I was checking out this page;
http://console5.com/wiki/Turbo_Grafx_CD-ROM_Drive
But I'm unsure which pot to mess about with out of the selection :s
What to do please?

Will try burning at 40x now too thanks

If you want to get a good oscilloscope and not spend alot go this route: http://www.gabotronics.com/oscilloscopes/xprotolab-portable.htm
They work great and also have built in multimeters. Very handy tool (use it anywhere) i personally love this thing compared to my old tektronix.

Keith Courage · 10/14/2014, 01:00 AM

If it won't play CDrs then the lens is either bad or the pots need some adjustment.

regular Sony CDRs are good enough. I've never noticed any increase readability with expensive CDR discs at all. Waist of money.

thesteve · 10/14/2014, 01:07 AM

i dont expect that handheld 0.2Mhz to read the RF signal from the cd

gojira1954 · 10/14/2014, 02:15 AM

Well the taiyos were 40p a disc which is comparatively more... I also have a duo which is working okay so they weren't a waste...
On this CDROM2 originals read okay indicating the laser isn't dead so I'd like to 'adjust the pots' but don't know where to start :s
Ordered up the caps to do the IFU, I will post a pic with location/values shortly

wolfman · 10/14/2014, 02:36 AM

Quote from: thesteve on 10/14/2014, 01:07 AMi dont expect that handheld 0.2Mhz to read the RF signal from the cd

What about the DSO Nano Quad from Seeed?

gojira1954 · 10/14/2014, 08:43 AM

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thesteve · 10/14/2014, 10:38 AM

The DSO is better, but not even close to good enough

wolfman · 10/14/2014, 12:30 PM

Quote from: thesteve on 10/14/2014, 10:38 AMThe DSO is better, but not even close to good enough

Mmh...thats sad, since it is so handy...

thesteve · 10/14/2014, 12:31 PM

Agreed

Fidde_se · 10/14/2014, 01:12 PM

Since the CD-ROM2 outputs audio it's only the IFU left, which you already figured out, and while there are tons of components in the briefcase nearly all is for mixing audio (some is for power and memory/save).

It's this complex for mixing CDA + ADPCM + Standard game sounds, so there is a lot that can go wrong, but as you don't get anything it might be some of the later amps in the chain either not getting signal or no power or even gone bad, or no even getting threw if the others do or work.....

Check if IC119 is getting power (pin 1 vcc / pin 7 ground) it should be pretty late in the audio stage

Some info if needed: https://www.pcengine-fx.com/forums/index.php?topic=15656.msg319816#msg319816

thesteve · 10/14/2014, 01:48 PM

i wouldnt rule out the cdrom2 yet, but you know its mostly working

gojira1954 · 10/15/2014, 02:09 AM

Great thanks for the info, I will try the caps in the IFU first

Fidde_se · 10/15/2014, 02:56 PM

The electrolytes in the IFU is of exceptionally high quality manufactured by Elna, it will most likely not be the culprit here...

chop5 · 10/15/2014, 03:14 PM

aye fidd.
gojira where did you get the ifu from? just curious. and the ifu with pce in it plays games sound fine? i wouldnt be surprised if the pce is related to this somehow.
what you need is another cdrom to trouble shoot with the ifu and change the laser with to scratch those possibilities off the list. but in all the cdroms ive worked on i have never encountered zero sound yet game plays fine. cdroms with no sound from the headphone or low sound just need the 4.7 uf caps changed. if the pots on either the laser or board have been messed with that can cause unpredictable,unknown effects

Keith Courage · 10/15/2014, 05:31 PM

this might sound like a dumb question but have you checked the traces from the line out port on the cd drive to the expansion port?

gojira1954 · 10/15/2014, 05:40 PM

Sorry should have been clear from start - sound was very very low and just a scratching sound, not No sound...
I just changed all the caps on the IFU board - now have good sound out of the RCA connections on the IFU

One problem left for me now - no CDR playback.
I haven't messed with the pots at all yet, and don't believe they have been.
I got the briefcase setup from a friend who is the king of car boot sales - he got the ifu, cdrom & a core grafx for an unbelievable £10, seller had it in a pile of laptops :p
The core grafx had a HK fitted PAL RF mod, I ripped that out and RGB modded it for him in exchange for the IFU & cdrom as it wouldnt play cdrs & sound was gone...
Thanks for all the help and advice!

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