CDROM2 repair help - no cd sound :/

[gojira1954]

[thesteve]

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

[wolfman]

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

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

[thesteve]

Agreed

[Fidde_se]

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: http://www.pcenginefx.com/forums/index.php?topic=15656.msg319816#msg319816

[thesteve]

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

[gojira1954]

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

[Fidde_se]

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

[chop5]

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]

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]

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!