Diamond Monster Sound MX300 repair.

Discussion about old sound cards, MIDI devices and sound related accessories.

Diamond Monster Sound MX300 repair.

Postby bishopcop » 2017-2-01 @ 14:00

I am trying to repair a damaged card, I have replaced the DA chip and will need to replace the op amp(tl074c) chip as well, but there is also a small smd cap above the 4x2 matrix (DA) chip(cd4052) which is marked C96. Can anyone tell me the value. I tried to measure it from another card but I gen around 12nF. There is another capacitor marked C95 which I think should be the same, and that one measures around 20nF. Maybe someone with more precise instrument can measure it?

Bish..
bishopcop
Newbie
 
Posts: 14
Joined: 2016-9-14 @ 15:34

Re: Diamond Monster Sound MX300 repair.

Postby Jepael » 2017-2-01 @ 16:02

They are just the power pin bypass caps of the cd4052, so nothing critical. I don't know the value but most likely they are 10nF or 100nF or something between those values like bypass caps usually are. It should work pretty well without it as well, it's only an analog mux and most likely it is not switched very often.
Jepael
Oldbie
 
Posts: 1195
Joined: 2005-6-15 @ 19:28
Location: Finland

Re: Diamond Monster Sound MX300 repair.

Postby bishopcop » 2017-2-01 @ 16:39

Yeah, I figured that it is not super critical, I think it is used to switch between the outputs. I received this card as faulty (it was very cheap). There was virtually no output on any of the channels. Looking at the card I noticed that the -V input on the cd4052 was burned away. I replaced this chip and figured that the amp must be shot as well. Just now I replaced the amp chip. When I put the card back in and powered on, the trace running from the -V to the c95 burned away in a pretty flame. I also found that there is a trace running from -V on the underside of the card, and that was burning too. I think there was a short underneath the chip or something, so I cut the trace on the underside to stop the short. Interestingly the output now works, I can hear everything properly on Output 1. Output 2 crackles like crazy, it seems the fault is there (it is supposed to be the headphone output).
bishopcop
Newbie
 
Posts: 14
Joined: 2016-9-14 @ 15:34


Return to Sound

Who is online

Users browsing this forum: No registered users and 3 guests