woodturner-fran said:I need some help guys!!
I have 2 shigas - one (my own) working perfectly. Second one made for a friend and it has been killing the mechanisms. Right from new I had to put in a second mechanism. Then last week I got a call to say the shiga wouldn't read the TOC (hit the toc button, disc spins slowly and after a longer than normal spin time, you get 00 in the display). This is the same behaviour as if the crystal was dead (using the citizen one).
So I replaced the mech and it worked fine for about a week or so. It died again on the guy today.
So it must be some fault thats killing the mech. The box its in is earthed (ie to safety earth). PS is the same as Peter Daniels, MUR860 diodes, BG cap-7808-BGcap and then into the board. Votlage is dead on 8V.
Anyone any ideas? I can't remember anyone ever having this type of problem here before.
Fran
I did kill an mechanism , i dident isolate the the regulator from the ground plate that did have the same potential as the mechanism..
woodturner-fran said:
Hi Fran
You mention that it has killed mechanisms from the beginning, do you mean before you started modify it (Which would suggest the problem is with the original board and not the PSU.) or after?
If it was the later, I would start by replacing the 7808 with a know good one before moving on to the diodes.
BTW, you mention the PSU is earthed; you could try converting the shingaclone/psu to class II (as it was originally) or try using an RCD for a while, just in case your friend's main earth bond is faulty).
Hi Dijke
dijke308 said:
15 volts! :O Where did you take your measurements, before or after the diodes?
I also wonder if these could be from a faulty batch or if it is just coincidence? Did you two buy the faulty boomboxes from a shop or from somewhere like eBay, and do you know the date of manufacture or the serial numbers? If I remember correctly the date stamped on the inside of the case of Somak's and mine were between May and September last year and both came from Argos in the UK. I don't know serial numbers.
Yeah, just to clarify, I do have 8V output.
I did wonder about the earthing and you know it might well be something worth trying out. AFAIK, I don't even need it to be earthed as the supply into it is only 12V and is through an isolation transformer.
But its only actually the case thats grounded - circuit ground doesn't connect to the case ground. But maybe theres some odd static thing going on with it.
mmmm. I might just stick in an new mechanism and remove the PS ground and just see. That would be easier than replacing the whole main board.
This is an intermittent problem. I have a hunch that this thing is AOK nearly all the time, but ocaasionally some thing happens that kills the mech. I reckon static discharge would do that right?
Fran
I did wonder about the earthing and you know it might well be something worth trying out. AFAIK, I don't even need it to be earthed as the supply into it is only 12V and is through an isolation transformer.
But its only actually the case thats grounded - circuit ground doesn't connect to the case ground. But maybe theres some odd static thing going on with it.
mmmm. I might just stick in an new mechanism and remove the PS ground and just see. That would be easier than replacing the whole main board.
This is an intermittent problem. I have a hunch that this thing is AOK nearly all the time, but ocaasionally some thing happens that kills the mech. I reckon static discharge would do that right?
Fran
mmmm The mech and case is grounded, but theres no connection between circuit ground and the case. How about I put a connection in there with back to back diodes//10R resistor//0.01nF cap?
Probably no harm to have it anyway.
Think thats what I'll do and see does it take out another mech before going at my spare EZ51 board.
thanks to all
Fran
Probably no harm to have it anyway.
Think thats what I'll do and see does it take out another mech before going at my spare EZ51 board.
thanks to all
Fran
thanks guys for all the input to the thread. Made my first `cd player last night and it worked, remote too!!
i tried no resistors on the spdif at first, but the sound was not great... i then switched to 375R in series and 100R to ground, this improved things alot. I am still not satisfied with the sound though, i removed the two caps R3 and R5 and i also removed the choke R4, and i built the psu, but only using panasonic caps.
What i'd like to know is what mods can be done next to show greatest improvements?
cheers stuart
i tried no resistors on the spdif at first, but the sound was not great... i then switched to 375R in series and 100R to ground, this improved things alot. I am still not satisfied with the sound though, i removed the two caps R3 and R5 and i also removed the choke R4, and i built the psu, but only using panasonic caps.
What i'd like to know is what mods can be done next to show greatest improvements?
cheers stuart
FAO Pocoyo
Hi Pocoyo
Do you mean; will the internal dac still work if you remove the three smd capacitors on the bottom of the CDP board?
If so the simple answer is yes.
However, you might need to add a bypass wire. The black one marked '5A' and '5B' on Okapi's PDF. (If I remember correctly it has something to do with the possibility of damaging a track when lifting 'cap 3').
Hope this helps
Pocoyo said:
Hi Pocoyo
Do you mean; will the internal dac still work if you remove the three smd capacitors on the bottom of the CDP board?
If so the simple answer is yes.
However, you might need to add a bypass wire. The black one marked '5A' and '5B' on Okapi's PDF. (If I remember correctly it has something to do with the possibility of damaging a track when lifting 'cap 3').
Hope this helps
surfstu said:
In my system setup (and considering the Shigaclone still on a plywood sheet) for the PSU, I've tried some generic brands, Nichicon and Panasonic FC's and haven't got fair enough results compared to Elna Silmic II. I was hoping the Panasonic would be close in sound quality to the Elna's but they appeared more harsh, closed and lacking in details and fluidity. The Silmic II are quite something. I strongly suggest to try them as they are easy to find and are cheap. I would be curious to hear if Black Gates were compared to the Elna here.
Just to update - I mentioned above about how the second shigai built was going through some mechanisms. Well, I did some more work on it last night and it seems something is wrong with the main board. Luckily I have a spare one to hand so I can do a swap. This time I think I will start off with Peters "minimalist" list of mods first and see how it goes.
Don't understand what happened to the board.
Fran
Don't understand what happened to the board.
Fran
Hi fellows!
I'd like to know on which capacitor I can switch from polarized to non-polarized capacitor or where I can parallel a non-polar to a polarized one.
If you have a link as a good resource that would help also as to learn the difference between a polar and NP cap and how to implement them in a circuits, I'm not too comfortable with NP in DC circuits.
Thanks and happy listening.
I'd like to know on which capacitor I can switch from polarized to non-polarized capacitor or where I can parallel a non-polar to a polarized one.
If you have a link as a good resource that would help also as to learn the difference between a polar and NP cap and how to implement them in a circuits, I'm not too comfortable with NP in DC circuits.
Thanks and happy listening.