Solved Erratic Problems In Micromega CD-10 Silver CD Player
This unit received in November, 2024 re-visited me in December, 2025 with the complaint of erratic problems and not reading any of the disks. I have made a report of my earlier work on this, which can be seen here:
https://jestineyong.com/restored-a-tampered-cd-player-micromega-cd-10-silver/
I will be providing only images relevant to the problems and rectification done this time. Checking of the player confirmed the complaint lodged and my investigation started first by observing the problems carefully by loading atleast ten different CDs. One of the CDs was detected and played. All others showed either no disc or indication of error.
Whenever display of error was shown, the eject button won’t work, though showing ‘opening’. But when we press standby, the CD will get ejected. These are erratic problems mainly caused by impure DC primarily. This can also happen due to software issue. But in order to obviate the filter problems I checked the main filter caps on the system board and this is what I found:
As you can from the arrow, a filter capacitor was found bulgy in the front panel LCD/Key control board. The main filter capacitors were higher than indicated. Any capacitor that shows higher value than what is printed on it, is certainly an indication of degradation. In order to ensure that my meter is not the culprit, I measured a 4700uF cap and found it to be reading around 4250 which is due to the 10% tolerance. All normal caps should show a little below the printed value. By the way, any of you have wondered how a multimeter measures the capacitance? A fixed voltage is pumped into the cap and it checks the discharge time to determine its capacity. The standard comparison chart is already available in the program of the Multimeter. That’s why capacitance measurement is always a bit slow. The screen will stay still or go blank with some running dots until the process is over, before showing the result. Before these Digital Multimeters came to the market, older technicians like me used to measure the capacitor with an analogue Multimeter selecting appropriate ohms range after discharging the cap fully. The needle will go and hit at the extreme right and slowly return to the left (from full scale deflection to zero). If the return is not smooth and steady or wanders back to FSD (full scale deflection), the cap is defective. Depending on the value, we have to select the range that shows a quick reading. Higher value caps should return very, very slowly. This manual method has to be learnt from practice. These details are for the beginners and not meant for stalwarts in the field of electronics.
I replaced all these electrolytic capacitors and a few of the tantalum caps also, though all values were not available. I replaced all the aluminium SMD caps, as the values were totally out. A couple of capacitors came off when I tried to shake it and remove it instead of desoldering, the method of which has been explained by me several times in the past.
So, that was the condition of the dry solder on the system board. I also added 10uF/63V caps at the in and out points of regulator ICs, in order to compensate for any degraded tantalum caps already found fixed.
Next, I took up the mechanism control board and cleared the dry solder of the 3.3V regulator IC and added two 10/35V tantalum caps; one at the V-in and another at the V-out. Cleaned and lubricated the connectors and also the strip wires. Since I noticed that the sliding motor was sluggish, applied silicone grease after cleaning the rod on which the eye unit moves to and fro. I also cleaned the lens using cotton buds dabbed with IPA, taking care not to apply too much pressure. After checking and rechecking all solder work done and the polarity of the caps, I noticed that the tantalum caps were wrongly soldered by me mistaking the centre point as ground. In 1117 regulator ICs, the third pin is V-In, 2nd pin is V-out which is connected to the heat sink and the first pin is ground, provided it is a fixed one. If it is an adjustable type, the first pin will have resistors from ground, sometimes even from positive side to fix the desired output. The picture what you are going to see below is before I rectified the mistake done by me, as I forgot to click it afterwards. Now, Let us see some pictures:
The mechanism driver board is CD80 of Bluetiger, which is a world famous brand for such boards. I could obtain the schematic also for this board from the web. Though I tried copying the link, it could not be done properly. Any search with brand name, Bluetiger and CD80 would fetch it. After finishing the work I reassembled the boards and applied power and loaded several CDs, most of which were played very well. Let us have a look of it working happily:
Mission accomplished with vigor and enthusiasm and the collection bag sensed its presence and gulped it.
Following is the CD-80 board found in the schematic.
This article was prepared for you by Parasuraman Subramanian from India. He is 76 years old and has more than 30 years’ experience in handling antique equipment like Valve Radio, Amps, Reel Tape Recorders and currently studying latest tech-classes conducted by Kerala State Electronics Technicians’ Association. He has done graduation in BBA degree, private diploma in Radio Engineering and retired as MD of a USA company. Presently working as Consultant to Hospital and other institutions.
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