Partial Restoration Of Philips Three-In-One
The model number of this set is Philips AZ1047/94 and this is a three-in-one set, i.e, CD-Radio-Tape Player. The set was brought to me with the complaint that CD was not working, there was a lot of noise in Radio and tape was not working.
On visual inspection, I could find a crack on the cabinet indicating a fall, and on opening the set, I could make out that the set was not opened for many years. Dirt and cob-web had got collected inside the set.
After thorough cleaning using Blower and brushes, I dismantled the set completely. I also cleaned the inside with cloth, wherever it was possible. While dismantling, I noticed that the damage had mainly affected the tape mechanism side, and the motor had come out loose. A couple of lugs were broken.
Patched-up dry solder points, lubricated the connectors and assembled the PCBs outside, feeding its own power supply. The noise due to unclean volume control was solved. But while playing the Tape Recorder, there indeed was a noise, which was traced to a couple of SMD capacitors on the recording path, using isolation method. That means, cutting the track, by removing jumper wires going to it. I could conclude it was from the recording wire, only by removing the wires other than the power supply, one by one from the connector and playing.
This is an easy short-cut method to isolate problems in a board. But the noise continued even after replacing the SMD caps. Then I knew that it has got something to do with the recording switch. Though I cleaned it thoroughly, using WD40 and pressing it in and out several times, this problem could not be solved. After verifying with the customer, who said that he never used Recording on tape and that can be disabled, I slid out the wire from its connector and the noise was missing. But there was no problem in playing at all.
After ensuring that the Tape was working very well, I turned my attention to Radio side. Did lubrication of connector. Found that it was working very well.
Then took up the CD part. This was difficult, as the flexible strip connecting the Eye unit to main PCB was too short. So, after using a bit long strip, I turned it on and noticed that CD was playing, but no audio output was coming. Though I tried to get the datasheet of the IC used in it, I could not succeed. I looked for any dry solder, bad components etc. I even reflowed the IC. I also used my Oscilloscope to check whether the audio was coming out from the IC, in the portions, where the digital output was connected to analogue output of the audio. It was missing. It was more or less a complaint within the IC itself, even though it was not getting hot. Here you can have look at this:
Since the number was not clear enough, I even tried different possible combinations, but in vain.
Once again, referred to the customer, who said he was happy if the set was working in Radio and Tape and he had another good CD player and he never used this. As he himself was not very keen in getting the CD portion restored, and replacement IC was not available, and more importantly, I also was hesitant in replacing this IC due to lack of such experience, I dropped it. So, reassembled the set. Fixed a new Antenna in place of only the stub of the old one. Set was working very well.
Thus this was added to my completed list, but not to the satisfaction list!
This article was prepared for you by Parasuraman Subramanian from India. He is 70 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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Mark
April 29, 2020 at 3:51 pm
Well done Parasuraman,
Sometimes we can only go so far & although it can be frustrating, it's good that we can get a unit up and running again, even if not all systems are working.
Parasuraman S
April 29, 2020 at 9:47 pm
Many thanks for your encouraging words. Yes, it is a part of our electronic service life and we have to accept it.
viren kr
May 5, 2021 at 4:54 pm
i have Philips mp3 cd playback . model number -AZ1047/94.
In this device has not given output properly audio sound . what was the problem and give solution.pls
Alex Kent
April 29, 2020 at 4:56 pm
Great work!
I had a similar experience, with a combo' unit (radio, tape, multi-CD). I was able o get part of the device working (multi-CD), and that satisfied the customer (who did not use tapes).
I also, not satisfied, but customer happy!
Sometimes, it's more important to satisfy the customer, than to be 100% effective.
Parasuraman S
April 29, 2020 at 9:49 pm
Yes, we cannot insist that everything should turn favorably. Many such set backs teach us much more lessons than success. That is the hidden satisfaction in these type of incidents.
Alex Kent
April 29, 2020 at 5:21 pm
For future, I think this is the chip, you have been looking for;
TC94A77FG
Parasuraman S
April 29, 2020 at 9:51 pm
Oh! Many thanks for your help and the link. I have just downloaded the pdf file. Shall study. Probably it could be the one.
Waleed Rishmawi
April 29, 2020 at 6:29 pm
Good job on a well done repair. Keep up the good work and have a blessed day
Albert van Bemmelen
April 29, 2020 at 7:25 pm
I'm sure you did your upmost best in restoring this Philips audio combination! In my humble opinion these sets are not even made serviceable. Opening and taking everything apart carefully is hard enough in these engineer unfriendly designs. Why I not even would bother to buy these combi's ever!
I think the way how they made them in the 70's and 80's, everything apart in its own metal rectangular box, stackable on top of each other, and with easy external cable connections, plus the service friendly design, were the best!
And these sets almost never need any service either!
Parasuraman S
April 29, 2020 at 9:54 pm
Yes, you are right. These are not made service friendly. Probably priced cheap for use and throw. Anyhow, we will not let anything reach the dump yard! That's the vow taken by hobbyists like us! The stackable separate system was good for servicing, with a majestic look too.
LLOYD
April 29, 2020 at 7:28 pm
good article
Parasuraman S
April 29, 2020 at 9:54 pm
Many thanks!
Don Oser
April 29, 2020 at 9:41 pm
You did the best you could and saved it from the landfills.
Parasuraman S
April 29, 2020 at 9:55 pm
Yes, you are right. That's all what we can do in such cases.
Henrique J. G. Ulbrich
April 30, 2020 at 1:41 am
Parasuraman, I agree with all the people, synthesized in the short and complete comments from Don Oser. Anyhow, you did a good job. Thanks for sharing.
Parasuraman S
April 30, 2020 at 9:28 pm
That's very nice of you! Many thanks for your comments!
Vincenzo
April 30, 2020 at 10:08 am
You are my favourite repair man . Your stories are always inspiring . Cheers
Parasuraman S
April 30, 2020 at 9:29 pm
Very nice of you, dear! Many thanks for your encouraging words!
Paris Azis
May 1, 2020 at 5:08 pm
Good job Parasuraman.Mark's comment above covered my aspect fully about this repair. Moreover I highly appreciate the reason for not messing yourself with the replacement of that "postage stamp" smd chip. Without the very expensive proper desoldering equipment available, this removal could end up fatal for the pcb. Always there is a very high risk for lifting pads, rendering the repair a real enigma afterwards. In other words,I appreciate your self-control by ignoring egotism and using plain logic...
Parasuraman S
May 4, 2020 at 6:05 pm
Very, very nice of you Paris Azis! Every word of your comments is very touching as it has the signature from your heart! Many, many thanks, dear!
HM
July 5, 2021 at 4:00 am
Thanks, for your detailed write up with pictures. I have same model AZ1047 which I had gifted to my Mom to listen her devotional CDs. Worked great for 4-5 years and now Radio & Cassette player works nice but when cd is inserted it spins and displays no. of tracks it holds but while pressing play or any other buttons didn’t make any move.
Could you please shed some light what could have gone wrong. Is it motor or something else .
Thankfully