Marantz Audio Digital Timer AT-5

kondratieff

New Member
Hi,

I've got a question. Purchased this Audio Timer a year or so ago. When i first got it, it worked. It powered on, display lit on and the timer switched on and off. Only recently I tried to hook it up for real and found out it did not work properly. Clock ran too slow and setting timer and clock appeared to be close to impossible. Any idea what could cause that or how to set it correctly?

Of course I have searched for a user manual and or service manual. Unfortunately I have not been able to track one down so far, therefore I decided to have a peak inside. The clean inside seemed fine, apart from 2 fuses that were burned. See pic. IMG_20180218_222505.jpg
I checked those two and they both read 11.6A 250v. The other one reads 100mA 250v. So before replacing any I want to make sure what the correct values should be. To me it seems they should all 3 have the same value but since I only know very little about the subject I might be totally wrong. The fuses seem to connector to the 2 outlets (where you can connect your stereo) and the voltage selector.
Any input about the workings of this device, any answers that put me in the direction for getting it to work properly are highly appreciated. If you happen to have the manual pls let me know.
 

Attachments

  • IMG_20180218_222418.jpg
    IMG_20180218_222418.jpg
    64.5 KB · Views: 19
  • IMG_20180218_222719.jpg
    IMG_20180218_222719.jpg
    60.3 KB · Views: 19
According to your photo, the fuses are 1A, 1A and a 63mA (0.063A) fuse. It is printed on the PCB. The 63mA fuse runs the timer circuitry and the relay switching of the outlets. Your 63mA fuse is fine as it wouldn't do a thing if that was blown.

The two 1A fuses will be for the outlets- someone has plugged in something over 220watts and blown them. Notice the rear panel, the rating is 200 watts switched- that corresponds to the fuse values at 1A (for a 220v country like yours).

There is an oddly placed capacitor in between the transformer and the timer PCB. It looks to be on a strange angle. Inspect it. I would definitely be starting at the power supply rectifier/filter and voltage regulator section. Difficulty in setting the timer is a clue your power supply was poor and likely riddled with ripple from a failed filter cap or a bad regulator.
 
Last edited:
According to your photo, the fuses are 1A, 1A and a 63mA (0.063A) fuse. It is printed on the PCB. The 63mA fuse runs the timer circuitry and the relay switching of the outlets. Your 63mA fuse is fine as it wouldn't do a thing if that was blown.

The two 1A fuses will be for the outlets- someone has plugged in something over 220watts and blown them. Notice the rear panel, the rating is 200 watts switched- that corresponds to the fuse values at 1A (for a 220v country like yours).

There is an oddly placed capacitor in between the transformer and the timer PCB. It looks to be on a strange angle. Inspect it. I would definitely be starting at the power supply rectifier/filter and voltage regulator section. Difficulty in setting the timer is a clue your power supply was poor and likely riddled with ripple from a failed filter cap or a bad regulator.

Thank you that was useful. So the fuses someone put in there were not right ones.
Those I can replace with proper ones.
I noticed the the strange position of the cap too, it somehow looked as it it has always been there though. Not sure if I'm smart enough to replace that one :) But thanks again for your explanation.
 
May not be of any help but I bought a Pioneer timer new years ago in Europe. When I brought it to the States, I had to switch the voltage, and also the 50-60 Hz switch. Without changing the Hz, it wouldn't keep time right.
 
May not be of any help but I bought a Pioneer timer new years ago in Europe. When I brought it to the States, I had to switch the voltage, and also the 50-60 Hz switch. Without changing the Hz, it wouldn't keep time right.

Thanks for your input and although voltage is correct the device was initially set to 60hz, here we use 50 so that I changed.
Have not been able to test that for a longer period of time yet.
Remains the issue with setting the clock and time. So I need to look at those caps.
 
You may also want to clean the pots and switches. The display on my Pioneer timer was doing goofy things a couple of years ago. Cleaning the switches took care of that. Wouldn't hurt to try it.
 
You may also want to clean the pots and switches. The display on my Pioneer timer was doing goofy things a couple of years ago. Cleaning the switches took care of that. Wouldn't hurt to try it.
I did clean those too. And after setting the device to 50 hertz it actually it runs on time now. Only the time changes as soon as I want to set the timer or sleep timer. Maybe one of the switches does not do what it is supposed to do. Needs some more work.
 
Update:
Ok now i have a working At-5.
  • Time can be set and it stays accurate.
  • Sleeptimer works, can be set to switch off between 0-59 minutes.
  • Timer clock can be set for switching whatever is hooked up on, however there's no way to set time for switching off apart from the sleep timer.
I'm sure I'm missing something very basic here, but just don't know what buttons to use for being able to set both time to switch on and then a time to switch off. Unless that was never the intention of this timer...
Anyone has any further ideas on this? That would be great. Thank you for reading.
 

Attachments

  • IMG_20180414_095208.jpg
    IMG_20180414_095208.jpg
    58.3 KB · Views: 7
Back
Top Bottom