Roland JC-55 amp stopped working

1. Check the power cable and ensure it is securely connected to both the amp and the power outlet. 2. Check the fuse and replace it if needed. 3. Check the power switch and ensure it is in the correct position. 4. Check the battery (if applicable) and replace it if needed. 5. If the amp is still not turning on, contact Roland customer service for further assistance.

Your Roland microcube AC is waste up

Google it and find the Service Manual, then get a Tech.

Sounds like a blown motherboard to me. It needs to go to the shop.

Hi, Quick Check. Very often the input socket which is soldered directly to the circuit board, will have a broken solder joint. This is common on a very large amount of equipment. Try waggling the plug about and seeing if the noise comes and goes.
Easy fix, re-solder joint. Permanent fix, connect socket to board with flying leads, or fix socket to board with hot glue or epoxy resin.
All the best, Chris the Fader.

What part of it got wet will determine the course of action.

If the whole unit were submerged, the unit may prove more time consuming to try to fix than to locate a used one. However, I have salvaged imersed laptops before. the procedure is not much different- make sure the unit is as dry as you can possibly make by blowing a fan on it for an extended period of time.- Days.

Once dried, use some contact cleaner on the jack contacts and interupts, any manual control and any switch.

You can then apply power. If nothing lights up, check and replace fuses as needed. Also check the power supply board for failed caps or rectifiers.

Once the power supply is known to be functional, systematically check the LCD display and the aspects of the amp that it controls. This board will be the most vulnerable and most likely to be the source of most issues you will encountr.

If the display survived intact, and amp does nto work, apply a signal to the inputs and trace the signal through the amp with a set of headphones set up with test prods. The problem will be where the signal stops.

Maybe your room is wired without an earth connection. Try it in other rooms or a friends house. If it works OK elsewhere, you need an electrician to check out your house, it may be dangerous. If it still does not work, look at your settings, and use low gain for testing.

https://www.amazon.in/Roland-JC-120B-Chorus-Guitar-Amplifier/dp/B00S0J6IS6


JC-120B 1975 or later

JC-120UT After 1984 - I haven't found the way to identify your serial number online. You may need to post a message on one of the many internet boards shown.

https://www.ssguitar.com/index.php?topic=2243.0

http://music-electronics-forum.com/t35754/https://www.gearslutz.com/board/so-many-guitars-so-little-time/181432-roland-jc-120-tough-date.html

JC=120UT /JA sold in Japan only.

https://www.gearslutz.com/board/so-many-guitars-so-little-time/181432-roland-jc-120-tough-date.html


ervicerepairmanuals.net/others/roland-jc-120ut-searvice-manual/






http://ervicerepairmanuals.net/others/roland-jc-120ut-searvice-manual

TRY GIOVANIA FOR HELP.

Check for corrosion on battery contacts. If this unit can use an AC adapter, often the switch contact in the power plug that connects the batteries when adapter is removed gets bent and fails to connect the batteries.