18 August 2018

Marshall Woburn


This was a repair job I took from a music shop here in KD last year. They ask me whether I could check it. It belong to one customer of them. I glance at it and said sure, send it to my workshop I'll do what I can. From the simple controls my first thought was it must be a 1 or 5 watts tube amp or something.


When the bench time comes. I suddenly notice it doesn't have a 1/4 inch input jack. What the hell is this? I asked myself.  After some googling I realized it's a HiFi of some sort for processed audio from smartphones, Iplayer through wired or Bluetooth. What next Marshall? Smartphone,Fridge and Washing machines? Hmmmm..

The problem of this particullar Marshall Woburn was no power. I opened the back to look at the fuse if there is one. There is. I ordered the exact spec 1.6Amp fuse online and replaced it. A few days later I turn it ON the fuse blew as soon as the power switch flipped. I changed the fuse again. It works flawlessly. I'm guessing either our wall voltage(240VAC) fluctuates or the fuse rate specified by Marshall was too sensitive or the circuit itself is also too sensitive. I begin to have some assumption about what just happen. I mean this Marshall blew the same rated fuse in the customer location and in my workshop. I know if I stick with the same fuse I'll be supplying the customer a ton of 1.6Amp fuses. So I took out what I put in for a 2.0Amp fuse.


I also want to criticize Marshall for using SMPS in this unit. This kind of power supply is the same you find in PC. It's not touch safe for anyone to perform any repairs compared to the Linear Power Supply. I could only think one reason why Marshall chose to use SMPS in this unit. It's cheap! So my question would be when one day the SMPS blows up. Do the consumers needs to buy the whole board? You proud Woburn owners might want to ponder on that 5 to 7 years from now.


For musical enjoyment, If I were you, I'd stick with my conventional HiFi, PC Audio system or any brand that already has the reputation in the field. I would certainly stay away from any company that tries to ride the trend solely because there's money to be made in it.


Boo Marshall
yustech


 

7 comments:

Unknown said...

I have a Woburn that used to be a display unit. I was wondering if it can be converted to regular since it turns off after a couple of minutes

YusTech said...

I do not get what you mean?

Peterpie said...

Hi did you get it working? I have the same issue with an ex display

Fase said...

Can you tell me what the inscription is the resistor R19 is.

Fase said...

Can you tell me what the inscription is the resistor R19 is on the board.

YusTech said...

My apology Fase, I do not have anymore gut pictures of it.

Emerson Gilead said...

R19 = 5100 Woburn Marshall